| 1. |
- Akselsson, Roland
(författare)
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Aerosol Sampling and Samplers Matched to PIXE Analysis
- 1984
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Ingår i: Nuclear Instruments and Methods in Physics Research B. ; 3:1-3, s. 425-430
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Tidskriftsartikel (refereegranskat)abstract
- The PIXE method constitutes a tool for fast, reliable multi-elemental analysis of small samples. These properties are very attractive in aerosol sciences and in aerosol monitoring programmes. Thus PIXE allows the use of small samplers which are easy to deploy and could be operated for long periods even at more or less remote sites. For working environment aerosols, samplers with time resolution can be, and in a few cases are, designed for personal continuous sampling in the breathing zone. For both practical and economical reasons, PIXE, in many applications, facilitates the gathering of multi-elemental information about aerosols with more detailed size, site and time resolution when compared with conventional techniques. Conditions for maximum exploitation of the PIXE technique in aerosol research are development of suitable samplers, optimal sampling strategies and adequate analytical procedures taking the unique properties of PIXE into consideration. These developmental tasks require intense interactions between several research and development disciplines. In this paper, the state of the art of samplers matched to the PIXE method is reviewed.
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| 2. |
- Akselsson, Roland
(författare)
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PIXE in 1980: Summary of the Second International Conference on Particle Induced X-Ray Emission and its Analytical Applications
- 1981
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Ingår i: IEEE Transactions on Nuclear Science. - 0018-9499. ; NS-28:2, s. 1369-1373
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Tidskriftsartikel (refereegranskat)abstract
- The Second International Conference on Particle Induced X-ray Emission (PIXE) and its analytical applications was held in Lund, Sweden, June 9-12, 1980. About a hundred papers were presented, including seven invited talks (PIXE and particle scattering, microbeam analysis (2), applications to aerosols (2) and biological samples (2)). The main impression left by the conference was that both the PIXE method and its applications are in a phase of fast development. Considerable effort has successfully been devoted to optimizing the basic PIXE technique. Also the great advantage of simultaneously getting information about lighter elements and sample mass was reported to have been successfully employed in routine analyses. PIXE, which was initially considered to be a method mainly for thin samples, has also been shown to be competitive for a variety of thick samples. Consequently there were several papers dealing with problems characteristic of thick sample analysis. In this context, external beam analysis was also thoroughly discussed. Charged particle microprobes seem to be very attractive and several investigators reported progress on microprobe development and very interesting results of applied work. It is gratifying to note the increasing interest shown by non-physicists in using PIXE. These activities have greatly contributed to the fact that PIXE has now in a few areas left the phase of feasibility tests. E.g. an imposing amount of data from aerosol studies was presented. With the PIXE method, it is feasible to perform series of measurements over a long period of time, many samples in parallel and/or samples from sites of poor accessibility. However, the advantages of PIXE may be further exploited in aerosol investigations and some promising lines of sampler development were reported. Sample preparation techniques are crucial for applications to biological samples and several laboratories are engaged in such developmental work,. However, it was also evident that PIXE us already giving significant contributions to research in biology and medicine.
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| 3. |
- Bohgard, Mats, et al.
(författare)
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MeV Protons for the Characterization of Aerosols in Work Environments
- 1981
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 181:1-3, s. 459-463
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Tidskriftsartikel (refereegranskat)abstract
- In this paper the advantages of accelerator-based chemical analysis of work environment aerosols are discussed. Use of the PIXE method is central, but in order to take full advantage of the possibilities of an accelerator laboratory, it should be combined with nuclear methods such as particle-induced nuclear reactions and/or particle scattering for simultaneous measurements of light elements. It is also important to develop optimum sampling techniques for the analytical methods required. Some information about the current set-up in Lund is given. In a companion paper, the potential of PIXE for work environment tasks is illustrated by a summary of the design of two major studies. Some results are also included.
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| 4. |
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| 5. |
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| 6. |
- Carlsson, Lars-Eric, et al.
(författare)
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Applicability of PIXE and XRF to Fast Drill Core Analysis in Air
- 1981
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Ingår i: Advances in X-Ray Analysis. ; 24, s. 313-321
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Tidskriftsartikel (refereegranskat)abstract
- The properties of particle-induced X-ray emission, PIXE, and secondary target mode X-ray fluorescence, XRF, applied to the analysis of unprepared drill cores in open air have been evaluated. Typical detection limits for elements heavier than Mg have been determined for a PIXE-system with an external 2.55 MeV proton beam and for an XRF-system with Ti, Mo and Tb secondary targets. These two systems were found to have similar detection limits for most elements in a typical geological sample. The heterogeneous composition of drill cores prevents the performance of accurate matrix corrections, though calculations using fundamental parameters show that in the PIXE analysis of elements heavier than Ca, these corrections are much less sensitive to variations in the matrix composition than in the XRF analysis.
