The Experts below are selected from a list of 27345 Experts worldwide ranked by ideXlab platform
C A N Conde - One of the best experts on this subject based on the ideXlab platform.
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xenon neon gas proportional Scintillation Counters for x rays below 2 kev a monte carlo simulation study
IEEE Transactions on Nuclear Science, 2002Co-Authors: F I G M Borges, F P Santos, T H V T Dias, P J B M Rachinhas, C A N Conde, A D StaufferAbstract:The energy spectra of X-rays with energies below 2 keV measured at atmospheric pressure with standard Xe gas detectors, such as gas proportional-Scintillation Counters, exhibit distortions that are related to losses of electrons and fluorescence photons to the radiation window. In this paper, a Monte Carlo simulation method that takes into account these losses investigates the use of Xe-Ne mixtures as detection media in this energy range. For a total pressure of 1 atm, energy spectra were calculated for nine mixtures with Xe concentrations varying from 10% to 100%. The results have shown that the addition of Ne to Xe significantly reduces distortion and improves the energy resolution of the full energy peaks.
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xenon neon gas proportional Scintillation Counters for x rays below 2 kev experimental results
IEEE Nuclear Science Symposium, 2002Co-Authors: F I G M Borges, F P Santos, J Dos M F Santos, T H V T Dias, P J B M Rachinhas, C A N CondeAbstract:The energy spectra of X-rays with energies below 2 keV measured with standard Xe filled gas proportional-Scintillation Counters at atmospheric pressure exhibit a distorted tail toward the low energy region, due to the loss of electrons to the detector entrance window. In this framework, a Monte Carlo simulation study taking into account these losses has previously investigated the use of Xe-Ne mixtures as gas proportional Scintillation Counters (GPSC) fillings. It was shown that the addition of Ne to Xe reduces spectra distortion and improves the overall detector performance. In the present work, we present an experimental study of the performance of a GPSC for different Xe-Ne mixtures and X-ray energies in the 200 to 2000 eV energy range and compare the results with the previously obtained Monte Carlo data.
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gas proportional Scintillation Counters for the spl mu p lamb shift experiment
IEEE Nuclear Science Symposium, 2001Co-Authors: J F C A Veloso, C A N Conde, J A M Lopes, Luis Fernandes, E D C Freitas, O Huot, R Knowles, F Kottmann, F Mulhauser, J Dos M F SantosAbstract:Large-area 1.9-keV X-ray detectors operating in magnetic fields up to 5 T are required for the /spl mu/p-Lamb shift experiment. Xenon gas proportional Scintillation Counters provide high detection efficiency together with good energy and timing resolutions. Three prototypes with alternative vacuum ultraviolet photosensors of the xenon Scintillation light are explored and discussed: a CsI-coated microstrip plate either integrated within the xenon envelope or in a separate chamber in a P-10 atmosphere and an avalanche photodiode integrated within the xenon envelope.
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development of portable gas proportional Scintillation Counters for x ray spectrometry
X-Ray Spectrometry, 2001Co-Authors: J Dos M F Santos, F P Santos, T H V T Dias, P J B M Rachinhas, J F C A Veloso, J A M Lopes, P C P S Simoes, L Requicha F Ferreira, C A N CondeAbstract:A review on gas proportional Scintillation Counters (GPSCs) is presented. Recent achievements towards the portability of simple, inexpensive and compact GPSCs are discussed. Compensation of solid angle effects with the curved grid technique can be used to produce non-focused GPSCs with medium-sized radiation windows, at least up to 80% of the photosensor active diameter, without degradation of detector performance. Low power-consuming and compact vacuum UV photosensors that can operate in direct contact with the Scintillation gas, as an alternative to photomultiplier tubes, are now available. Small gettering devices with a low-power built-in heating elements have been shown to be sufficient for the required gas purification in GPSCs assembled with simple and inexpensive techniques, such as the use of epoxies for ceramic-to-metal joints.
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compact high voltage and optocoupled electronics for gas proportional Scintillation Counters
IEEE Transactions on Nuclear Science, 2000Co-Authors: R M C Silva, C A N CondeAbstract:Compact (less than 2 dm/sup 3/), low weight (less than 1 kg) and low power (less than 5 W) electronic circuits for large window area (20 cm/sup 2/) Gas Proportional Scintillation Counters (GPSCs) with ellipsoidal grid have been developed for the detection of solar X-rays in balloon borne experiments. The electronics consist of amplification stages and modular power supplies. It includes a 6 kV detector supply, that for the sake of compactness and power saving has a relatively high ripple (/spl plusmn/2 V) that does not affect the performance of system, since the pulses are optically coupled to ground. Details of the circuits are given together with the control and data acquisition interface electronics. X-ray spectra demonstrating the performance of the GPSC and associated electronics are presented.
J Dos M F Santos - One of the best experts on this subject based on the ideXlab platform.
