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Sökning: WFRF:(Elfman Mikael)

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1.
  • Abdel, Naseem S., et al. (författare)
  • Characterizations of new Delta E detectors for single-ion hit facility
  • 2014
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 318, s. 281-286
  • Tidskriftsartikel (refereegranskat)abstract
    • This paper describes the performance evaluation of new Delta E detectors to be used as pre-cell hit detectors in living cell irradiation experiments at the Lund Ion Beam Analysis facility (LIBAF). Using these detectors with a thickness down to 4.15 mu m fabricated at Lund University, an experiment was setup in which Delta E-detectors were used together with a stop E-detector in a telescope system under coincidence measurements. The characteristics of Delta E detectors were based on the optimal detection of the passage of 2.55 MeV protons. The results of these tests demonstrate that the detector telescope clearly separates the protons, this due to high signal-to-noise ratio and good energy resolution of the Delta E-detectors. The best performing detector was shown to have a detection efficiency of 95% at thickness of 9.7 mu m. This type of high-performing detector is suitable for the planned role of the Delta E-detector in the future cell irradiation experiments. (C) 2013 Elsevier B.V. All rights reserved.
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2.
  • Arteaga, Natalia, et al. (författare)
  • Applications of SU-8 in the development of a Single Ion Hit Facility
  • 2009
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 267:12-13, s. 2117-2121
  • Konferensbidrag (refereegranskat)abstract
    • The Lund Nuclear Microprobe (LNM) has been adapted to be used as a Single Ion Hit Facility (SIHF) for proton cell irradiation experiments at low dose. In order to test the capabilities of the system, Ni dot arrays and artificial cells have been fabricated with the photopolymer SU-8 and common lithographic techniques. The primary purpose of the Ni dot arrays was to determine the targeting accuracy of the beam in vacuum and in air. Additionally, this sample was employed to evaluate the system performance during cell target irradiation experiments. The Ni dot arrays were also used for beam characterization. The artificial cells were originally fabricated to test the software for cell recognition and localization, developed and implemented at the LNM. However, this sample became very functional to make small adjustments at the irradiation chamber for cell irradiation experiments. A description of the samples, fabrication procedure and applications are presented in this paper. (C) 2009 Elsevier B.V. All rights reserved.
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3.
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4.
  • Arteaga, Natalia, et al. (författare)
  • The new cell irradiation facility at the Lund nuclear probe
  • 2007
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 260:1, s. 91-96
  • Tidskriftsartikel (refereegranskat)abstract
    • The CELLION project is directed towards the studies on cellular response to targeted single ions. This paper gives an account of the modifications made at the Lund sub-micron beam line in order to create a Single Ion Hit Facility for biological applications within the CELLION project. The most relevant new feature is the specially developed software used to locate the cells. A program for cell recognition and localization that gives the coordinates of the centre of the cells has been designed. The recognition is made online. A picture taken by a microscope is used as input parameter for the recognition program. Using V79 Chinese hamster cells, the recognition procedure can be done in less than 0.5 s for a picture size of 800 x 600 pixels with approximately 96% efficiency. This paper also reports target accuracy test results and the first non-targeted irradiation procedure performed at the Lund sub-micron beam line. (c) 2007 Elsevier B.V. All rights reserved.
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5.
  • Auzelyte, Vaida, et al. (författare)
  • Exposure parameters for MeV proton beam writing on SU-8
  • 2006
  • Ingår i: Microelectronic Engineering. - : Elsevier BV. - 1873-5568 .- 0167-9317. ; 83:10, s. 2015-2020
  • Tidskriftsartikel (refereegranskat)abstract
    • Proton beam writing was performed on a lithographic resist to determine the main parameters required to achieve the minimum feature size, maximum pattern lateral density and maximum aspect ratio. A 2.5 MeV proton beam focused to sizes between 1.5 and 2.5 mu m was used to expose SU-8 negative resist. The number of protons per pixel was varied in the exposure of SU-8 with thicknesses between 5 and 95 pm. Patterns consisting of single pixels, single-pixel lines and multi-pixel areas with different densities were fabricated. The smallest structures achieved were posts 1.5 pin in diameter with 4:1 structure-space ratio in 15 pm thick resist and the highest aspect ratio structures of 20:1 in 40 pm resist were produced. It was found that the minimum feature size depended only on the beam size, and +/- 10% post size accuracy could be achieved within 40-70% variation of the number of protons. MeV proton beam allows a direct fabrication of complex shapes without a mask in single-step irradiation and. in addition, no proximity correction is needed. We present examples of MeV proton beam written single and multi-pixel microstructures with easily reproducible high aspect ratios and densities. (c) 2006 Elsevier B.V. All rights reserved.
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6.
  • Auzelyte, Vaida, et al. (författare)
  • Fabrication of phosphor micro-grids using proton beam lithography
  • 2006
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 242:1-2, s. 253-256
  • Tidskriftsartikel (refereegranskat)abstract
    • A new nuclear microscopy technique called ion photon emission microscopy or IPEM was recently invented. IPEM allows analysis involving single ions, such as ion beam induced charge (IBIC) or single event upset (SEU) imaging using a slightly modified optical microscope. The spatial resolution of IPEM is currently limited to more than 10 mu m by the scattering and reflection of ion-induced photons, i.e. light blooming or spreading, in the ionoluminescent phosphor layer. We are developing a '' Microscopic Gridded Phosphor '' (also called Black Matrix) where the phosphor nanocrystals are confined within the gaps of a micrometer scale opaque grid, which limits the amount of detrimental light blooming. MeV-energy proton beam lithography is ideally suited to lithographically form masks for the grid because of high aspect ratio, pattern density and sub-micron resolution of this technique. In brief, the fabrication of the grids was made in the following manner: (1) a MeV proton beam focused to 1.5-2 mu m directly fabricated a matrix of pillars in a 15 mu m thick SU-8 lithographic resist; (2) 7:1 aspect ratio pillars were then formed by developing the proton exposed area; (3) Ni (Au) was electrochemically deposited onto Cu-coated Si from a sulfamate bath (or buffered CN bath); (4) the SU-8 pillars were removed by chemical etching; finally (5) the metal micro-grid was freed from its substrate by etching the underlying Cu layer. Our proposed metal micro-grids promise an order-of-magnitude improvement in the resolution of IPEM.
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7.
  • Auzelyte, Vaida, et al. (författare)
  • On-line measurement of proton beam current in pA range
  • 2006
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 249, s. 760-763
  • Tidskriftsartikel (refereegranskat)abstract
    • A MeV proton beam with a current in the range of fA-nA is usually measured using a secondary beam signal that is dependent on a sample or requires noise-free accurate charge integration in a Faraday cup. We propose a simple on-line beam current measurement setup that can be used to directly measure beam current during ion beam analysis. A fast beam blanker is used to modulate the beam position after the last set of collimator slits in and out of a mini Faraday cup connected to fA-sensitive electrometer. Less than 100 fA current can be measured during an undisturbed irradiation with kHz sampling frequency. The fast, simple and easily controlled current measurement set-up is going to be routinely used for ion beam analysis and modification at the new Lund sub-micron beam line. (c) 2006 Elsevier B.V. All rights reserved.
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8.