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| 7. |
- Carlsson, Lars-Eric, et al.
(författare)
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Miljöanalys med hjälp av kärnfysikalisk teknik - PIXE
- 1981
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Ingår i: Ordo. - 0345-8970. ; 15:3, s. 3-8
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Tidskriftsartikel (refereegranskat)abstract
- Under de senaste tio åren har en känslig analysmetod för grundämnen utvecklats vid institutionen för kärnfysik vid LTH. Metoden kallas PIXE (Particle Induced X-ray Emisson) och medger att mycket små förekomster (109 – 1012 g) av grundämnen kanbestämmas i små prov. Metoden är snabb. Ett par minuters analys ger en samtidig bestämning av ett stort antal grundämnen. Analysmetoden används nu i ett stort antal laboratorier runt om i världen och har funnit tillämpning inom en rad olika områden såsom medicin, biologi, yrkes- och omgivningshygien, meteorologi, geologi samt arkeologi. I Lund har metoden huvudsakligen använts för omfattande studier av föroreningar i arbetsmiljö och yttre miljö, varför vi först redogör för vårt arbete inom dessa tillämpningsområden, varefter vi beskriver de fysikaliska principerna för analysmetoden och utvecklingsarbetet med den.
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| 8. |
- Carlsson, Lars-Eric, et al.
(författare)
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PIXE Analysis of Samples of Intermediate Thickness
- 1981
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 181:1-3, s. 179-183
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Tidskriftsartikel (refereegranskat)abstract
- A procedure for making accurate matrix corrections in PIXE analyses of samples of intermediate thickness has been developed. The transmission of a collimated X-ray beam through different parts of the sample is measured with a Si(Li) detector to determine the thickness and shape of the sample. Experiments have been performed using uniform polymer foils doped with known concentrations of different elements and with thicknesses ranging from 1.5 to 11 mg/cm2. The results from these samples indicate that the accuracy of the correction procedure is better than 5%. The correction procedure has been applied to, e.g., samples obtained in single orifice cascade impactors.
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| 9. |
- Carlsson, Lars-Eric, et al.
(författare)
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Rapid Determination of Major and Trace Elements in Geological Material with Proton-Induced X-Ray and Gamma-Ray Emission
- 1981
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 181:1-3, s. 531-537
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Tidskriftsartikel (refereegranskat)abstract
- The simultaneous detection of proton-induced X-rays and gamma-rays enables rapid determination of both major and trace elements in thick homogeneous samples. Using protons of energy 2.55 MeV, the atomic numbers of the elements detectable with this technique were Z=3, 5, 9, 11–13 from gamma-ray analysis and Z=13–92 from X-ray analysis. Thick target concentrations were determined from a thoroughly made thin target calibration and from matrix-dependent conversion factors calculated from fundamental parameters. The major compositions of samples needed in these calculations are derived in an iterative procedure using the spectra recorded. The method proposed has been tested on six USGS rock standards. Detection limits for one of the standards are presented. Approximately 20 elements were detected in each sample 5 min irradiations. For elements well above their detection limits, the results are typically accurate to within 5%. The precision of repeated day-to-day analysis is about 2% (one standard deviation).
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| 10. |
- Forslind, Bo, et al.
(författare)
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Elemental Analysis on Freeze-Dried Sections of Human Skin: Studies by Electron Microprobe and Particle Induced X-Ray Emission Analysis
- 1984
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Ingår i: Scanning Electron Microscopy. - 0586-5581. ; , s. 755-759
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Tidskriftsartikel (refereegranskat)abstract
- The possibility of using the proton microprobe (PMP) in the elemental analysis of dermatological material, under conditions where the spatial resolution can be restricted to a few micrometers, was demonstrated. Comparison with the electron microprobe (EMP) technique using duplicate sections from the same human skin biopsies revealed that the PMP and EMP techniques are complementary and yield closely corresponding elemental distributions for elements of dermatological interest. The concentrations of phosphorus and potassium were low in the dermis, high in the stratum basale and stratum spinosum, and decreased markedly in the stratum granulosum to a low level in the stratum corneum. The sulfur concentration was highest in the stratum corneum.
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