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a new method for pulse analysis of driftless gas proportional Scintillation Counters
Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2003Co-Authors: P C P S Simoes, J Dos M F Santos, J F C A Veloso, D S Covita, R E MorgadoAbstract:Abstract A new method for pulse analysis of driftless-gas proportional Scintillation Counters (GPSCs) is presented. With this method the requirement for additional analog or digital signal time-analysis and pulse-amplitude correction currently used is eliminated. In contrast to conventional- and driftless-GPSCs that have always relied on long shaping-time constants (several μs), the use of very short linear amplifier shaping-time constants (∼50 ns) enables pulse shapes to closely represent the Scintillation light-pulse time-profile. Since the number of detected photons in the photosensor increases continuously with depth due to the increase in the solid angle subtended by the photosensor, a maximum is achieved when the primary electron cloud is closest to the anode. This maximum depends only on the number of primary electrons in that cloud, regardless of where the X-ray absorption took place, and is proportional to the X-ray energy.
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xenon neon gas proportional Scintillation Counters for x rays below 2 kev experimental results
IEEE Nuclear Science Symposium, 2002Co-Authors: F I G M Borges, F P Santos, J Dos M F Santos, T H V T Dias, P J B M Rachinhas, C A N CondeAbstract:The energy spectra of X-rays with energies below 2 keV measured with standard Xe filled gas proportional-Scintillation Counters at atmospheric pressure exhibit a distorted tail toward the low energy region, due to the loss of electrons to the detector entrance window. In this framework, a Monte Carlo simulation study taking into account these losses has previously investigated the use of Xe-Ne mixtures as gas proportional Scintillation Counters (GPSC) fillings. It was shown that the addition of Ne to Xe reduces spectra distortion and improves the overall detector performance. In the present work, we present an experimental study of the performance of a GPSC for different Xe-Ne mixtures and X-ray energies in the 200 to 2000 eV energy range and compare the results with the previously obtained Monte Carlo data.
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gas proportional Scintillation Counters for the spl mu p lamb shift experiment
IEEE Nuclear Science Symposium, 2001Co-Authors: J F C A Veloso, C A N Conde, J A M Lopes, Luis Fernandes, E D C Freitas, O Huot, R Knowles, F Kottmann, F Mulhauser, J Dos M F SantosAbstract:Large-area 1.9-keV X-ray detectors operating in magnetic fields up to 5 T are required for the /spl mu/p-Lamb shift experiment. Xenon gas proportional Scintillation Counters provide high detection efficiency together with good energy and timing resolutions. Three prototypes with alternative vacuum ultraviolet photosensors of the xenon Scintillation light are explored and discussed: a CsI-coated microstrip plate either integrated within the xenon envelope or in a separate chamber in a P-10 atmosphere and an avalanche photodiode integrated within the xenon envelope.
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a simple approach to x ray spectrometry with driftless gas proportional Scintillation Counters
IEEE Nuclear Science Symposium, 2001Co-Authors: P C P S Simoes, J Dos M F Santos, D S Covita, C M B Monteiro, R E MorgadoAbstract:Driftless gas proportional Scintillation Counters are used not only for soft X-ray spectrometry but also for X-rays with energies in the 0.1- to 25-keV region. At the higher energies, however, pulse amplitudes will depend on where the absorption occurred in the detector. Pulse-shape analysis with either analog or digital pulse techniques is required to restore proportionality between the measured pulse and the energy of the X-ray. In this work we describe a simpler approach to driftless gas proportional Scintillation counter spectrometry at higher energies. The method eliminates the requirement for additional analog electronics or digital signal processing with only a modest amount of energy-dependent degradation in overall performance. The approach relies on short amplifier time constants and allows tradeoffs in the design of X-ray spectrometers whose performance requirements do not justify the complexity of a fully compensated system. We report the results of a comprehensive study of the performance characteristics of a driftless GPSC using short time constants with no additional compensation and compare its performance with that of a fully compensated digital system as a function of X-ray energy.
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development of portable gas proportional Scintillation Counters for x ray spectrometry
X-Ray Spectrometry, 2001Co-Authors: J Dos M F Santos, F P Santos, T H V T Dias, P J B M Rachinhas, J F C A Veloso, J A M Lopes, P C P S Simoes, L Requicha F Ferreira, C A N CondeAbstract:A review on gas proportional Scintillation Counters (GPSCs) is presented. Recent achievements towards the portability of simple, inexpensive and compact GPSCs are discussed. Compensation of solid angle effects with the curved grid technique can be used to produce non-focused GPSCs with medium-sized radiation windows, at least up to 80% of the photosensor active diameter, without degradation of detector performance. Low power-consuming and compact vacuum UV photosensors that can operate in direct contact with the Scintillation gas, as an alternative to photomultiplier tubes, are now available. Small gettering devices with a low-power built-in heating elements have been shown to be sufficient for the required gas purification in GPSCs assembled with simple and inexpensive techniques, such as the use of epoxies for ceramic-to-metal joints.
