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Enumeration	Reference	Cover	Find
1.	Gustafsson, U, et al. (author) Compact fiber-optic fluorosensor using a continuous-wave violet diode laser and an integrated spectrometer 2000 In: Review of Scientific Instruments. - : AIP Publishing. - 1089-7623 .- 0034-6748. ; 71:8, s. 3004-3006 Journal article (peer-reviewed)abstract A compact fluorosensor with a fiber-optic measurement probe was developed, employing a continuous-wave violet diode laser as an exciting source and an integrated digital spectrometer for the monitoring of fluorescence signatures. The system has the dimensions 22x13x8 cm(3), and features 5 nm spectral resolution and an excellent detectivity. Results from measurements on vegetation and human premalignant skin lesions are reported, illustrating the potential of the instrument. (C) 2000 American Institute of Physics. [S0034-6748(00)04508-1].
2.	Larsson, Jörgen, et al. (author) Evaluation of laser-irradiated Ar clusters as a source for time-resolved x-ray studies 1999 In: Review of Scientific Instruments. - : AIP Publishing. - 1089-7623 .- 0034-6748. ; 70:5, s. 2253-2256 Journal article (peer-reviewed)abstract We have measured the absolute average photon flux, the spectral characteristics, and the time structure of x rays emitted from Ar clusters which were irradiated by a 100 fs laser with an intensity of 10(17) W/cm(2). The measured photon flux was 10(7) photons per shot in the K-alpha (at 3 keV) line in a 4 pi sr solid angle. The temporal structure was measured using a streak camera with a 10 ps time resolution. It was found that less than 1% of the photons were emitted within the 10 ps time-response function of the streak camera. The emission profile is roughly exponential with a time constant of 3 ns. (C) 1999 American Institute of Physics. [S0034-6748(99)03605-9].
3.	Yakimov, V, et al. (author) Electrostatic force-feedback force sensor incorporated in an ultrahigh vacuum force microscope 2000 In: Review of Scientific Instruments. - 0034-6748 .- 1089-7623. ; 71:1, s. 133-136 Journal article (peer-reviewed)abstract A force sensor based on a fiber-optic interferometric displacement transducer incorporated in an ultrahigh vacuum atomic force microscope is described. The operation of the sensor is based on balancing the tip-sample interfacial force using an electrostatic actuator. The electrodes of the actuator are formed by the grounded W cantilever and the metallized end facet of the optical fiber used by the interferometer. Chemical reduction of Ag by a wet chemical method is used for metal coating of the fiber end. A special masking procedure is used to obtain a window hole in the metal coating at the position of the fiber core to allow for optical beam output. Using a window instead of a semitransparent metal film allows us to save the low-finesse characteristics of the interferometer which facilitates the calibration of cantilever displacement. The performance of the sensor is discussed and exemplified by experimental results from force-separation measurements on the W-Au system in ultrahigh vacuum. (C) 2000 American Institute of Physics. [S0034-6748(00)01401-5].
4.	Johansen, K, et al. (author) Imaging surface plasmon resonance sensor based on multiple wavelengths : Sensitivity considerations 2000 In: Review of Scientific Instruments. - 0034-6748 .- 1089-7623. ; 71:9, s. 3530-3538 Journal article (peer-reviewed)abstract A new, multiple wavelength surface plasmon resonance apparatus for imaging applications is presented. It can be used for biosensing, e.g., for monitoring of chemical and biological reactions in real time with label-free molecules. A setup with a fixed incident angle in the Kretschmann configuration with gold as the supporting metal is described, both theoretically and experimentally. Simulations of the sensor response based on independently recorded optical (ellipsometric) data of gold show that the sensitivity for three-dimensional recognition layers (bulk) increases with increasing wavelength. For two-dimensional recognition layers (adlayer) maximum sensitivity is obtained within a limited wavelength range. In this situation, the rejection of bulk disturbances, e.g., emanating from temperature variations, decreases, with increasing wavelength. For imaging surface plasmon resonance the spatial resolution decreases with increasing wavelength. Hence, there is always a compromise between spatial resolution, bulk disturbance rejection, and sensitivity. Most importantly, by simultaneously using multiple wavelengths, it is possible to maintain a high sensitivity and accuracy over a large dynamic range. Furthermore, our simulations show that the sensitivity is independent of the refractive index of the prism. (C) 2000 American Institute of Physics. [S0034-6748(00)02909-9].
5.	Johansson, M, et al. (author) An equipment for three-dimensional spatially resolved gas analysis 2000 In: Review of Scientific Instruments. - 0034-6748 .- 1089-7623. ; 71:9, s. 3513-3521 Journal article (peer-reviewed)abstract The apparatus described is able to measure three-dimensional temperature and partial pressure distributions in gas mixtures with a spatial resolution better than 0.5 mm. The measurements are performed in a well defined laminar gas flow in a duct of rectangular cross section. The gas mixture is sampled locally with a quartz tube orifice leak movable in three dimensions. Mass spectrometry is used for partial pressure measurements. The total pressure in the duct can be regulated in the range 50-760 Torr and the gas temperature can be varied between room temperature and 500 degrees C. The apparatus is primarily designed for studies of the distribution of reactants and products over catalytic surfaces. Because of the well defined gas flow in the duct the partial pressure distributions of reactants and products over the catalytic surface can be calculated with good accuracy. By comparing calculated pressure distributions to measured ones the local reaction rate on the catalytic surface as well as the pressures of reactants and products at the surface can be obtained. As an example it is shown how the hydrogen distribution over a platinum surface exposed to a mixture of hydrogen, oxygen, and argon can be used to calculate the local water formation rate on the platinum surface. (C) 2000 American Institute of Physics. [S0034-6748(00)01409-X].
