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C.a.n. Conde - One of the best experts on this subject based on the ideXlab platform.
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PERFORMANCE OF A ROOM TEMPERATURE GAS PROPORTIONAL Scintillation Counter IN X-RAY ANALYSIS OF METALLIC ALLOYS EXCITED WITH ALPHA PARTICLES
2020Co-Authors: F I G M Borges, A M F Trindade, F P Santos, T H V T Dias, S. Do J. C. Carmo, F P S C Gil, R Curado M Da Silva, C.a.n. CondeAbstract:ABSTRACT A gas proportional Scintillation Counter with a large detection area (≈ 1000 mm 2 ) is described. The curved grid technique was used for solid angle compensation and the photosensor is a photomultiplier tube with a 50 mm diameter quartz window. For an energy range between 2.5 and 25 keV it can work at counting rates up to 20,000 events/s, presenting for 5.9 keV X-rays an energy resolution of 7.8% for a 1 mm collimated beam that degrades to 9% when the full detector window is used. Results for its performance in the analysis of some common metallic alloys excited with alpha particles are presented
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a new technique for gaseous radiation detectors the multigrid high pressure xenon gas proportional Scintillation Counter
IEEE Transactions on Nuclear Science, 2010Co-Authors: F I G M Borges, Sergio Do J C Carmo, Joao C R Mariquito, A M F Trindade, C.a.n. CondeAbstract:A new technique is presented for high-pressure gaseous radiation detectors leading to pulse amplitudes at least one order of magnitude larger than in ionization-chamber-based gamma-ray detectors. The technique uses room-temperature pure Xe or Xe-based gaseous mixtures at pressures of about 5-20 bar (or higher) to detect ionizing radiation in a multigrid high-pressure gas proportional Scintillation Counter (MGHP-GPSC) with a CsI deposit as the photocathode in direct contact with the gas, with no optical windows. The detector relies on secondary Scintillation as the amplification stage followed by photoelectron production in a CsI photocathode layer. Experimental results are presented for a small prototype filled with pure Xe up to 5 bar, showing that the principle of operation of the detector works. The maximum detector gain obtained so far is about 10.
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a new technique for gaseous gamma ray detectors the multigrid high pressure xenon gas proportional Scintillation Counter
IEEE Nuclear Science Symposium, 2009Co-Authors: F I G M Borges, Sergio Do J C Carmo, Joao C R Mariquito, A M F Trindade, C.a.n. CondeAbstract:A new technique is presented for high pressure gaseous radiation detectors leading to pulse amplitudes about one order of magnitude larger than ionization chamber based gamma ray detectors. The technique uses room temperature Xe based gaseous mixtures at pressures of about 5 to 20 atm (or higher) to detect ionizing radiation in a multigrid high pressure gas proportional Scintillation Counter (MGHP-GPSC) with a CsI deposit as the photocathode and no optical windows. The detector relies on secondary Scintillation for the charge amplification stage rather than on charge avalanche multiplication as in proportional Counters. Experimental results are presented for a small prototype filled with pure Xe up to 5 atm showing that the principle of operation of the detector works. The detector maximum gain obtained in the first results is about 10.
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Performance of Argon-Xenon mixtures in a gas proportional Scintillation Counter for the 0.1-10 keV X-ray region
2008 IEEE Nuclear Science Symposium Conference Record, 2008Co-Authors: S. Do J. C. Carmo, F I G M Borges, C.a.n. CondeAbstract:The performance of a gas proportional Scintillation Counter filled with either pure Xe or Ar-Xe mixtures is described for the 0.1-10 keV X-ray energy range. It is shown that the spectra tail distortion exhibited by Xe filled gaseous detectors for soft X-rays below 2 keV is reduced if Ar-Xe mixtures are used. The peak-to-valley ratio increases by a factor of about 2 or 3 as the Xe concentration is reduced from 100% to 5%. Moreover, the energy resolutions for such mixtures are similar to the ones for pure Xe.
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a gas proportional Scintillation Counter for x ray spectrometry in the 0 1 3 kev range
X-Ray Spectrometry, 2004Co-Authors: F I G M Borges, J Dos M F Santos, F P Santos, T H V T Dias, C.a.n. CondeAbstract:Results for the energy resolution of a uniform-field gas proportional-Scintillation Counter are presented for the range 0.1–3 keV. A comparison with results from the literature shows that the detector is most suitable for this energy range. Examples of x-ray fluorescence pulse-height distributions from geological and industrial samples are presented. Copyright © 2004 John Wiley & Sons, Ltd.
J Dos M F Santos - One of the best experts on this subject based on the ideXlab platform.
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a gas proportional Scintillation Counter for x ray spectrometry in the 0 1 3 kev range
X-Ray Spectrometry, 2004Co-Authors: F I G M Borges, J Dos M F Santos, F P Santos, T H V T Dias, C.a.n. CondeAbstract:Results for the energy resolution of a uniform-field gas proportional-Scintillation Counter are presented for the range 0.1–3 keV. A comparison with results from the literature shows that the detector is most suitable for this energy range. Examples of x-ray fluorescence pulse-height distributions from geological and industrial samples are presented. Copyright © 2004 John Wiley & Sons, Ltd.
