| 1. |
- Auzelyte, Vaida, et al.
(författare)
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The beam blanking system for microlithography at Lund Nuclear microprobe
- 2004
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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
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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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| 2. |
- Bulow, K, et al.
(författare)
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The penetration depth and lateral distribution of pigment related to the pigment grain size and the calendering of paper
- 2002
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - 0168-583X. ; 189, s. 308-314
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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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| 3. |
- Elfman, Mikael, et al.
(författare)
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The Lund Nuclear Microprobe sub-micron set-up. Part III: Sample stage, optical imaging and detector configuration in the experimental chamber
- 2005
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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
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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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| 4. |
- Imran, Tajammal, et al.
(författare)
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Quantifying diffused hydrogen in AISI-52100 bearing steel and in silver steel under tribo-mechanical action: Pure rotating bending, sliding-rotating bending, rolling-rotating bending and uni-axial tensile loading
- 2006
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Ingår i: Papers presented at the 11th Nordic Symposium on Tribology, NORDTRIB 2004 (Wear). - : Elsevier BV. - 0043-1648 .- 1873-2577. ; 261:1, s. 86-95
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Konferensbidrag (refereegranskat)abstract
- Hydrogen embrittlement is often a catastrophic phenomenon of machine elements failure under cyclic stresses. This hydrogen is generated as a result of tribo-chemical and mechanical actions on the working surfaces. This hydrogen can have three different zones or stages of behaviour under tribo-mechanical actions. Firstly, it can strongly adsorb on the mating surfaces at a shallow subsurface zone and take up the load in the boundary-lubricating regime and reduce the coefficient of friction. At a second stage, it can diffuse to the deep subsurface zone where it might work together with Hertzian stresses and embrittle the subsurface zone. The last zone of hydrogen activity is the bulk of the bearing steel where it is known to collect under the action of tensile stresses and degrade the bearing steel and hence resulting in catastrophic failure. It is important and interesting to follow up the presence of hydrogen in these zones in order to predict the safe functioning of the machine elements. In addition to this a clear distinction must be made between the internal hydrogen embrittlement and environmental hydrogen embrittlement. Two important behaviours of hydrogen are studied and quantification was made by a melting sample technique. Dependence of hydrogen diffusion on the variation of tribo-mechanical action is shown in this work. This was done by studying the pure rotating bending, rotating bending with combination of sliding and rolling motion of the mating surfaces and uni-axial tensile experiments in pure water environment to see the diffusion of hydrogen into or out of the AISI-52100 bearing steel and in silver steel. Two different approaches were adopted in order to investigate the presence of hydrogen in three zones under the action of different stress states. The two techniques are melting sample technique by using hydrogen analyser and elastic recoil detection analysis, an ion beam technique. It is believed until now that hydrogen spread is homogeneous in the bearing steel. The results obtained showed that the inherent amount of hydrogen in steel samples is non-homogeneous and it was learnt that inherent amount of hydrogen in the steel samples is very important in order to support the boundary lubrication by hydrogen. Content of hydrogen in the steel samples showed a relation to the increasing number of cyclic stresses. The sliding-rotating bending stress state showed a considerable wear of the surfaces but the content of hydrogen was not very high in that sample when compared to the samples that were run under pure rotating bending stress state. (c) 2005 Elsevier B.V. All rights reserved.
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| 5. |
- Kristiansson, Per, et al.
(författare)
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Development of a system for determination of the C-13/C-12 isotopic ratio with high spatial resolution
- 2004
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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
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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.
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| 6. |
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| 7. |
- Pallon, Jan, et al.
(författare)
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An off-axis STIM procedure for precise mass determination and imaging
- 2004
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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
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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.
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| 8. |
- Pallon, Jan, et al.
(författare)
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Optimization of PIXE-sensitivity for detection of Ti in thin human skin sections
- 2005
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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
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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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| 9. |
- Shariff, Asad, et al.
(författare)
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Calibration of a new chamber using GUPIX software package for PIXE analysis
- 2002
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - 0168-583X. ; 189:1-4, s. 131-137
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Tidskriftsartikel (refereegranskat)abstract
- A new chamber has been designed and constructed for the second beam line at the Lund Nuclear Microprobe facility, Sweden. The aim with the chamber is to perform standardized analyses with most of the nuclear analytical techniques (proton induced X-ray emission, particle elastic scattering analysis, proton induced gamma emission, nuclear reaction analysis, etc.) with a millimetre size beam. The beam line and chamber constructions are described in this paper. The possibility to run samples in batch. and the special arrangement developed for this is described. A mass calibration of the PIXE set-up has been done with MicroMatter thin film standards and other thick standards. The spectra were acquired with CAMAC based data acquisition system with Kmax interfacing software. The GUPIX software package recently installed in our laboratory has been used to process the PIXE spectra and the results are compared with the certified values. For standardization the instrumental constant H (solid angle and correction factor) is determined relying completely on the GUPIX data base (cross-sections, fluorescence and Coster-Kronig probabilities, stopping powers and attenuation coefficients) for a large set of elements. These H values are saved inside the GUPIX library, to be used in future analysis.
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| 10. |
- Shariff, Asad, et al.
(författare)
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Characterization of a new large area HPGe X-ray detector for low beam current application
- 2004
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 219-20, s. 494-498
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Tidskriftsartikel (refereegranskat)abstract
- In the new sub-micron beamline at the Lund Nuclear Microprobe facility a special large area HPGe X-ray detector has been installed. It consists of eight 100-mm(2)-size detector elements arranged in an annular formation around the beam entrance hole. Different parameters like FWHM, FWTM, peak-to-background ratio and peak-to-valley ratio for each individual detector element as well as their sum spectra have been investigated. The data handling, i.e. how eight parallel signals are individually stored and summed together, has been discussed. The possibility to use the detector for simultaneous measurement of high and low energy photons, i.e. PINE combined with PIGE has been demonstrated. (C) 2004 Elsevier B.V. All rights reserved.
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