6.	af Klinteberg, C, et al. (author) Compact medical fluorosensor for minimally invasive tissue characterization 2005 In: Review of Scientific Instruments. - : AIP Publishing. - 1089-7623 .- 0034-6748. ; 76:3 Journal article (peer-reviewed)abstract A compact fiber-optic point-measuring fluorosensor fully adapted to clinical studies is described. The system can use two excitation wavelengths, 337 and 405 nm, obtained from a nitrogen laser directly, or after dye laser conversion, respectively. The image intensifier used in the spectrometer can be gated with a variable time delay, allowing also time-resolved spectra to be extracted, with a time resolution of about 4 ns. Moreover, diffusely scattered white light can be spectrally recorded. The system is fully computer controlled enabling short recording times in clinical application, which are illustrated.
7.	Aksela, S., et al. (author) Study of different SX-700 monochromator designs for the undulator beamline (BL51) at MAX-lab 1992 In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 63:1, s. 1252-1255 Journal article (peer-reviewed)abstract Different designs of the SX-700 plane grating monochromator have been investigated for the undulator beamline (51) by using analytical considerations and carrying out ray tracing calculations. The most important modifications of the original design are those where the ellipsoidal focusing mirror has been replaced by a plane elliptical or by a spherical mirror. A significant advantage of the spherical mirror is essentially better figure accuracies (±0.2 arcsec). This is partly compensated by the introduced coma aberration which, however, can be made small with rather long exit arm lengths (5-6 m). If the slope errors of the plane elliptical mirror can be made as small as 0.5 arcsec, the differences in the ultimate resolution are small between the plane elliptical and spherical designs and then the source size is the main factor.
8.	Alm, Ove, et al. (author) A multiple coaxial wire for pressure calibration 1974 In: Review of Scientific Instruments. - : American Institute of Physics (AIP). - 0034-6748 .- 1089-7623. ; 45:4, s. 594-595 Journal article (peer-reviewed)abstract A single wire containing several metals suitable for pressure calibration has been produced by extrusion. Coaxial combinations of Ce-Bi-TI and Ce-Bi-Ba have been prepared by the procedure described.
9.	Alvarez-Asencio, Ruben, et al. (author) Note : Determination of torsional spring constant of atomic force microscopy cantilevers: Combining normal spring constant and classical beam theory (vol 84, 096102, 2013) 2014 In: Review of Scientific Instruments. - : AMER INST PHYSICS. - 0034-6748 .- 1089-7623. ; 85:7 Journal article (peer-reviewed)
10.	Álvarez-Asencio, Ruben, et al. (author) Note : Determination of torsional spring constant of atomic force microscopy cantilevers: Combining normal spring constant and classical beam theory 2013 In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 84:9 Journal article (peer-reviewed)abstract A technique has been developed for the calculation of torsional spring constants for AFM cantilevers based on the combination of the normal spring constant and plate/beam theory. It is easy to apply and allow the determination of torsional constants for stiff cantilevers where the thermal power spectrum is difficult to obtain due to the high resonance frequency and low signal/noise ratio. The applicability is shown to be general and this simple approach can thus be used to obtain torsional constants for any beam shaped cantilever.
11.	Amann, Peter, et al. (author) A high-pressure x-ray photoelectron spectroscopy instrument for studies of industrially relevant catalytic reactions at pressures of several bars 2019 In: Review of Scientific Instruments. - : American Institute of Physics (AIP). - 0034-6748 .- 1089-7623. ; 90:10 Journal article (peer-reviewed)abstract We present a new high-pressure x-ray photoelectron spectroscopy system dedicated to probing catalytic reactions under realistic conditions at pressures of multiple bars. The instrument builds around the novel concept of a "virtual cell" in which a gas flow onto the sample surface creates a localized high-pressure pillow. This allows the instrument to be operated with a low pressure of a few millibar in the main chamber, while simultaneously a local pressure exceeding 1 bar can be supplied at the sample surface. Synchrotron based hard x-ray excitation is used to increase the electron mean free path in the gas region between sample and analyzer while grazing incidence <5 degrees close to total external refection conditions enhances surface sensitivity. The aperture separating the high-pressure region from the differential pumping of the electron spectrometer consists of multiple, evenly spaced, micrometer sized holes matching the footprint of the x-ray beam on the sample. The resulting signal is highly dependent on the sample-to-aperture distance because photoemitted electrons are subject to strong scattering in the gas phase. Therefore, high precision control of the sample-to-aperture distance is crucial. A fully integrated manipulator allows for sample movement with step sizes of 10 nm between 0 and -5 mm with very low vibrational amplitude and also for sample heating up to 500 degrees C under reaction conditions. We demonstrate the performance of this novel instrument with bulk 2p spectra of a copper single crystal at He pressures of up to 2.5 bars and C1s spectra measured in gas mixtures of CO + H-2 at pressures of up to 790 mbar. The capability to detect emitted photoelectrons at several bars opens the prospect for studies of catalytic reactions under industrially relevant operando conditions.
12.	Amole, C., et al. (author) Autoresonant-spectrometric determination of the residual gas composition in the ALPHA experiment apparatus 2013 In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 84:6, s. 065110- Journal article (peer-reviewed)abstract Knowledge of the residual gas composition in the ALPHA experiment apparatus is important in our studies of antihydrogen and nonneutral plasmas. A technique based on autoresonant ion extraction from an electrostatic potential well has been developed that enables the study of the vacuum in our trap. Computer simulations allow an interpretation of our measurements and provide the residual gas composition under operating conditions typical of those used in experiments to produce, trap, and study antihydrogen. The methods developed may also be applicable in a range of atomic and molecular trap experiments where Penning-Malmberg traps are used and where access is limited.