  • Auzelyte, Vaida, et al. (författare)
  • The beam blanking system for microlithography at Lund Nuclear microprobe
  • 2004
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 219-20, s. 485-489
  • Tidskriftsartikel (refereegranskat)abstract
    • A new beam blanking system was installed at the Lund Nuclear Microprobe and employed in proton beam lithography (PBL) for polymer microstructures fabrication. The blanker consists of two parallel plates connected to a high voltage generator. Measurement of the beam blanking time on a sample was performed by means of the standard PIXE system. The beam is blanked and returns to a sample within 200 ns. The blanking system is designed for the new sub-micrometer beamline under installation in the accelerator laboratory. A number of pilot MeV ion beam lithography experiments were performed to illustrate the possibility to use the blanking system in combination with the existing data acquisition and scanning system. A 2.5 MeV proton beam was used to irradiate 50 mum SU-8 negative resist. The blanker was shown to be a necessary part of the lithography system. It enables blanking between each pixel and hence fabrication of various patterns down to a single pixel. The blanker has significantly simplified beam control and enhanced process time and spatial resolution. Three-dimensional microstructures with 20:1 aspect ratio were fabricated.
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9.
  • Barbin, Vincent, et al. (författare)
  • Biological record of added manganese in seawater: a new efficient tool to mark in vivo growth lines in the oyster species Crassostrea gigas
  • 2008
  • Ingår i: International Journal of Earth Sciences. - : Springer Science and Business Media LLC. - 1437-3254 .- 1437-3262. ; 97:1, s. 193-199
  • Tidskriftsartikel (refereegranskat)abstract
    • The biological response of increased manganese in seawater was tested experimentally with the oyster species Crassostrea gigas by adding, once per day, a fixed quantity of MnCl2 to the container where the oysters were living. Uptake of Mn2+ in the shell was traced with cathodoluminescence and quantified with a high spatial resolution proton microprobe. The daily addition of MnCl2 resulted in the visualization of distinct growth increments seen simultaneously in both the calcitic shell and the aragonitic ligament. A relation was observed between the addition of Mn2+ to the seawater and incorporation of Mn in the mineral part of the shell. Thus, addition of MnCl2 to seawater is an efficient tool to mark in vivo growth increments in bio-mineralised carbonates.
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10.
  • Borysiuk, Maciek, et al. (författare)
  • Evaluation of a setup for pNRA at LIBAF for applications in geosciences
  • 2014
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 332, s. 202-206
  • Tidskriftsartikel (refereegranskat)abstract
    • A new setup for photon tagged nuclear reaction analysis pNRA is being developed at Lund's ion beam analysis facility LIBAF. Particle induced gamma ray emission PIGE and nuclear reaction analysis NRA are two methods that have been extensively used for light isotope measurement in ion beam analysis IBA. There is an abundance of nuclear reactions between light elements and MeV protons, deuterons and alpha particles. This means that in principle all elements from lithium all the way up to chlorine can be analyzed using those techniques. Detection limits can be improved for some elements, if those two methods are fused together into pNRA. The new setup for pNRA will benefit from advances in detector technology that occurred during the last 20 years. A LaBr3 scintillator detector and an annular double sided silicon strip detector DSSSD are used in coincidence to detect a gamma and a charged particle respectively. Both detectors are connected to a VME based data acquisition system. Of primary interest in this work is the analysis of isotopic ratios of light elements in geological samples, which are usually thick with a complex matrix. This setup can be for instance used to measure isotopic fractionation of oxygen and boron. We will present the setup and discuss its capabilities. (C) 2014 The Authors. Published by Elsevier B.V.
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11.
  • Borysiuk, Maciek, et al. (författare)
  • Hydrogen analysis and profiling with a position sensitive detector
  • 2013
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 306, s. 49-53
  • Tidskriftsartikel (refereegranskat)abstract
    • The double sided silicon strip detector (DSSSD) is a segmented silicon detector commonly used in the fields of high energy physics and nuclear physics. This type of detector is used for analysis of reactions produced by charged particles. This makes it well suited for a number of analytical methods commonly used in ion beam analysis (IBA), such as Rutherford Backscattering (RBS) and elastic recoil detection (ERDA). One such detector was installed and tested at Lund Ion Beam Analysis Facility (LIBAF) recently. This is a modification to the existing setup used to measure hydrogen concentrations and depth profiles. When completed it will be used primarily for geological applications. Exact knowledge of the hydrogen content is important in a number of fields, but high enough accuracy can be difficult to achieve with most methods. In IBA normally some variant of ERDA, such as the proton-proton (p-p) coincidence method is used. We describe how the p-p coincidence technique was optimized to get the most out of our experimental setup. Previously this type of spectroscopy has been performed with two detector channels. In the present setup we expand that number from 2 to 96 channels, 64 on the front and 32 on the back of the detector. The intersecting strips give 2048 distinct detector elements or 1024 possible coincidences as dictated by the reaction kinematics. This increase in complexity requires a more detailed data analysis but it rewards us with higher sensitivity and a better background suppression. (C) 2013 Elsevier B.V. All rights reserved.
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12.
  • Borysiuk, Maciek, et al. (författare)
  • Optimization of O-18 measurement using NRA for studies of isotopic content in fossil meteorites
  • 2011
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 269:20, s. 2229-2232
  • Konferensbidrag (refereegranskat)abstract
    • In this work, we discuss the possibility of a new approach to measuring oxygen isotope ratios in fossil meteorite samples, specifically one based on nuclear reaction analysis (NRA). Variations of oxygen ratios within meteoritic chromite grains can help to determine the type of meteorite to which the grains originally belonged. In this work, we have evaluated the possibility to use the reaction O-18(p, alpha)N-15 just above the 846 keV resonance to estimate the relative oxygen-18 content in a number of test samples. Another technique has to be employed for oxygen-16 measurements. A large area segmented silicon detector is used to detect the produced alpha particles. Results of the experimental O-18 measurements for a number of samples including four extraterrestrial chromite grains are presented and compared with SIMNRA simulations. The advantage of a segmented silicon detector in the form of inherent pile-up suppression can be clearly seen in the current work. (C) 2011 Elsevier B.V. All rights reserved.
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13.
  • Borysiuk, Maciek, et al. (författare)
  • Preliminary results of oxygen isotope ratio measurement with a particle-gamma coincidence method
  • 2015
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 348, s. 269-272
  • Tidskriftsartikel (refereegranskat)abstract
    • The possibility to study variations in the oxygen isotopic ratio with photon tagged nuclear reaction analysis (pNRA) is evaluated in the current work. The experiment described in the article was performed at Lund Ion Beam Analysis Facility (LIBAF) with a 2 MeV deuteron beam. Isotopic fractionation of light elements such as carbon, oxygen and nitrogen is the basis of many analytical tools in hydrology, geology, paleobiology and paleogeology. IBA methods provide one possible tool for measurement of isotopic content. During this experimental run we focused on measurement of the oxygen isotopic ratio. The measurement of stable isotopes of oxygen has a number of applications; the particular one driving the current investigation belongs to the field of astrogeology and specifically evaluation of fossil extraterrestrial material. There are three stable isotopes of oxygen; O-16, O-17 and O-18. We procured samples highly enriched with all three isotopes. Isotopes O-16 and O-18 were easily detected in the enriched samples, but no significant signal from O-17 was detected in the same samples. The measured yield was too low to detect O-18 in a sample with natural abundances of oxygen isotopes, at least in the current experimental setup, but the spectral line from the reaction with O-16 was clearly visible. (C) 2015 Elsevier B.V. All rights reserved.