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a large area gas proportional Scintillation Counter for balloon borne solar x ray spectrometry
IEEE Transactions on Nuclear Science, 2002Co-Authors: Natal H Da Luz, J.f.c.a. Veloso, C.a.n. Conde, J Dos M F Santos, Rui Curado M Da Silva, H R Pan, H A LinAbstract:A compact xenon filled gas proportional Scintillation Counter (GPSC) having a window area of 12.5 cm/sup 2/ coupled to low weight, low volume and low power associated electronics is described to be used in a balloon gondola to fly at high altitudes (30 to 40 km) and measure X-ray spectra in the 20 to 80 keV energy range, arising from solar flares. The detector has an energy resolution of 4.3% at 59.6 keV for the full window opening, and 2.7% for a 2-mm-diameter collimated X-ray beam.
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a driftless gas proportional Scintillation Counter for muonic hydrogen x ray spectroscopy under strong magnetic fields
Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2001Co-Authors: J.f.c.a. Veloso, C.a.n. Conde, J Dos M F Santos, F Mulhauser, P Knowles, C Donchegay, O Huot, D Taqqu, F KottmannAbstract:Abstract An experiment involving muonic hydrogen requires an X-ray detector having large area and working under strong magnetic fields (5 T) with good energy and timing resolution. A compact, driftless gas proportional Scintillation Counter (GPSC) capable of operating under such magnetic fields is investigated. This GPSC uses a CsI photocathode deposited onto a microstrip plate as the UV Scintillation readout photosensor. This photocathode has the advantage of operating in direct contact with the Scintillation gas. The detector is filled with pure xenon and is designed to have a high detection efficiency for 2 keV X-rays. Energy resolutions of 23% and 22% were obtained for 1.74 and 2.3 keV X-rays, respectively. The low-energy detector limit due to the electronic noise is 300 eV. Its performance in the presence of strong magnetic fields was tested. At magnetic field of 5 T the detector pulse amplitudes are reduced by less than 25%, while the detector energy resolution and pulse rise time present a relative increase of less than 10%.
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gas proportional Scintillation Counters with a csi covered microstrip plate uv photosensor for high resolution x ray spectrometry
Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2001Co-Authors: J.f.c.a. Veloso, J Dos M F Santos, C.a.n. CondeAbstract:Abstract A xenon-filled gas proportional Scintillation Counter for X-ray spectrometry is described. The detector uses a microstrip plate covered with a thin CsI film as a photosensor rather than the usual photomultiplier tube. The achieved energy resolution for 5.9 keV X-rays is 12% when the microstrip is operated within the xenon volume and 10.5% when the microstrip is operated in a P-10 environment, separated from the xenon volume by a quartz window.
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a xenon gas proportional Scintillation Counter with a uv sensitive large area avalanche photodiode
IEEE Nuclear Science Symposium, 2000Co-Authors: J A M Lopes, R.e. Morgado, J Dos M F Santos, C.a.n. CondeAbstract:The performance characteristics of a xenon gas proportional Scintillation Counter instrumented with an large-area avalanche photodiode with enhanced UV-sensitivity were evaluated. By integrating the photodiode within the xenon gas envelope of the scintillator, the intervening quartz window was eliminated. Energy resolutions of 7.8% and 4.4% were measured for 5.9-keV and 22.1-keV X-rays, respectively. The results demonstrate that large-area avalanche photodiodes may replace photomultiplier tubes without compromising the performance of the gas proportional Scintillation Counter.
F I G M Borges - One of the best experts on this subject based on the ideXlab platform.
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PERFORMANCE OF A ROOM TEMPERATURE GAS PROPORTIONAL Scintillation Counter IN X-RAY ANALYSIS OF METALLIC ALLOYS EXCITED WITH ALPHA PARTICLES
2020Co-Authors: F I G M Borges, A M F Trindade, F P Santos, T H V T Dias, S. Do J. C. Carmo, F P S C Gil, R Curado M Da Silva, C.a.n. CondeAbstract:ABSTRACT A gas proportional Scintillation Counter with a large detection area (≈ 1000 mm 2 ) is described. The curved grid technique was used for solid angle compensation and the photosensor is a photomultiplier tube with a 50 mm diameter quartz window. For an energy range between 2.5 and 25 keV it can work at counting rates up to 20,000 events/s, presenting for 5.9 keV X-rays an energy resolution of 7.8% for a 1 mm collimated beam that degrades to 9% when the full detector window is used. Results for its performance in the analysis of some common metallic alloys excited with alpha particles are presented
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a new technique for gaseous radiation detectors the multigrid high pressure xenon gas proportional Scintillation Counter
IEEE Transactions on Nuclear Science, 2010Co-Authors: F I G M Borges, Sergio Do J C Carmo, Joao C R Mariquito, A M F Trindade, C.a.n. CondeAbstract:A new technique is presented for high-pressure gaseous radiation detectors leading to pulse amplitudes at least one order of magnitude larger than in ionization-chamber-based gamma-ray detectors. The technique uses room-temperature pure Xe or Xe-based gaseous mixtures at pressures of about 5-20 bar (or higher) to detect ionizing radiation in a multigrid high-pressure gas proportional Scintillation Counter (MGHP-GPSC) with a CsI deposit as the photocathode in direct contact with the gas, with no optical windows. The detector relies on secondary Scintillation as the amplification stage followed by photoelectron production in a CsI photocathode layer. Experimental results are presented for a small prototype filled with pure Xe up to 5 bar, showing that the principle of operation of the detector works. The maximum detector gain obtained so far is about 10.