13.	Andersson, Mats, et al. (author) Flexible lock-in detection system based on synchronized computer plug-in boards applied in sensitive gas spectroscopy 2007 In: Review of Scientific Instruments. - : AIP Publishing. - 1089-7623 .- 0034-6748. ; 78:11 Journal article (peer-reviewed)abstract We present a flexible and compact, digital, lock-in detection system and its use in high-resolution tunable diode laser spectroscopy. The system involves coherent sampling, and is based on the synchronization of two data acquisition cards running on a single standard computer. A software-controlled arbitrary waveform generator is used for laser modulation, and a four-channel analog/digital board records detector signals. Gas spectroscopy is performed in the wavelength modulation regime. The coherently detected signal is averaged a selected number of times before it is stored or analyzed by software-based, lock-in techniques. Multiple harmonics of the modulation signal 1f, 2f, 3f, 4f, etc. are available in each single data set. The sensitivity is of the order of 10−5, being limited by interference fringes in the measurement setup. The capabilities of the system are demonstrated by measurements of molecular oxygen in ambient air, as well as dispersed gas in scattering materials, such as plants and human tissue.
14.	Andersson, M., et al. (author) Using optical tweezers for measuring the interaction forces between human bone cells and implant surfaces: System design and force calibration 2007 In: Rev Sci Instrum. - : AIP Publishing. ; 78:7 Journal article (peer-reviewed)abstract Optical tweezers were used to study the interaction and attachment of human bone cells to various types of medical implant materials. Ideally, the implant should facilitate cell attachment and promote migration of the progenitor cells in order to decrease the healing time. It is therefore of interest, in a controlled manner, to be able to monitor the cell adhesion process. Results from such studies would help foresee the clinical outcome of integrating medical implants. The interactions between two primary cell culture models, human gingival fibroblasts and bone forming human osteoblast cells, and three different implant materials, glass, titanium, and hydroxyapatite, were studied. A novel type of optical tweezers, which has a newly designed quadrant detector and a powerful 3 W laser was constructed and force calibrated using two different methods: one method in which the stiffness of the optical trap was obtained by monitoring the phase lag between the trap and the moved object when imposing a forced oscillation on the trapped object and another method in which the maximum trapping force was derived from the critical velocity at which the object escapes the trap. Polystyrene beads as well as cells were utilized for the calibrations. This is the first time that cells have been used directly for these types of force calibrations and, hence, direct measurements of forces exerted on cells can be performed, thus avoiding the difficulties often encountered when translating the results obtained from cell measurements to the calibrations obtained with reference materials. This more straightforward approach represents an advantage in comparison to established methods.
15.	Andersson, Odd E., et al. (author) Low temperature calibration of Manganin pressure gauges 1997 In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 68:2, s. 1344-1345 Journal article (peer-reviewed)abstract High pressures are often measured using the resistance of Manganin wires. However, the pressure coefficient of resistance is known to depend on temperature. We have measured this temperature dependence by comparing the output from a Manganin gauge with that of a well calibrated Zeranin gauge and determined a correction factor which enables us to measure the pressure at any temperature between 150 and 300 K with a temperature dependent error well below 0.5%.
16.	Andersson, Peter, 1981-, et al. (author) Correction for dynamic bias error in transmission measurements of void fraction 2012 In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 83:12, s. 125110- Journal article (peer-reviewed)abstract Dynamic bias errors occur in transmission measurements, such as X-ray, gamma, or neutron radiography or tomography. This is observed when the properties of the object are not stationary in time and its average properties are assessed. The nonlinear measurement response to changes in transmission within the time scale of the measurement implies a bias, which can be difficult to correct for. A typical example is the tomographic or radiographic mapping of void content in dynamic two-phase flow systems. In this work, the dynamic bias error is described and a method to make a first-order correction is derived. A prerequisite for this method is variance estimates of the system dynamics, which can be obtained using high-speed, time-resolved data acquisition. However, in the absence of such acquisition, a priori knowledge might be used to substitute the time resolved data. Using synthetic data, a void fraction measurement case study has been simulated to demonstrate the performance of the suggested method. The transmission length of the radiation in the object under study and the type of fluctuation of the void fraction have been varied. Significant decreases in the dynamic bias error were achieved to the expense of marginal decreases in precision.
17.	Andersson, Per, et al. (author) Electrical resistance of Evanohm under pressure 1975 In: Review of Scientific Instruments. - : American Institute of Physics (AIP). - 0034-6748 .- 1089-7623. ; 46:9, s. 1292-1293 Journal article (peer-reviewed)abstract The electrical resistance of Evanohm wire has been determined as a function of hydrostatic pressure. A Teflon cell with a novel type of electrical feedthrough was used to contain the fluid medium. The resistance was found to decrease approximately linearly by 0.3% up to 27 kilobar. The remarkably small variation of its resistance with temperature and pressure makes Evanohm a suitable material for strain measurements under pressure.
18.	Andersson, Peter, 1981-, et al. (author) Neutron tomography of axially symmetric objects using 14 MeV neutrons from a portable neutron generator 2014 In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 85:8, s. 085109- Journal article (peer-reviewed)abstract In nuclear boiling water reactor cores, the distribution of water and steam (void) is essential for both safety and efficiency reasons. In order to enhance predictive capabilities, void distribution assessment is performed in two-phase test-loops under reactor-relevant conditions. This article proposes the novel technique of fast-neutron tomography using a portable deuterium-tritium neutron generator to determine the void distribution in these loops.Fast neutrons have the advantage of high transmission through the metallic structures and pipes typically concealing a thermal-hydraulic test loop, while still being fairly sensitive to the water/void content. However, commercially available fast-neutron generators also have the disadvantage of a relatively low yield and fast-neutron detection also suffers from relatively low detection efficiency. Fortunately, some loops are axially symmetric, a property which can be exploited to reduce the amount of data needed for tomographic measurement, thus limiting the interrogation time needed.In this article, three axially-symmetric test objects depicting a thermal-hydraulic test loop have been examined; steel pipes with outer diameter 24 mm, thickness 1.5 mm and with three different distributions of the plastic material POM inside the pipes. Data recorded with the FANTOM fast-neutron tomography instrument have been used to perform tomographic reconstructions to assess their radial material distribution. Here, a dedicated tomographic algorithm that exploits the symmetry of these objects has been applied, which is described in the paper.Results are demonstrated in 20 rixel (radial pixel) reconstructions of the interior constitution and 2D visualization of the pipe interior is demonstrated. The local POM attenuation coefficients in the rixels were measured with errors (RMS) of 0.025, 0.020 and 0.022 cm-1, solid POM attenuation coefficient. The accuracy and precision is high enough to provide a useful indication on the flow mode, and a visualization of the radial material distribution can be obtained. A benefit of this system is its potential to be mounted at any axial height of a two-phase test section without requirements for pre-fabricated entrances or windows. This could mean a significant increase in flexibility of the void distribution assessment capability at many existing two-phase test loops.