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14.
  • Boschi, Samuele, et al. (författare)
  • Popigai impact ejecta layer and extraterrestrial spinels recovered in a new Italian location—The Monte Vaccaro section (Marche Apennines, Italy)
  • 2019
  • Ingår i: 250 Million Years of Earth History in Central Italy: Celebrating 25 Years of the Geological Observatory of Coldigioco. - : Geological Society of America. - 0072-1077. ; 542, s. 355-367
  • Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
    • The Popigai (100 km in diameter) and the Chesapeake Bay (40–85 km diameter) impact structures formed within ~10–20 k.y. in the late Eocene during a 2 m.y. period with enhanced flux of 3He-rich interplanetary dust to Earth. Ejecta from the Siberian Popigai impact structure have been found in late Eocene marine sediments at numerous deep-sea drilling sites around the globe and also in a few marine sections outcropped on land, like the Massignano section near Ancona in Italy. In the Massignano section, the Popigai layer is associated with an iridium anomaly, shocked quartz, and abundant clinopyroxene-bearing (cpx) spherules, altered to smectite and flattened to “pancake spherules.” The ejecta are also associated with a significant enrichment of H-chondritic chromite grains (>63 µm), likely representing unmelted fragments of the impactor. The Massignano section also contains abundant terrestrial chrome-spinel grains, making reconstructions of the micrometeorite flux very difficult. We therefore searched for an alternative section that would be more useful for these types of studies. Here, we report the discovery of such a section, and also the first discovery of the Popigai ejecta in another locality in Italy, the Monte Vaccaro section, 90 km west of Ancona. The Monte Vaccaro section biostratigraphy was established based on calcareous nannoplankton, which allowed the identification of a sequence of distinct bioevents showing a good correlation with the Massignano section. In both the Monte Vaccaro and Massignano sections, the Popigai ejecta layer occurs in calcareous nannofossil zone CNE 19. The ejecta layer in the Monte Vaccaro section contains shocked quartz, abundant pancake spherules, and an iridium anomaly of 700 ppt, which is three times higher than the peak Ir measured in the ejecta layer at Massignano. In a 105-kg-size sample from just above the ejecta layer at Monte Vaccaro, we also found an enrichment of H-chondritic chromite grains. Because of its condensed nature and low content of terrestrial spinel grains, the Monte Vaccaro section holds great potential for reconstructions of the micrometeorite flux to Earth during the late Eocene using spinels.
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15.
  • Bulow, K, et al. (författare)
  • The penetration depth and lateral distribution of pigment related to the pigment grain size and the calendering of paper
  • 2002
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - 0168-583X. ; 189, s. 308-314
  • Tidskriftsartikel (refereegranskat)abstract
    • The interaction of ink and newspaper has been investigated and the specific question of penetration of ink into the paper has been addressed with a nuclear microprobe using particle induced X-ray emission, The penetration depth of the newsprint is a critical factor in terms of increasing the quality of newsprint and minimising the amount of ink used. The objective of the experiment was to relate the penetration depth of pigment with the calendering of the paper, The dependence of the penetration depth on the pigment grain size was also Studied, To Study the penetration depth of pigment in paper, cyan ink with Cu as a tracer of the coloured pigment was used, For the study of the penetration depth dependence of pigment size. specially grounded Japanese ink with well-defined pigment grain size was used. This was compared to Swedish ink with pigment grains with normal size-distribution, The results show that the calendering of the paper considerably affects the penetration depth of ink. (C) 2002 Elsevier Science B.V. All rights reserved.
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16.
  • Chernikova, Dina, 1982, et al. (författare)
  • Testing of small detectors with glass rod light guides for multiplicity measurement purposes
  • 2012
  • Ingår i: Proceedings of The 53nd Annual Meeting of the Institute of Nuclear Materials Management.
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
    • In this paper we investigate the applicability of small scintillators with glass rod lightguides to measure both neutrons and gamma rays from the sample. Experimental test ofthese detectors and their suitability for the task can be performed at Lund University usingnatural uranium rods, therefore the MCNPX simulation set-up corresponds to the Lund con-figuration. The long-term goal of this research is to develop a method of joint-multiplicitycounting for fuel evaluation into a technology capable of quantifying plutonium in the fuelpool, where a lot of factors, such as presence of neutron absorbers (boron acid), can affect al-most all parameters, such as multiplication etc. Therefore, part of the present investigationswas devoted to the development of a direct method for determination of the concentrationof boron acid in the fuel pool using scintillation detectors with further correction of mea-surement results. For this purpose we suggest a method which utilizes a relation betweengamma lines with energy of 480 keV and 2.23 MeV for the direct evaluation of concentrationof boron acid in water. Test results of the new method, and an answer to questions regardingthe ability to measure both neutron and gamma rays using small scintillation detectors withglass rod light guides are provided in this paper.
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17.
  • De La Rosa, Nathaly, et al. (författare)
  • Lithium analysis using a double-sided silicon strip detector at LIBAF
  • 2017
  • Ingår i: Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 404, s. 29-33
  • Tidskriftsartikel (refereegranskat)abstract
    • Quantification and mapping possibilities of lithium in geological material, by Nuclear Reaction Analysis (NRA), was evaluated at the Lund Ion Beam Analysis Facility (LIBAF). LiF and two Standard Reference Materials, (SRM 610 and SRM 612) were used in the investigation. The main part of the data was obtained at the beam energy 635keV studying the high Q-value reaction 7Li(p, α)4He, but reaction yield and detection limits were also briefly investigated as a function of the energy. A double-sided silicon strip detector (DSSSD) was used to detect the α-particles emitted in the reaction in the backward direction. The combination of the high Q-value, a reasonably good cross-section and the possibility to use a high beam current have been demonstrated to allow for measurement of concentrations down below 50ppm. Proton energies below 800keV were demonstrated to be appropriate energies for extracting lithium in combination with boron analysis.
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18.
  • Dunca, Elena, et al. (författare)
  • Using ocean quahog (Arctica islandica) shells to reconstruct palaeoenvironment in A-resund, Kattegat and Skagerrak, Sweden
  • 2009
  • Ingår i: International Journal of Earth Sciences. - : Springer Science and Business Media LLC. - 1437-3254 .- 1437-3262. ; 98:1, s. 3-17
  • Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
    • Shells of Arctica islandica collected between 1884 and 2004 from A-resund, Kattegat and Skagerrak (Swedish West Coast) were used to monitor local climate variations and the influence of human activities on the local environment. For this purpose, we analysed the growth, structure and chemical composition of these shells and compared them with shells collected from Kiel Bay, Norway and Iceland. The growth rate of the studied shells registers an NAO periodicity of ca 8 years. However, the observed signal is weak because of other environmental interferences that are either of natural or anthropogenic origin. For example, the oxygen isotope ratios show temperature fluctuation, but also the influx of low salinity water. Higher contents of S, N, Cu, Zn, As, Cd and P in shell portions formed during the last century are related to human activities such as mining and industrial development. Our study indicates that in order to use Arctica shells as archives of climate change it is necessary to study the full range of environmental data that is recorded in the shells by using a multi element and isotope approach in combination with different analytical techniques including investigation of growth rates and shell structure.