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a new technique for gaseous gamma ray detectors the multigrid high pressure xenon gas proportional Scintillation Counter
IEEE Nuclear Science Symposium, 2009Co-Authors: F I G M Borges, Sergio Do J C Carmo, Joao C R Mariquito, A M F Trindade, C.a.n. CondeAbstract:A new technique is presented for high pressure gaseous radiation detectors leading to pulse amplitudes about one order of magnitude larger than ionization chamber based gamma ray detectors. The technique uses room temperature Xe based gaseous mixtures at pressures of about 5 to 20 atm (or higher) to detect ionizing radiation in a multigrid high pressure gas proportional Scintillation Counter (MGHP-GPSC) with a CsI deposit as the photocathode and no optical windows. The detector relies on secondary Scintillation for the charge amplification stage rather than on charge avalanche multiplication as in proportional Counters. Experimental results are presented for a small prototype filled with pure Xe up to 5 atm showing that the principle of operation of the detector works. The detector maximum gain obtained in the first results is about 10.
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Performance of Argon-Xenon mixtures in a gas proportional Scintillation Counter for the 0.1-10 keV X-ray region
2008 IEEE Nuclear Science Symposium Conference Record, 2008Co-Authors: S. Do J. C. Carmo, F I G M Borges, C.a.n. CondeAbstract:The performance of a gas proportional Scintillation Counter filled with either pure Xe or Ar-Xe mixtures is described for the 0.1-10 keV X-ray energy range. It is shown that the spectra tail distortion exhibited by Xe filled gaseous detectors for soft X-rays below 2 keV is reduced if Ar-Xe mixtures are used. The peak-to-valley ratio increases by a factor of about 2 or 3 as the Xe concentration is reduced from 100% to 5%. Moreover, the energy resolutions for such mixtures are similar to the ones for pure Xe.
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a gas proportional Scintillation Counter for x ray spectrometry in the 0 1 3 kev range
X-Ray Spectrometry, 2004Co-Authors: F I G M Borges, J Dos M F Santos, F P Santos, T H V T Dias, C.a.n. CondeAbstract:Results for the energy resolution of a uniform-field gas proportional-Scintillation Counter are presented for the range 0.1–3 keV. A comparison with results from the literature shows that the detector is most suitable for this energy range. Examples of x-ray fluorescence pulse-height distributions from geological and industrial samples are presented. Copyright © 2004 John Wiley & Sons, Ltd.
John B. Hursh - One of the best experts on this subject based on the ideXlab platform.
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Estimation of Total Body Fat from Potassium-40 Content
Nutrition reviews, 2009Co-Authors: Gilbert B. Forbes, James Gallup, John B. HurshAbstract:On the assumption that the potassium content of the lean body mass is constant, it should be possible to estimate fat content in living man from a measurement of potassium-40 activity in the whole-body Scintillation Counter. A series of such measurements on children and young adults shows good correlations with skin-fold thickness and weight/height ratio as indices of fatness.
G Shaw - One of the best experts on this subject based on the ideXlab platform.
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measuring radon 222 in soil gas with high spatial and temporal resolution
Journal of Environmental Radioactivity, 2017Co-Authors: Darren Huxtable, David Read, G ShawAbstract:In order to exploit 222Rn as a naturally-occurring tracer in soils we need to sample and measure radon isotopes in soil gas with high spatial and temporal resolution, without disturbing in situ activity concentrations and fluxes. Minimization of sample volume is key to improving the resolution with which soil gas can be sampled; an analytical method is then needed which can measure radon with appropriate detection limits and precision for soil gas tracer studies. We have designed a soil gas probe with minimal internal dead volume to allow us to sample soil gas volumes of 45 cm3. Radon-222 is extracted from these samples into a mineral oil-based Scintillation cocktail before counting on a conventional liquid Scintillation Counter. A detection limit of 320 Bq m-3 (in soil gas) is achievable with a one hour count. This could be further reduced but, in practice, is sufficient for our purpose since 222Rn in soil gas typically ranges from 2,000 - 50,000 Bq m-3. The method is simple and provides several advantages over commonly used field-portable instruments, including smaller sample volumes, speed of deployment and reliability under field conditions. The major limitation is the need to count samples in a liquid Scintillation Counter within 2 – 3 days of collection, due to the short (3.824 day) radioactive half-life of 222Rn. The method is not applicable to the very short-lived (55 second half-life) 220Rn.