19.	Andersson, Per, et al. (author) Thermal conductivity of solids under pressure by the transient hot wire method 1976 In: Review of Scientific Instruments. - : American Institute of Physics (AIP). - 0034-6748 .- 1089-7623. ; 47:2, s. 205-209 Journal article (peer-reviewed)abstract An electronic circuit has been constructed which delivers constant power to a nickel wire also functioning as a resistance thermometer. The temperature increase versus time, t, is linear in ln t, and the coefficient of slope directly yields the thermal conductivity of the medium surrounding the wire. Systematic errors due to finite time, wire length, and lateral extension of the medium and due to plastic deformation of the wire are analyzed. Temperatures are sampled automatically, and the digital data are reduced by means of an on-line desk calculator. The thermal conductivities of AgCl and polytetrafluoroethylene have been measured up to 10 kilobar.
20.	Andersson, Patrik U, 1970, et al. (author) Efficient source for the production of ultradense deuterium D(-1) for laser-induced fusion (ICF) 2011 In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 82 Journal article (peer-reviewed)abstract A novel source which simplifies the study of ultradense deuterium D(-1) is now described. This means one step further toward deuterium fusion energy production. The source uses internal gas feed and D(-1) can now be studied without time-of-flight spectral overlap from the related dense phase D(1). The main aim here is to understand the material production parameters, and thus a relatively weak laser with focused intensity ≤1012 W cm−2 is employed for analyzing the D(-1) material. The properties of the D(-1) material at the source are studied as a function of laser focus position outside the emitter, deuterium gas feed, laser pulse repetition frequency and laser power, and temperature of the source. These parameters influence the D(-1) cluster size, the ionization mode, and the laser fragmentation patterns.
21.	Andersson, Staffan, et al. (author) Techniques for determining thermal conductivity and heat capacity under hydrostatic pressure 1986 In: Review of Scientific Instruments. - : American Institute of Physics (AIP). - 0034-6748 .- 1089-7623. ; 57:8, s. 1633-1639 Journal article (peer-reviewed)abstract The paper describes a method for measuring the pressure dependence of the thermal conductivity and the heat capacity of hard materials and single crystals. Two parallel metal strips are evaporated onto a flat surface of the specimen, one being used as a heater, the other as a resistance thermometer. The appropriate theoretical expression for a specimen in a liquid medium is fitted to the temperature, sampled at constant time intervals. The thermophysical properties of the liquid high‐pressure medium are taken from hot‐wire experiments. The procedure has been thoroughly tested at atmospheric pressure using an MgO crystal and glass as specimens and liquids of different characteristics in lieu of high‐pressure medium. The accuracy attainable was found to be 3% or better, the standard deviation of the measurements being about 0.3%. The potential of the system was demonstrated by measurements on single‐crystal MgO under pressures up to 1 GPa.
22.	Andersson, Å, et al. (author) The new 1.5 GeV storage ring for synchrotron radiation : MAX II 1995 In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 66:2, s. 1850-1853 Journal article (peer-reviewed)abstract The MAX laboratory at Lund University, Sweden, today operates an accelerator system consisting of a 100 MeV racetrack microtron and a 550 MeV storage ring (MAX I). At the moment (July 1994) a new storage ring MAX II is near completion and will start first injections within 2 months. This work gives an overview of the MAX II project including the first beamlines and a description of the accelerator system. MAX II is a 1.5 GeV third generation light source optimized for the VUV and soft-x-ray region. It consists of a ten cell double bend achromat lattice forming the 90 m circumference ring. Injection is done at 500 MeV from the existing storage ring MAX I, and ramping up to full energy will take place in MAX II. The straight sections have a length of 3.2 m and eight sections are free to house insertion devices. At start up the ring will be equipped with one 7.5 T superconducting wiggler and one 1.8 T multipole wiggler. Two more undulators are ordered and under construction. To be able to achieve the project a few shortcuts have been made in the design of the storage ring: (1) Nonzero dispersion is allowed in the straight sections, (2) chromaticity correction is built into the quadrupole magnets, and (3) the length of the straight sections is limited to 3.2 m. The project is progressing on time. Extraction of an electron beam from the MAX I storage ring has been achieved and has successfully been transported into the MAX II building. The MAX II ring is under assembly with most of the sections already mounted. First injection is planned to take place in August 1994.
23.	Arnalds, U. B., et al. (author) A magnetron sputtering system for the preparation of patterned thin films and in situ thin film electrical resistance measurements 2007 In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 78:10, s. 103901- Journal article (peer-reviewed)abstract We describe a versatile three gun magnetron sputtering system with a custom made sample holder for in situ electrical resistance measurements, both during film growth and ambient changes on film electrical properties. The sample holder allows for the preparation of patterned thin film structures, using up to five different shadow masks without breaking vacuum. We show how the system is used to monitor the electrical resistance of thin metallic films during growth and to study the thermodynamics of hydrogen uptake in metallic thin films. Furthermore, we demonstrate the growth of thin film capacitors, where patterned films are created using shadow masks.