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19.
  • Elfman, Mikael, et al. (författare)
  • A tailored 200 parameter VME based data acquisition system for IBA at the Lund Ion Beam Analysis Facility - Hardware and software
  • 2016
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 371, s. 148-152
  • Tidskriftsartikel (refereegranskat)abstract
    • With the recent advances towards modern Ion Beam Analysis (IBA), going from one- or few-parameter detector systems to multi-parameter systems, it has been necessary to expand and replace the more than twenty years old CAMAC based system. A new VME multi-parameter (presently up to 200 channels) data acquisition and control system has been developed and implemented at the Lund Ion Beam Analysis Facility (LIBAF). The system is based on the VX-511 Single Board Computer (SBC), acting as master with arbiter functionality and consists of standard VME modules like Analog to Digital Converters (ADC's), Charge to Digital Converters (QDC's), Time to Digital Converters (TDC's), scaler's, IO-cards, high voltage and waveform units. The modules have been specially selected to support all of the present detector systems in the laboratory, with the option of future expansion. Typically, the detector systems consist of silicon strip detectors, silicon drift detectors and scintillator detectors, for detection of charged particles, X-rays and γ-rays. The data flow of the raw data buffers out from the VME bus to the final storage place on a 16 terabyte network attached storage disc (NAS-disc) is described. The acquisition process, remotely controlled over one of the SBCs ethernet channels, is also discussed. The user interface is written in the Kmax software package, and is used to control the acquisition process as well as for advanced online and offline data analysis through a user-friendly graphical user interface (GUI). In this work the system implementation, layout and performance are presented. The user interface and possibilities for advanced offline analysis are also discussed and illustrated.
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20.
  • Elfman, Mikael (författare)
  • Development of a Data Aquisition System at a Nuclear Microprobe with Applications in the Geo- and Biosciences
  • 2001
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • This thesis is divided in two parts, one that deals with the development of the new data acquisition system at Lund Nuclear Microprobe, and a second part that deals with different applications. A CAMAC based data acquisition system has been installed at the Lund Nuclear Microprobe facility. The system is a true multi-parameter and multi-detector system with fast FERA bus readout and in crate memory buffer. Each event in a detector produces a gate to all of the multiple parameters that should be acquired in coincidence. The system reads and tags each event and scaler word with X-Y position. The charge is measured by a current digitiser connected to a scaler. The beam scanning part is software controlled through a Timed D/A converter, this allows for fast scanning of the beam, this unit generates the coordinates. The work with the development of this system is described. Applications in various fields are discussed: Otolith analyses and micro fossil analyses. To know a fish life history (or the age of the fish) is an important factor in assessment of fish populations. Otolith growth is a combination of seasonal and daily increments combined with random events. The otolith develops in rings from its center (incremental zone), a tiny ring presents when the fish hatches. The Sr level in this point is transferred from the mother. The analyses of otoliths from Salmo trutta and Anguilla anguilla are reported.
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21.
  • Elfman, Mikael, et al. (författare)
  • The Lund Nuclear Microprobe sub-micron set-up. Part III: Sample stage, optical imaging and detector configuration in the experimental chamber
  • 2005
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 231:1-4, s. 14-20
  • Tidskriftsartikel (refereegranskat)abstract
    • A new sub-micron beamline for high-resolution nuclear microprobe applications has been constructed at the Lund nuclear microprobe facility. The design and construction of the main experimental chamber.. sample viewing system and computer controlled precision sample stage movement is presented in this paper. The chamber is especially designed for using a large area annular HPGe detector. The advantages with such a large area detector are discussed and illustrated. In addition the quality of the optical viewing and the precision sample stage is discussed.
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22.
  • Engstedt, Olof, et al. (författare)
  • Assessment of natal origin of pike (Esox lucius) in the Baltic Sea using Sr:Ca in otoliths
  • 2010
  • Ingår i: Environmental Biology Of Fishes. - : Springer Science and Business Media LLC. - 0378-1909 .- 1573-5133. ; 89:3-4, s. 547-555
  • Konferensbidrag (refereegranskat)abstract
    • Spawning habitat of pike (Esox lucius) in the Baltic Sea include brackish water bays, brooks and rivers. Elevated salinity concentrations are one of several stressors that might increase the use and importance of freshwater habitats for spawning. In the Baltic Sea, one of the largest brackish seas in the world, freshwater species like pike, perch (Perca fluviatilis), whitefish (Coregonus sp), bream (Abramis brama), ide (Leuciscus idus), roach (Rutilus rutilus) and burbot (Lola iota) all undertake spawning migrations to freshwater. However, over the last decades populations densities of these species have declined, and recruitment failure has been argued to be at least part of the problem. The importance of brooks and rivers as spawning areas for these species have not been quantified and set in relation to spawning success in brackish bays. In this study, we collected 175 adult pike (Esox lucius) on their foraging grounds in the sea. Fish were collected in two regions on the Baltic coast, more than 600 km apart. Subsequently we determined their origin (freshwater or marine) using otolith chemistry. Sagittal otoliths were analysed for strontium using the PIXE-method. The results show that 80 of the 175 pike were recruited in freshwater, and several of the larger specimens showed reoccurring migration behaviour. Data show that freshwater is an important recruitment habitat for Baltic Sea pike, suggesting that habitat improvements in rivers entering the Baltic Sea might significantly contribute to population restoration.
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23.
  • Frost, Robert, et al. (författare)
  • Development of a Pelletron-based compact neutron source : At the Nuclear Applications Laboratory, Lund University
  • 2023
  • Ingår i: Journal of Neutron Research. - 1023-8166. ; 24:3-4, s. 281-287
  • Tidskriftsartikel (refereegranskat)abstract
    • The Applied Nuclear Physics Group at Lund University is constructing a prototype CANS (Compact Accelerator-driven Neutron Source). The CANS is based around a 3 MV, single-ended, Pelletron accelerator, which is used to impinge a 2.8 MeV deuterium beam into a beryllium target. The anticipated neutron production will be on the order of 1010 n/s in 4π sr. A further upgrade to the ion source of the Pelletron is expected to increase neutron production to 1011 n/s. Neutron energies will be up to 9 MeV with peak emission at ∼5 MeV. Shielding and moderation will be provided by a large water tank surrounding the target, with three exit ports to allow neutrons of different energies to be directed to experiments. The design is supported by simulation results which predict fast-neutron fluxes of 9×104 to 5×106 n/cm2/s, and thermal-neutron fluxes of 1×104 to 5×104 n/cm2/s to be readily obtainable with a 10 µA deuteron beam.
  •  
24.
  •  
25.
  • Genberg, Johan, et al. (författare)
  • Development of graphitization of μg-sized samples at Lund University
  • 2010
  • Ingår i: Radiocarbon. - 0033-8222. ; 52:3, s. 1270-1276
  • Konferensbidrag (refereegranskat)abstract
    • To be able to successfully measure radiocarbon with accelerator mass spectrometry (AMS) in atmospheric aerosol samples, graphitization of small sample sizes (< 50 µg carbon) must provide reproducible results. At Lund University, a graphitization line optimized for small samples has been constructed. Attention has been given to minimize the reduction reactor volume and each reactor is equipped with a very small pressure transducer that enables constant monitoring of the reaction. Samples as small as 25 µg of carbon have been successfully analyzed, and the mass detection limit of the system has probably not been reached.