24.	Artemiev, A, et al. (author) X-ray parabolic lenses made from glassy carbon by means of laser 2006 In: Review of Scientific Instruments. - : AIP Publishing. - 1089-7623 .- 0034-6748. ; 77:6 Journal article (peer-reviewed)abstract Parabolic planar compound refractive lenses (CRLs) made from glassy carbon by means of laser ablation are presented. They have radii of curvatures of 5 and 200 mu m and geometric apertures of 40 and 900 mu m, respectively. The numbers of biconcave elements in the CRLs were 4, 7, and 200. The planar lenses allow formation of a linear focus of length comparable with the depths of their profiles. Usage of two CRLs in a crossed geometry provides formation of two-dimensional focus. The lenses were tested at the European Synchrotron Radiation Facility at the bending magnet beam line BM-5. The minimum experimental size of the focus has been achieved as 1.4 mu m.
25.	Assefa, T. A., et al. (author) The fluctuation–dissipation measurement instrument at the Linac Coherent Light Source 2022 In: Review of Scientific Instruments. - : AIP Publishing. - 1089-7623 .- 0034-6748. ; 93 Journal article (peer-reviewed)abstract The development of new modes at x-ray free electron lasers has inspired novel methods for studying fluctuations at different energies and timescales. For closely spaced x-ray pulses that can be varied on ultrafast time scales, we have constructed a pair of advanced instruments to conduct studies targeting quantum materials. We first describe a prototype instrument built to test the proof-of-principle of resonant magnetic scattering using ultrafast pulse pairs. This is followed by a description of a new endstation, the so-called fluctuation–dissipation measurement instrument, which was used to carry out studies with a fast area detector. In addition, we describe various types of diagnostics for single-shot contrast measurements, which can be used to normalize data on a pulse-by-pulse basis and calibrate pulse amplitude ratios, both of which are important for the study of fluctuations in materials. Furthermore, we present some new results using the instrument that demonstrates access to higher momentum resolution.
26.	Attard, P, et al. (author) Dynamic surface force measurement. I. van der Waals collisions 1999 In: Review of Scientific Instruments. - 0034-6748 .- 1089-7623. ; 69, s. 3852-3866 Journal article (peer-reviewed)abstract Theoretical calculations and experimental measurements are used to show that hitherto neglected inertial effects can be significant in computer- controlled surface force measurement devices such as the atomic force microscope. The problem is analyzed in detail for the case of the van der Waals attraction in air. It is demonstrated that equating the cantilever deflection to the surface force systematically underestimates the magnitude of the surface force, increasingly so as the speed of approach is increased. It is also shown that the surface separation becomes lost at high accelerations due to a dynamic uncoupling of the cantilever deflection and angle. The effects of elastic deformation of the bodies are taken into account, including the collision-induced elastic vibrations in the solids. Experimental data are obtained for the van der Waals attraction and collision of glass surfaces in air using the measurement and analysis of surface forces device. All of the effects found in the theoretical calculations are identified in the experimental data.
27.	Attard, Phil, et al. (author) Thermal calibration of photodiode sensitivity for atomic force microscopy 2006 In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 77:11 Journal article (peer-reviewed)abstract The photodiode sensitivity in the atomic force microscope is calibrated by relating the voltage noise to the thermal fluctuations of the cantilever angle. The method accounts for the ratio of the thermal fluctuations measured in the fundamental vibration mode to the total, and also for the tilt and extended tip of the cantilever. The method is noncontact and is suitable for soft or deformable surfaces where the constant compliance method cannot be used. For hard surfaces, the method can also be used to calibrate the cantilever spring constant.
28.	Azzouz, Hatim, et al. (author) Capacitive readout and gating of superconducting single photon detectors 2013 In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 84:5 Journal article (peer-reviewed)abstract We propose and develop a readout scheme for superconducting single-photon detectors based on an integrated circuit, relaxing the need for large bandwidth amplification and resulting in voltage steps proportional to the number of detected photons. We also demonstrate time gating, to filter scattered light in time and reduce dark counts. This could lead to a higher signal-to-noise ratio. The gate pulse is generated on the detection of a photon created by a spontaneous parametric down-conversion source, heralding the presence of a second photon. These two schemes could find applications within advanced multi-array imaging detection systems.
29.	Backlin, Eric (author) A comparator for spectroscopic work 1930 In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 1:11, s. 662-666 Journal article (peer-reviewed)
30.	Banuazizi, Seyed Amir Hossein, et al. (author) Microwave probe stations with three-dimensional control of the magnetic field to study high frequency dynamics in nanoscale devices 2018 In: Review of Scientific Instruments. - 0034-6748 .- 1089-7623. Journal article (peer-reviewed)abstract We present two microwave probe stations with motorized rotary stages for adjusting the magnitude and angle of the applied magnetic field. In the first system, the magnetic field is provided by an electromagnet and can be adjusted from 0 to ~ 1.4 T while its polar angle (θ) can be varied from 0o to 360o. In the second system the magnetic field is provided by a Halbach array permanent magnet, which can be rotated and translated to cover the full range of polar (θ) and azimuthal (φ) angles with a tunable field magnitude up to ~ 1 T. Both systems are equipped with microwave probes, bias-Ts, amplifiers, and spectrum analyzers, to allow for microwave characterization up to 40 GHz, as well as software to automatically perform continuous large sets of electrical and microwave measurements.
31.	Banuazizi, S. Amir Hossein, et al. (author) Microwave probe stations with throw-dimensional control of the magnetic field to study high-frequency dynamic in nanoscale devices 2018 In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 89:6 Journal article (peer-reviewed)abstract We present two microwave probe stations with motorized rotary stages for adjusting the magnitude and angle of the applied magnetic field. In the first system, the magnetic field is provided by an electromagnet and can be adjusted from 0 to similar to 1.4 T while its polar angle (theta) can be varied from 0 degrees to 360 degrees. In the second system the magnetic field is provided by a Halbach array permanent magnet, which can be rotated and translated to cover the full range of polar (theta) and azimuthal (phi) angles with a tunable field magnitude up to similar to 1 T. Both systems are equipped with microwave probes, bias-Ts, amplifiers, and spectrum analyzers, to allow for microwave characterization up to 40 GHz, as well as software to automatically perform continuous large sets of electrical and microwave measurements. Published by AIP Publishing.
32.	Barton, C., et al. (author) Status of the Phoenix electron cyclotron charge breeder at ISOLDE, CERN 2008 In: Review of Scientific Instruments. - : AIP Publishing. - 1089-7623 .- 0034-6748. ; 79 Journal article (peer-reviewed)abstract We report here on the last progresses made with the PHOENIX electron cyclotron resonance charge breeder test bench at ISOLDE. Recently, an experiment was performed to test the trapping of 61Fe daughter nuclides from the decay of 61Mn nuclides. Preliminary results are given.
33.	Batistoni, Paola, et al. (author) Calibration of neutron detectors on the Joint European Torus 2017 In: Review of Scientific Instruments. - : AMER INST PHYSICS. - 0034-6748 .- 1089-7623. ; 88:10 Journal article (peer-reviewed)abstract The present paper describes the findings of the calibration of the neutron yield monitors on the Joint European Torus (JET) performed in 2013 using a Cf-252 source deployed inside the torus by the remote handling system, with particular regard to the calibration of fission chambers which provide the time resolved neutron yield from JET plasmas. The experimental data obtained in toroidal, radial, and vertical scans are presented. These data are first analysed following an analytical approach adopted in the previous neutron calibrations at JET. In this way, a calibration function for the volumetric plasma source is derived which allows us to understand the importance of the different plasma regions and of different spatial profiles of neutron emissivity on fission chamber response. Neutronics analyses have also been performed to calculate the correction factors needed to derive the plasma calibration factors taking into account the different energy spectrum and angular emission distribution of the calibrating (point) Cf-252 source, the discrete positions compared to the plasma volumetric source, and the calibration circumstances. All correction factors are presented and discussed. We discuss also the lessons learnt which are the basis for the on-going 14 MeV neutron calibration at JET and for ITER.
34.	Behm, K. T., et al. (author) A spectrometer for ultrashort gamma-ray pulses with photon energies greater than 10 MeV 2018 In: Review of Scientific Instruments. - : AIP Publishing. - 1089-7623 .- 0034-6748. ; 89:11 Journal article (peer-reviewed)abstract © 2018 Author(s). We present a design for a pixelated scintillator based gamma-ray spectrometer for non-linear inverse Compton scattering experiments. By colliding a laser wakefield accelerated electron beam with a tightly focused, intense laser pulse, gamma-ray photons up to 100 MeV energies and with few femtosecond duration may be produced. To measure the energy spectrum and angular distribution, a 33 × 47 array of cesium-iodide crystals was oriented such that the 47 crystal length axis was parallel to the gamma-ray beam and the 33 crystal length axis was oriented in the vertical direction. Using an iterative deconvolution method similar to the YOGI code, modeling of the scintillator response using GEANT4 and fitting to a quantum Monte Carlo calculated photon spectrum, we are able to extract the gamma ray spectra generated by the inverse Compton interaction.
35.	Belova, Liubov M., et al. (author) Rapid preparation of electron beam induced deposition Co magnetic force microscopy tips with 10 nm spatial resolution 2012 In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 83:9, s. 093711- Journal article (peer-reviewed)abstract Magnetic force microscope Co spike tips with lateral magnetic resolution of 10 nm have been prepared. The Co spikes are grown by electron beam induced deposition of Co from Co-2(CO)(8) gas precursor. The high resolution Co spikes are fabricated at the spot of a tightly focused electron beam on the tip of commercial atomic force microscope cantilevers. Qualitative investigations indicate that a spike grown on a planar base of Co improves the signal to noise.
36.	Belyayev, S. M., et al. (author) Minimization of nanosatellite low frequency magnetic fields 2016 In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 87:3 Journal article (peer-reviewed)abstract Small weight and dimensions of the micro- and nanosatellites constrain researchers to place electromagnetic sensors on short booms or on the satellite body. Therefore the electromagnetic cleanliness of such satellites becomes a central question. This paper describes the theoretical base and practical techniques for determining the parameters of DC and very low frequency magnetic interference sources. One of such sources is satellite magnetization, the reduction of which improves the accuracy and stability of the attitude control system. We present design solutions for magnetically clean spacecraft, testing equipment, and technology for magnetic moment measurements, which are more convenient, efficient, and accurate than the conventional ones. (C) 2016 AIP Publishing LLC.
37.	Bengtsson, Lars, 1963 (author) A microcontroller-based lock-in amplifier for sub-milliohm resistance measurements 2012 In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 83:7 Journal article (peer-reviewed)abstract This paper presents a novel approach to the design of a digital ohmmeter with a resolution of <60 μΩ based on a general-purpose microcontroller and a high-impedance instrumentation amplifier only. The design uses two digital I/O-pins to alternate the current through the sample resistor and combined with a proper firmware routine, the design is a lock-in detector that discriminates any signal that is out of phase/frequency with the reference signal. This makes it possible to selectively detect the μV drop across sample resistors down to 55.6 μΩ using only the current that can be supplied by the digital output pins of a microcontroller. This is achieved without the need for an external reference signal generator and does not rely on the computing processing power of a digital signal processor.
38.	Bengtsson, Lars, 1963 (author) Implementation of high-resolution time-to-digital converter in 8-bit microcontrollers 2012 In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 83:article no. 045107 Journal article (peer-reviewed)abstract This paper will demonstrate how a time-to-digital converter (TDC) with sub-nanosecond resolution can be implemented into an 8-bit microcontroller using so called “direct” methods. This means that a TDC is created using only five bidirectional digital input–output-pins of a microcontroller and a few passive components (two resistors, a capacitor, and a diode). We will demonstrate how a TDC for the range 1–10 μs is implemented with 0.17 ns resolution. This work will also show how to linearize the output by combining look-up tables and interpolation.