  •  
26.
  • Glave, Stefan, et al. (författare)
  • Quality indicators for woodwind reed material
  • 1999
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - 0168-583X. ; 150:1-4, s. 673-678
  • Tidskriftsartikel (refereegranskat)abstract
    • For the generation of sound, some woodwind musical instruments, e.g. oboe, bassoon, clarinet and saxophone, are provided with mouthpieces made from reeds. These reeds are the culms of Arundo donax, a tall, cane-like perennial grass. A general problem is that the material is of varying quality, yet externally differences cannot be observed. Hence, large proportions of the prepared reeds are unusable. One hypothesis is that the changes in quality are correlated with differences in the chemical and anatomical structure of the tissue. Therefore, a comparison of superior and inferior mouthpieces, used by professional musicians, was undertaken to determinate potential indicators of quality. Nuclear microprobe analysis of reeds was carried out and complemented by scanning electron and light microscopy. The elemental levels of Si, P, S, Cl, K and Ca were compared between good and poor mouthpieces using appropriate statistical tests. No statistically significant differences could be identified. Microscopical observations showed that partial occlusion of vessels by tylose formation was associated with material deemed unusable.
  •  
27.
  • Goderis, Steven, et al. (författare)
  • Globally distributed iridium layer preserved within the Chicxulub impact structure
  • 2021
  • Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 7:9
  • Tidskriftsartikel (refereegranskat)abstract
    • The Cretaceous-Paleogene (K-Pg) mass extinction is marked globally by elevated concentrations of iridium, emplaced by a hypervelocity impact event 66 million years ago. Here, we report new data from four independent laboratories that reveal a positive iridium anomaly within the peak-ring sequence of the Chicxulub impact structure, in drill core recovered by IODP-ICDP Expedition 364. The highest concentration of ultrafine meteoritic matter occurs in the post-impact sediments that cover the crater peak ring, just below the lowermost Danian pelagic limestone. Within years to decades after the impact event, this part of the Chicxulub impact basin returned to a relatively low-energy depositional environment, recording in unprecedented detail the recovery of life during the succeeding millennia. The iridium layer provides a key temporal horizon precisely linking Chicxulub to K-Pg boundary sections worldwide.
  •  
28.
  • Golubev, Pavel, et al. (författare)
  • First results from the Lund NMP particle detector system
  • 2009
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 267:12-13, s. 2065-2068
  • Konferensbidrag (refereegranskat)abstract
    • The design and first results from a Double Sided Silicon Strip Detector (DSSSD) recently installed at the Lund Nuclear Microprobe facility (NMP) are presented. The detector has 64 sector strips and 32 ring strips, which in combination give more than 2000 detector cells, each with characteristics comparable with a standard surface barrier detector (SBD). The detector has been tested both with radioactive sources and with different ion beams and energies. The most striking features are the high rate virtually pile-up free operation and also the possibility of detailed measurement of angular distributions. (C) 2009 Elsevier B.V. All rights reserved.
  •  
29.
  • Hode, Tomas, et al. (författare)
  • Development of a non-destructive micro-analytical method for stable carbon isotope analysis of transmission electron microscope (TEM) samples
  • 2009
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X .- 1872-9584. ; 267:19, s. 3375-3382
  • Tidskriftsartikel (refereegranskat)abstract
    • The biogenicity of ancient morphological microfossil-like objects can be established by linking morphological (e.g. cell remnants and extracellular polymeric matrix) and chemical (e.g. isotopes, biomarkers and biominerals) evidence indicative of microorganisms or microbial activity. We have developed a non-destructive micro-analytical ion beam system capable of measuring with high spatial resolution the stable carbon isotope ratios of thin samples used for transmission electron microscopy. The technique is based on elastic scattering of alpha particles with an energy of 2.751 MeV. At this energy the C-13 cross section is enhanced relative to the pure Rutherford cross section for C-13, whereas the C-12 cross section is reduced relative to its pure Rutherford cross section. Here we report the initial results of this experimental approach used to characterize ultramicrotomed sections of sulfur-embedded graphite and microbial cells. (C) 2009 Elsevier B.V. All rights reserved.
  •  
30.
  • Jaric, Ivan, et al. (författare)
  • Insight into Danube sturgeon life history: trace element assessment in pectoral fin rays
  • 2011
  • Ingår i: Environmental Biology of Fishes. - : Springer Science and Business Media LLC. - 0378-1909 .- 1573-5133. ; 90:2, s. 171-181
  • Tidskriftsartikel (refereegranskat)abstract
    • Sturgeon populations in the Danube River have experienced severe decline during the last several decades, mostly due to the poorly regulated fishery, river fragmentation and water pollution. This study focuses on gaining better understanding of sturgeon life history primarily by addressing the assessment of microelement accumulation in sturgeon pectoral fin rays, especially of strontium and calcium, as a method that can reveal migration patterns of anadromous sturgeons. Analysis was performed on pectoral fin samples of three anadromous Danube sturgeon species (beluga, Russian sturgeon and stellate sturgeon) by the use of a Nuclear Microprobe technique. The most frequent pattern in analyzed samples was represented by a low Sr:Ca ratio in the innermost annuli, followed by an increased ratio in the middle annuli segment, and often with a decreased ratio in the outermost annuli. Probability density estimate has revealed three distinguished maxima of the Sr: Ca ratio, 7.08x10(-3), 8.98x10(-3) and 9.90x10(-3), which might correspond, respectively, to fresh, brackish and saltwater. Although the analysis of the Sr: Ca ratio in sturgeon pectoral fin rays has revealed changes that might indicate probable migration between habitats with different water salinity, further studies are needed for improvement of this method. This study represents the first analysis of this kind that was conducted on sturgeon species from the Black Sea basin.
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31.
  • Kristiansson, Per, et al. (författare)
  • A pre-sample charge measurement system for quantitative NMP-analysis
  • 2010
  • Ingår i: Nuclear Instruments & Methods in Physics Research Section B-Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 268:11-12, s. 1727-1730
  • Konferensbidrag (refereegranskat)abstract
    • In many IBA applications the main aim is to obtain quantitative figures characterizing the sample. Normally charge, i.e. number of probe particles, is used for normalization and is measured either by collecting the charge deposited in the sample or by collecting the particle in a post-sample Faraday cup or in combination. Both these techniques have drawbacks and results can be difficult to compare for samples with different matrix composition. In this work, we present an upgraded design and test results from the Lund NMP pre-sample charge measurement system. The system presented is based on a pre-sample beam deflection controlled by the beam scanning system for the nuclear microprobe. It can be operated in different modes, but during normal operation the beam is blanked once per pixel and the corresponding charge is collected during the beam-off period. The system does not only measure an average of the beam current during data collection, but actually a pixel-by-pixel normalization is possible. Data of the system performance are presented and in addition illustrations of how quantitative measurements both for PIXE and elastic scattering can be made more reliable. (C) 2010 Elsevier B.V. All rights reserved.
  •  
32.