39.	Bernard, J., et al. (author) A ""tabletop"" electrostatic ion storage ring : Mini-Ring 2008 In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 79:7, s. 75109- Journal article (peer-reviewed)abstract We report on the design, construction, and commissioning of a novel electrostatic ion storage ring of small dimensions-in the following referred to as ""Mini-Ring."" Mini-Ring consists of four horizontal parallel-plate deflectors and two conical electrostatic mirrors. Ions are injected through the two deflectors on the injection side and off axis with respect to the conical mirrors which face each other. The first injection deflector, originally at zero voltage, is switched to its set value such that the ions after one turn follow stable trajectories of lengths of roughly 30 cm. This design reduces the number of electrodes necessary to guide the ion beam through the ring in stable orbits. The six elements (deflectors and mirrors) are placed on a common grounded plate-the tabletop. Here, we present the design, ion trajectory simulations, and results of the first test experiments demonstrating the successful room-temperature operation of Mini-Ring at background pressures of 10(-6)-10(-7) mbar.
40.	Bernardo, J., et al. (author) Ion temperature and toroidal rotation in JET's low torque plasmas 2016 In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 87:11 Journal article (peer-reviewed)abstract This paper reports on the procedure developed as the best method to provide an accurate and reliable estimation of the ion temperature T-i and the toroidal velocity v(phi) from Charge-eXchange Recombination Spectroscopy (CXRS) data from intrinsic rotation experiments at the Joint European Torus with the carbon wall. The low impurity content observed in such plasmas, resulting in low active CXRS signal, alongside low Doppler shifts makes the determination of Ti and v(phi) particularly difficult. The beam modulation method will be discussed along with the measures taken to increase photon statistics and minimise errors from the absolute calibration and magneto-hydro-dynamics effects that may impact the CXRS passive emission.
41.	Berntsen, Magnus H., et al. (author) A spin- and angle-resolving photoelectron spectrometer 2010 In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 81:3 Journal article (peer-reviewed)abstract A new type of hemispherical electron energy analyzer that permits angle and spin resolved photoelectron spectroscopy has been developed. The analyzer permits standard angle resolved spectra to be recorded with a two-dimensional detector in parallel with spin detection using a mini-Mott polarimeter. General design considerations as well as technical solutions are discussed and test results from the Au(111) surface state are presented.
42.	Berntsen, Magnus H., et al. (author) An experimental setup for high resolution 10.5 eV laser-based angle-resolved photoelectron spectroscopy using a time-of-flight electron analyzer 2011 In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 82:9, s. 095113- Journal article (peer-reviewed)abstract We present an experimental setup for laser-based angle-resolved time-of-flight photoemission. Using a picosecond pulsed laser, photons of energy 10.5 eV are generated through higher harmonic generation in xenon. The high repetition rate of the light source, variable between 0.2 and 8 MHz, enables high photoelectron count rates and short acquisition times. By using a time-of-flight analyzer with angle-resolving capabilities, electrons emitted from the sample within a circular cone of up to +/- 15 degrees can be collected. Hence, simultaneous acquisition of photoemission data for a complete area of the Brillouin zone is possible. The current photon energy enables bulk sensitive measurements, high angular resolution, and the resulting covered momentum space is large enough to enclose the entire Brillouin zone in cuprate high-T(c) superconductors. Fermi edge measurements on polycrystalline Au shows an energy resolution better than 5 meV. Data from a test measurement of the Au(111) surface state are presented along with measurements of the Fermi surface of the high-T(c) superconductor Bi(2)Sr(2)CaCu(2)O(8+delta) (Bi2212).
43.	Berntsen, Peter, 1974, et al. (author) The serial millisecond crystallography instrument at the Australian Synchrotron incorporating the "Lipidico" injector 2019 In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 90:8 Journal article (peer-reviewed)abstract A serial millisecond crystallography (SMX) facility has recently been implemented at the macromolecular crystallography beamline, MX2 at the Australian Synchrotron. The setup utilizes a combination of an EIGER X 16M detector system and an in-house developed high-viscosity injector, "Lipidico." Lipidico uses a syringe needle to extrude the microcrystal-containing viscous media and it is compatible with commercially available syringes. The combination of sample delivery via protein crystals suspended in a viscous mixture and a millisecond frame rate detector enables high-throughput serial crystallography at the Australian Synchrotron. A hit-finding algorithm, based on the principles of "robust-statistics," is employed to rapidly process the data. Here we present the first SMX experimental results with a detector frame rate of 100 Hz (10 ms exposures) and the Lipidico injector using a mixture of lysozyme microcrystals embedded in high vacuum silicon grease. Details of the experimental setup, sample injector, and data analysis pipeline are designed and developed as part of the Australian Synchrotron SMX instrument and are reviewed here. Published under license by AIP Publishing.
44.	Bertilsson, Michael, et al. (author) Laboratory arrangement for soft x-ray zone-plate efficiency measurements 2007 In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 78:2, s. 026103- Journal article (peer-reviewed)abstract We demonstrate a laboratory-scale arrangement for rapid and accurate measurements of the absolute and local efficiency of soft x-ray micro zone plates in the water window. This in-house instrument is based on a single-line lambda=2.88 nm liquid-jet laser-plasma source. Measurements are performed by a simultaneous comparison of first diffraction-order photon flux with the flux in a calibrated reference signal. This arrangement eliminates existing source emission fluctuations. The performance of the method is demonstrated by the result from measurements of two similar to 55 mu m diameter nickel micro zone plates, showing a groove efficiency of 12.9%+/- 1.1% and 11.7%+/- 1.0%. Furthermore, we show that spatially resolved efficiency mapping is an effective tool for a detailed characterization of local zone plate properties. Thus, this laboratory-scale instrument allows rapid feedback to the fabrication process which is important for future improvements.