  • Kristiansson, Per, et al. (författare)
  • Development of a system for determination of the C-13/C-12 isotopic ratio with high spatial resolution
  • 2004
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 219-20, s. 561-566
  • Tidskriftsartikel (refereegranskat)abstract
    • Stable carbon isotopes play an important role in the interpretation of biological activity, particularly when the fossil record is studied. In combination with morphological and chemical data, isotopic information can be useful in paleontology and astrobiology. In this paper the development of a microanalytical ion beam system for the measurement of the carbon isotope ratio with high spatial resolution and good statistics is presented. The technique used is elastic scattering of alpha particles with an energy of 2.75 MeV. At this energy the C-13 cross-section is enhanced relative to the Rutherford cross-section and while the C-12 cross-section is reduced. The optimisation of the system is described, including sample preparation and the design of the particle detection system for high efficiency combined with good energy resolution. Finally, some results from the initial test run of the system are shown and discussed. (C) 2004 Elsevier B.V. All rights reserved.
  •  
33.
  • Kristiansson, Per, et al. (författare)
  • Quantitative hydrogen analysis in minerals based on a semi-empirical approach
  • 2013
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 306, s. 253-256
  • Tidskriftsartikel (refereegranskat)abstract
    • Hydrogen normally occurs as hydroxyl ions related to defects at specific crystallographic sites in the structures, and is normally characterized by infrared spectroscopy (FTIR). For quantification purposes the FTIR technique has proven to be less precise since calibrations against independent methods are needed. Hydrogen analysis by the NMP technique can solve many of the problems, due to the low detection limit, high lateral resolution, insignificant matrix effects and possibility to discriminate surface-adsorbed water. The technique has been shown to work both on thin samples and on thicker geological samples. To avoid disturbance from surface contamination the hydrogen is analyzed inside semi-thick geological samples. The technique used is an elastic recoil technique where both the incident projectile (proton) and the recoiled hydrogen are detected in coincidence in a segmented detector. Both the traditional annular system with the detector divided in two halves and the new double-sided silicon strip detector (DSSSD) has been used. In this work we present an upgraded version of the technique, studying two sets of mineral standards combined with pre-sample charge normalization. To improve the processing time of data we suggest a very simple semi-empirical approach to be used for data evaluation. The advantages and drawbacks with the approach are discussed and a possible extension of the model is suggested. (C) 2013 Elsevier B.V. All rights reserved.
  •  
34.
  • Kristiansson, Per, et al. (författare)
  • The implementation of a DSSSD in the upgraded boron analysis at LIBAF for applications in geochemistry
  • 2014
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X .- 1872-9584. ; 332, s. 207-211
  • Tidskriftsartikel (refereegranskat)abstract
    • Interest in high spatial resolution boron analyses from a geochemical perspective is related to the recognition of boron as an important tracer of chemical recycling in the Earth, due to the high solubility of boron in aqueous fluids and silicate melts. Although boron is not a nominal component in common silicates they may still contain significant B-concentrations and hence constitute important boron reservoirs in the deeper parts of the Earth. Boron analyses have been performed at the Lund Ion Beam Analytical Facility for almost 20 years. For the analysis the nuclear reaction p+B-11 is used with beam energy just below 700 keV where the reaction has a broad resonance. In this paper we describe an upgrade of the system with a double sided silicon strip detector, which allows for much higher count rates compared to the old annular surface detector based system. A gain close to 20 in the data rate allows for high resolution mapping of boron distributions in crystals. This is illustrated by a number of examples. In addition, the detection limits for boron in geological samples are improved, now around 5 ppmw. In this work we address issues with data quality, especially charge normalization, lifetime correction and subtraction of different background components. (C) 2014 The Authors. Published by Elsevier B.V.
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35.
  • Limburg, K E, et al. (författare)
  • New Insights into Fish Ecology via Nuclear Microscopy of Otoliths
  • 2003
  • Ingår i: AIP Conf. Proc. -- August 26, 2003. - : AIP. ; 680, s. 339-342
  • Konferensbidrag (refereegranskat)abstract
    • Otoliths, or earstones, are small, biogenic concretions of aragonitic calcium carbonate precipitated on a protein matrix. Otoliths form part of the hearing and balance system in teleost fishes, and grow as the fish grow, providing a continuous biochronology of growth. Various elements are entrained in minor and trace quantities. In particular, strontium is a useful scalar of habitat use when variable environmental gradients exist. By mapping elemental concentrations and ratios with the Lund nuclear microprobe, we have used strontium in many cases as a proxy for salinity, because Sr:Ca values are roughly an order of magnitude higher in marine vs most fresh waters. In addition, zinc shows strong seasonal variations in salmoniform fishes (salmons, charrs, and whitefishes have been tested to date). We present case studies of several species, and discuss exciting future directions in this research that is revolutionizing fisheries ecology. ©2003 American Institute of Physics
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36.
  • Limburg, Karin E., et al. (författare)
  • Patterns and magnitude of Zn:Ca in otoliths support the recent phylogenetic typology of Salmoniformes and their sister groups
  • 2010
  • Ingår i: Canadian Journal of Fisheries and Aquatic Sciences. - 1205-7533. ; 67:4, s. 597-604
  • Tidskriftsartikel (refereegranskat)abstract
    • La chimie des otolithes de poissons sert a associer les poissons a des environnements specifiques. La chimie des otolithes peut aussi potentiellement servir d'outil dans la recherche phylogenetique, comme nous le demontrons ici chez les poissons salmonides et les taxons apparentes. Des cartes bidimensionnelles de la chimie de Zn:Ca dans les otolithes montrent des oscillations annuelles d'amplitude chez des membres des salmoniformes (les saumons se distinguant des coregones). Celles-ci se decelent aussi chez les esocides, mais pas de facon marquee chez les osmerides, ni chez les autres taxons moins apparentes. De plus, les amplitudes de Zn:Ca sont maximales chez les salmonides et diminuent chez les autres taxons : salmonides (saumons, ombres et coregones) > esocides > osmerides > autres. Une analyse spatiale sur des cartes en coupe sagittale de Zn:Ca les divise en cinq zones et fournit les moyennes de chaque zone ainsi que les moyennes totales. Une analyse des fonctions discriminantes des differentes zones d'otolithes separe encore mieux les groupes taxonomiques, mais montre que les brochets s'associent de plus pres aux salmonides et les osmerides au groupe externe. L'incorporation de Zn:Ca dans les otolithes peut etre un trait sous controle phylogenetique et la chimie de Zn:Ca des otolithes peut venir appuyer la reorganisation recente de la systematique des salmoniformes et de leurs groupes-soeurs.
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37.
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38.
  • Mentes, Besim, et al. (författare)
  • Chemical speciation of aerosol samples by ion beam thermography
  • 1996
  • Ingår i: Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms. - 0168-583X. ; 109-110, s. 511-518
  • Tidskriftsartikel (refereegranskat)abstract
    • Ion beam thermography (IBT) is a technique for the determination of chemical compounds. The IBT setup combines the multielemental ion beam techniques PIXE, PESA, pNRA and cPESA with thermography. During thermography the temperature is gradually increased up to the order of 600 °C, causing vaporisation of chemical compounds at specific temperatures. The combination of methods display low detection limits over practically the whole periodic table, i.e. PIXE: Z > 13, PESA: C, N, O, pNRA: Li, Be, B, F, Na, Mg, cPESA: H. The analysis is undertaken with an external beam. The thermographic treatment results in a thermogram for each element i.e. the concentration as a function of the temperature of the sample. The chemical compounds are identified by the vaporisation temperature and the stoichiometric relations between the elements vaporised at that temperature. This work deals with technical improvements of the setup and evaluates the dependence on the rate of temperature increase of the vaporisation temperature of chemical compounds. An atmospheric aerosol sample was analysed to demonstrate the capabilities of this combination of IBA methods in atmospheric aerosol research. All major and several minor elements of the sample could be determined, the major inorganic compounds could be speciated and the carbonaceous constituents could be classified according to volatility.
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39.
  • Nilsson, Charlotta, et al. (författare)
  • A nuclear geochemical analysis system for boron quantification using a focused ion beam
  • 2017
  • Ingår i: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 311:1, s. 355-364
  • Tidskriftsartikel (refereegranskat)abstract
    • Ion beam analysis has for decades been used as a tool for geochemical analysis of trace elements using both X-rays (particle induced X-ray emission) and nuclear reaction analysis. With the geoanalytical setup at the Lund Ion Beam Analysis Facility, the boron content in geological samples with a spatial resolution of 1 µm is determined through nuclear reaction analysis. In the newly upgraded setup, a single detector has been replaced by a double sided silicon strip detector with 2048 segments. After optimization, boron content in geological samples as low as 1 µg g−1 can be measured.
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40.
  • Nilsson, Charlotta, et al. (författare)
  • Characterisation of a pre-cell hit detector to be used in single cell irradiation experiments at the Lund Nuclear Microprobe
  • 2008
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - Amsterdam : Elsevier BV. - 0168-583X .- 1872-9584. ; 266:21, s. 4808-4815
  • Tidskriftsartikel (refereegranskat)abstract
    • This paper describes the characterisation of an ultra-thin silicon semicondoctor Delta E detector to be used as a pre-cell ion hit detector in single ion experiments on individual, living cells. The characteristics of interest for this specific application are the hit detection efficiency, which has to be close to 100% to enable bombardment with either a single ion or a counted number of ions, the beam spreading, which should be as small as possible to maintain the targeting accuracy, and the vacuum tightness, since the detector is intended, if possible, to be used simultaneously as vacuum window. The hit detection efficiency was shown to be above 99% when detecting alpha particles or 2 MeV protons, the increase in beam size was about 1 mu m and the vacuum tightness was comparable to that of the Si3N4 wafer which is normally used as vacuum window, thus the Delta E detector fulfils the main criteria to function properly as a single ion hit detector. (C) 2008 Elsevier B.V. All rights reserved.
  •  
41.
  • Nilsson, Charlotta, et al. (författare)
  • Evaluation of a pre-cell hit detector for the future single ion hit facility in Lund
  • 2006
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X .- 1872-9584. ; 249:1-2, s. 924-927
  • Tidskriftsartikel (refereegranskat)abstract
    • Currently, a single ion hit facility, for irradiation of single cells with single, light MeV ions is under development at the Lund Nuclear Microprobe. In this paper, a novel approach to the ion detection issue is presented. A silicon detector, a type utilized at other facilities for post-cell ion detection, has been investigated as a possible option for pre-cell hit detection. If proven successful, this detector could possibly also be used simultaneously as vacuum window. The first experiments carried out on the 9 mu m thick silicon detector, with an area of 4 mm(2), have been aimed at investigations of signal-to-noise ratio and efficiency. The results thus far reveal a low noise level and a noise distribution, which is well separated from the signal peak. However, the efficiency remains a problem, since at present it is far from the required 100%.
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42.
  • Nilsson, E.J.C., et al. (författare)
  • Using microdispensing to manufacture a customized cell dish for microbeam irradiation of single, living cells
  • 2009
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 267:7, s. 1199-1205
  • Tidskriftsartikel (refereegranskat)abstract
    • In this paper is described the preparation of patterned cell dishes to be used in studies of low dose irradiation effects on living cells. Using a droplet microdispenser, an 8 mu m thick polypropylene cell substrate, to which cells do not naturally adhere, was coated in a matrix pattern with the cell adhesive mussel protein Cell-Tak. Cells were shown to adhere and grow on the protein-coated spots, but not on the uncoated parts, providing for guided cell growth. Cultivation of isolated cell colonies provides an opportunity to study how low doses of ionizing radiation affect neighbouring un-irradiated cell colonies. (C) 2009 Elsevier B.V. All rights reserved.
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43.
  • Pallon, Jan, et al. (författare)
  • A new quantitative X-ray system for micro-PIXE analysis
  • 2017
  • Ingår i: X-Ray Spectrometry. - : Wiley. - 0049-8246. ; 46:5, s. 319-324
  • Tidskriftsartikel (refereegranskat)abstract
    • Particle Induced X-ray Emission is a well-established technique for quantitative elemental analysis down to trace levels. During microbeam analysis, where the beam is collimated and focused into a small spot, the beam current reduces to nA or less. The generation of characteristic X-rays is reduced in the same proportion, leading to long data-acquisition times. This can partly be compensated for by using detectors with a large solid angle. In this work, the performance of an annular eight-element silicon drift detector with a total solid angle of 261 msr is described. The initial calibration of the detector was performed using thin elemental standards. Charge measurement was carried out both in a Faraday Cup positioned after the sample and by a pre-sample electrostatic deflection system sampling the beam charge into another Faraday Cup. The two methods were used in parallel and compared during the calibration measurements. A recently installed Versa Module Europe (VME) based data acquisition system equipped with, for example, multi-hit time-to-digital converters, amplifiers, and 32-channel scalers, was used to record data in event-by-event mode for simultaneous data evaluation on multiple computers. Off-line dead time and pile-up corrections were made on the event data that was sorted into spectra and fitted with the GeoPIXE software. The pre-sample deflection charge measurement gave consistent values for the calibration, and this is an important observation implying that non-conductive and thick samples will be able to quantify without the use of internal standards.
  •  
44.
  • Pallon, Jan, et al. (författare)
  • An off-axis STIM procedure for precise mass determination and imaging
  • 2004
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 219-20, s. 988-993
  • Tidskriftsartikel (refereegranskat)abstract
    • For the precise determination of the local mass density in thin samples analysed at the Lund Nuclear Microprobe, a modified version of off-axis STIM is described. An on-axis/off-axis geometry is used where a thin C-foil, placed behind the sample scatters protons into the particle detector. The advantage of this geometry compared to the off-axis case where particles are directly scattered from the sample into the particle detector is that the energy-loss spectrum acquired is less degraded. A spectral resolution comparable to on-axis STIM is achieved at a beam current high enough to allow for a simultaneous PIXE analysis (50-100 pA). (C) 2004 Elsevier B.V. All rights reserved.
  •  
45.