45.	Betz, B, et al. (author) Quantification of the sensitivity range in neutron dark-field imaging. 2015 In: Review of Scientific Instruments. - : AIP Publishing. - 1089-7623 .- 0034-6748. ; 86:12 Journal article (peer-reviewed)abstract In neutron grating interferometry, the dark-field image visualizes the scattering properties of samples in the small-angle and ultra-small-angle scattering range. These angles correspond to correlation lengths from several hundred nanometers up to several tens of micrometers. In this article, we present an experimental study that demonstrates the potential of quantitative neutron dark-field imaging. The dark-field signal for scattering from different particle sizes and concentrations of mono-dispersive polystyrene particles in aqueous solution is compared to theoretical predictions and the good agreement between measurements and calculations underlines the quantitative nature of the measured values and reliability of the technique with neutrons.
46.	Bielecki, J., et al. (author) Phillips-Tikhonov regularization with a priori information for neutron emission tomographic reconstruction on Joint European Torus 2015 In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 86:9 Journal article (peer-reviewed)abstract A method of tomographic reconstruction of the neutron emissivity in the poloidal cross section of the Joint European Torus (JET, Culham, UK) tokamak was developed. Due to very limited data set (two projection angles, 19 lines of sight only) provided by the neutron emission profile monitor (KN3 neutron camera), the reconstruction is an ill-posed inverse problem. The aim of this work consists in making a contribution to the development of reliable plasma tomography reconstruction methods that could be routinely used at JET tokamak. The proposed method is based on Phillips-Tikhonov regularization and incorporates a priori knowledge of the shape of normalized neutron emissivity profile. For the purpose of the optimal selection of the regularization parameters, the shape of normalized neutron emissivity profile is approximated by the shape of normalized electron density profile measured by LIDAR or high resolution Thomson scattering JET diagnostics. In contrast with some previously developed methods of ill-posed plasma tomography reconstruction problem, the developed algorithms do not include any post-processing of the obtained solution and the physical constrains on the solution are imposed during the regularization process. The accuracy of the method is at first evaluated by several tests with synthetic data based on various plasma neutron emissivity models (phantoms). Then, the method is applied to the neutron emissivity reconstruction for JET D plasma discharge #85100. It is demonstrated that this method shows good performance and reliability and it can be routinely used for plasma neutron emissivity reconstruction on JET.
47.	Binda, Federico, 1987- (author) Absolute calibration of the JET neutron profile monitor In: Review of Scientific Instruments. - 0034-6748 .- 1089-7623. Journal article (peer-reviewed)
48.	Binda, Federico, et al. (author) Forward fitting of experimental data from a NE213 neutron detector installed with the magnetic proton recoil upgraded spectrometer at JET 2014 In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 85:11, s. 11E123- Journal article (peer-reviewed)abstract In this paper, we present the results obtained from the data analysis of neutron spectra measured with a NE213 liquid scintillator at JET. We calculated the neutron response matrix of the instrument combining MCNPX simulations, a generic proton light output function measured with another detector and the fit of data from ohmic pulses. For the analysis, we selected a set of pulses with neutral beam injection heating (NBI) only and we applied a forward fitting procedure of modeled spectral components to extract the fraction of thermal neutron emission. The results showed the same trend of the ones obtained with the dedicated spectrometer TOFOR, even though the values from the NE213 analysis were systematically higher. This discrepancy is probably due to the different lines of sight of the two spectrometers (tangential for the NE213, vertical for TOFOR). The uncertainties on the thermal fraction estimates were from 4 to 7 times higher than the ones from the TOFOR analysis.
49.	Björklund, Sebastian, et al. (author) A calorimetric method to determine water activity 2011 In: Review of Scientific Instruments. - : AIP Publishing. - 1089-7623 .- 0034-6748. ; 82:11 Journal article (peer-reviewed)abstract A calorimetric method to determine water activity covering the full range of the water activity scale is presented. A dry stream of nitrogen gas is passed either over the solution whose activity should be determined or left dry before it is saturated by bubbling through water in an isothermal calorimeter. The unknown activity is in principle determined by comparing the thermal power of vaporization related to the gas stream with unknown activity to that with zero activity. Except for three minor corrections (for pressure drop, non-perfect humidification, and evaporative cooling) the unknown water activity is calculated solely based on the water activity end-points zero and unity. Thus, there is no need for calibration with references with known water activities. The method has been evaluated at 30 °C by measuring the water activity of seven aqueous sodium chloride solutions ranging from 0.1 mol kg−1 to 3 mol kg−1 and seven saturated aqueous salt solutions (LiCl, MgCl2, NaBr, NaCl, KCl, KNO3, and K2SO4) with known water activities. The performance of the method was adequate over the complete water activity scale. At high water activities the performance was excellent, which is encouraging as many other methods used for water activity determination have limited performance at high water activities.
50.	Björklund, Sebastian, et al. (author) Humidity scanning quartz crystal microbalance with dissipation monitoring setup for determination of sorption-desorption isotherms and rheological changes 2015 In: Review of Scientific Instruments. - : American Institute of Physics (AIP). - 0034-6748 .- 1089-7623. ; 86:5 Journal article (peer-reviewed)abstract A new method to determine water sorption-desorption isotherms with high resolution in the complete range of water activities (relative humidities) is presented. The method is based on quartz crystal microbalance with dissipation monitoring (QCM-D). The QCM-D is equipped with a humidity module in which the sample film is kept in air with controlled humidity. The experimental setup allows for continuous scanning of the relative humidity from either dry to humid conditions or vice versa. The amount of water sorbed or desorbed from the sample is determined from the resonance frequencies of the coated quartz sensor, via analysis of the overtone dependence. In addition, the method allows for characterization of hydration induced changes of the rheological properties from the dissipation data, which is closely connected to the viscoelasticity of the film. The accuracy of the humidity scanning setup is confirmed in control experiments. Sorption-desorption isotherms of pig gastric mucin and lysozyme, obtained by the new method, show good agreement with previous results. Finally, we show that the deposition technique used to coat the quartz sensor influences the QCM-D data and how this issue can be used to obtain further information on the effect of hydration. In particular, we demonstrate that spin-coating represents an attractive alternative to obtain sorption-desorption isotherms, while drop-coating provides additional information on changes of the rheological properties during hydration.

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