  • Pallon, Jan, et al. (författare)
  • At the Tip of an MeV Beam: Provoking Cells and Performing Tomographic Imaging
  • 2009
  • Ingår i: Acta Physica Polonica A. - 0587-4246. ; 115:2, s. 501-506
  • Konferensbidrag (refereegranskat)abstract
    • Biological applications of ion beams have recently become a new important research field using single ion hit facilities to study individual living cells and their response to the hit of a counted number of ions. One motivation is the search for a better understanding of the fundamental processes taking place in cells and organs as a result of irradiation. Another comes from the increasing interest in using high energy protons and heavy ions as a modality for radiotherapy of deep seated tumours. In the view of treatment efficiency, study of cell culture behaviour under controlled radiation experiments, and in different chemical environments at single ion hit facilities, is a first step towards a better understanding of the processes. Tomographic techniques are applicable to situations where you need information of the inside of an object but do not want to section it into thin slices or cannot do it. Using focused MeV ion beams for tomography restricts the sample size to the order of 10-100 mu m, depending of the initial energy. On the other hand, the ability to focus at a sub-micrometer level makes ion beams well suited for analyses of small sized objects as cells, spores, etc. The scanning transmission ion microscopy mode of tomography gives the mass density and corresponding morphological structure of holes and pores. It can then be used to correct the results from the other mode, particle induced X-ray emission tomography. Here is discussed a porosity analysis of bentonite clay that is planned to form an important buffer zone around canisters filled with spent nuclear reactor fuel waste deposited 500 m underground in Sweden.
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46.
  • Pallon, J., et al. (författare)
  • Ion beam evaluation of silicon carbide membrane structures intended for particle detectors
  • 2016
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section B. - : Elsevier BV. - 0168-583X .- 1872-9584. ; 371, s. 132-136
  • Tidskriftsartikel (refereegranskat)abstract
    • Thin ion transmission detectors can be used as a part of a telescope detector for mass and energy identification but also as a pre-cell detector in a microbeam system for studies of biological effects from single ion hits on individual living cells. We investigated a structure of graphene on silicon carbide (SiC) with the purpose to explore a thin transmission detector with a very low noise level and having mechanical strength to act as a vacuum window. In order to reach very deep cavities in the SiC wafers for the preparation of the membrane in the detector, we have studied the Inductive Coupled Plasma technique to etch deep circular cavities in 325 μm prototype samples. By a special high temperature process the outermost layers of the etched SiC wafers were converted into a highly conductive graphitic layer. The produced cavities were characterized by electron microscopy, optical microscopy and proton energy loss measurements. The average membrane thickness was found to be less than 40 μm, however, with a slightly curved profile. Small spots representing much thinner membrane were also observed and might have an origin in crystal defects or impurities. Proton energy loss measurement (also called Scanning Transmission Ion Microscopy, STIM) is a well suited technique for this thickness range. This work presents the first steps of fabricating a membrane structure of SiC and graphene which may be an attractive approach as a detector due to the combined properties of SiC and graphene in a monolithic materials structure.
  •  
47.
  • Pallon, Jan, et al. (författare)
  • Optimization of PIXE-sensitivity for detection of Ti in thin human skin sections
  • 2005
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 231:1-4, s. 274-279
  • Tidskriftsartikel (refereegranskat)abstract
    • Modern sunscreens contain particles like TiO2 having sizes of 25-70 nm and acting as a reflecting substance. For cosmetic reasons the particle size is minimized. Questions have been raised to what degree these nano particles penetrate the skin barrier, and how they do affect the human. The EU funded project "Quality of skin as a barrier to ultra-fine particles" - NANODERM has started with the purpose to evaluate the possible risks of TiO2 penetration into vital skin layers. The purpose of the work presented here was to find the optimal conditions for micro-PIXE analysis of Ti in thin skin sections. In the skin region where Ti is expected to be found, the naturally occurring major elements phosphorus, chlorine, sulphur and potassium have steep gradients and thus influence the X-ray background in a non-predictable manner. Based on experimental studies of Ti-exposed human skin sections using proton energies ranging from 1.8-2.55 MeV, the corresponding PIXE detection limits for Ti were calculated. The energy that was found to be the most favourable, 1.9 MeV, was then selected for future studies.
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48.
  • Pallon, Jan, et al. (författare)
  • STIM evaluation in GeoPIXE to complement the quantitative dynamic analysis
  • 2009
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 267:12-13, s. 2080-2084
  • Konferensbidrag (refereegranskat)abstract
    • The GeoPIXE software for quantitative PIXE trace element imaging and analysis is a well established package for evaluation of characteristic X-ray data for both PIXE and SXRF. For the case of microbeam applications on semi-thick samples knowledge of the local areal density distribution is important for precise quantification. A technique is reported to achieve this using the measurement of beam particle energy loss as it traverses the sample, as in scanning transmission ion microscopy (STIM). New functionality is added to the GeoPIXE code through integration of routines for STIM sorting of event-by-event data to create elemental maps of the mean energy after traversing the sample. Integration of stopping powers for a given sample matrix then permits the measured energy loss to be related to the local areal density. In a further step, this information is used for X-ray absorption corrections made directly to the PIXE analysis results. As a complement, user-written plugins operating on single STIM spectra have been used to compare the estimated areal density from chosen spots with the corresponding values calculated with the new GeoPIXE routines. The additions made to the code allow a more precise quantification to be done on inhomogeneous, semi-thick samples. (C) 2009 Elsevier B.V. All rights reserved.
  •  
49.
  • Pallon, Jan, et al. (författare)
  • Symbiotic fungi that are essential for plant nutrient uptake investigated with NMP
  • 2007
  • Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 260:1, s. 149-152
  • Tidskriftsartikel (refereegranskat)abstract
    • The nuclear microprobe (NMP) technique using PIXE for elemental analysis and STIM on/off axis for parallel mass density normalization has proven successful to investigate possible interactions between minerals and ectomycorrhizal (EM) mycelia that form symbiotic associations with forest trees. The ability for the EM to make elements biologically available from minerals and soil were compared in field studies and in laboratory experiments, and molecular analysis (PCR-RFLP) was used to identify ectomycorrhizal species from the field samplings. EM rhizomorphs associated with apatite in laboratory systems and in mesh bags incubated in forest ecosystems contained larger amounts of Ca than similar rhizomorphs connected to acid-washed sand. EM mycelium produced in mesh bags had a capacity to mobilize P from apatite-amended sand and a high concentration of K in some rhizomorphs suggests that these fungi are good accumulators of K and may have a significant role in transporting K to trees. Spores formed by arbuscular mycorrhizal (AM) fungi in laboratory cultures were compared with spores formed in saline soils in Tunisia in Northern Africa. We found lower concentrations of P and higher concentrations of Cl in the spores collected from the field than in the spores collected from laboratory cultures. For the case of laboratory cultures, the distribution of e.g. P and K was found to be clearly correlated.
  •  
50.
  • Pédehontaa-Hiaa, Guillaume, et al. (författare)
  • How to detect radionuclides specific to the European Spallation Source in soil samples?
  • 2023
  • Ingår i: Medical Physics in the Baltic States (2023) : Proceedings of the 16th International Conference on Medical Physics - Proceedings of the 16th International Conference on Medical Physics. ; , s. 115-120
  • Konferensbidrag (refereegranskat)abstract
    • The European Spallation Source (ESS) is a neutron research facility under construction in southern Sweden. The facility will produce a wide range of radionuclides including 148Gd, 187W, 172Hf, 182Ta and 178nHf that could be released into the environment in an accident scenario. Detection limits for these contaminants in soil were estimated to be in the mg k-1 range for ICP-MS and <3 Bq per 200 ml soil for gamma-ray spectroscopy.
  •  
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