A D Stauffer - One of the best experts on this subject based on the ideXlab platform.
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xenon neon gas proportional Scintillation Counters for x rays below 2 kev a monte carlo simulation study
IEEE Transactions on Nuclear Science, 2002Co-Authors: F I G M Borges, F P Santos, T H V T Dias, P J B M Rachinhas, C A N Conde, A D StaufferAbstract:The energy spectra of X-rays with energies below 2 keV measured at atmospheric pressure with standard Xe gas detectors, such as gas proportional-Scintillation Counters, exhibit distortions that are related to losses of electrons and fluorescence photons to the radiation window. In this paper, a Monte Carlo simulation method that takes into account these losses investigates the use of Xe-Ne mixtures as detection media in this energy range. For a total pressure of 1 atm, energy spectra were calculated for nine mixtures with Xe concentrations varying from 10% to 100%. The results have shown that the addition of Ne to Xe significantly reduces distortion and improves the energy resolution of the full energy peaks.
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simulation and experimental results for the detection of conversion electrons with gas proportional Scintillation Counters
Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2000Co-Authors: P J B M Rachinhas, J Dos M F Santos, T H V T Dias, J A M Lopes, P C P S Simoes, A D Stauffer, R E Morgado, C A N CondeAbstract:Abstract The application of gas proportional Scintillation Counters (GPSC) to the detection and identification of conversion electrons in the medium energy range is investigated. Experimental and Monte Carlo results are presented for the response of a xenon GPSC, filled at atmospheric pressure, to the decay of a 109 Cd source. This source emits 88.0 keV γ-rays, e L =84.6 keV and e K =62.5 keV conversion electrons, as well as fluorescence X-rays and Auger electrons. Good agreement is found between the measured and the calculated energy spectra. The response to higher-energy electrons is investigated by Monte Carlo simulation, by considering a hypothetical GPSC filled with xenon at 10 atm and doped with the 133 m Xe metastable isotope. The calculated energy spectra for the absorption of the 133 m Xe 233.2 keV γ-rays, e K =198.6 keV and e L =228.4 keV conversion electrons, as well as fluorescence X-rays and Auger electrons, are presented and discussed.
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xenon neon gas proportional Scintillation Counters experimental and simulation results
Journal of Applied Physics, 1999Co-Authors: T H V T Dias, F I G M Borges, F P Santos, J Dos M F Santos, P J B M Rachinhas, C A N Conde, A D StaufferAbstract:When gas proportional Scintillation Counters (GPSC) are used to detect very low energy x rays, the addition of the light noble gas neon to the usual xenon filling improves the collection of primary electrons that originate near the detector window. However, xenon–neon mixtures have lower electroluminescence yields than pure xenon. Increasing the Scintillation electric field jeopardizes the energy resolution because of the additional fluctuations introduced by electron multiplication. In this work we investigate the effect of a limited amount of charge multiplication on the electroluminescence yield and the energy resolution R of a xenon–neon GPSC using both Monte Carlo simulation and experimental measurements. We consider xenon–neon mixtures with 5%, 10%, 20%, 30%, 40%, 50%, 70%, 90%, and 100% Xe at a total pressure of 800 Torr. Comparing the experimental and Monte Carlo data for 5.9 keV x rays, we conclude that optimum value of R is reached in a region of weak ionization with a charge gain of less than 2...
T H V T Dias - One of the best experts on this subject based on the ideXlab platform.
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xenon neon gas proportional Scintillation Counters for x rays below 2 kev a monte carlo simulation study
IEEE Transactions on Nuclear Science, 2002Co-Authors: F I G M Borges, F P Santos, T H V T Dias, P J B M Rachinhas, C A N Conde, A D StaufferAbstract:The energy spectra of X-rays with energies below 2 keV measured at atmospheric pressure with standard Xe gas detectors, such as gas proportional-Scintillation Counters, exhibit distortions that are related to losses of electrons and fluorescence photons to the radiation window. In this paper, a Monte Carlo simulation method that takes into account these losses investigates the use of Xe-Ne mixtures as detection media in this energy range. For a total pressure of 1 atm, energy spectra were calculated for nine mixtures with Xe concentrations varying from 10% to 100%. The results have shown that the addition of Ne to Xe significantly reduces distortion and improves the energy resolution of the full energy peaks.
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xenon neon gas proportional Scintillation Counters for x rays below 2 kev experimental results
IEEE Nuclear Science Symposium, 2002Co-Authors: F I G M Borges, F P Santos, J Dos M F Santos, T H V T Dias, P J B M Rachinhas, C A N CondeAbstract:The energy spectra of X-rays with energies below 2 keV measured with standard Xe filled gas proportional-Scintillation Counters at atmospheric pressure exhibit a distorted tail toward the low energy region, due to the loss of electrons to the detector entrance window. In this framework, a Monte Carlo simulation study taking into account these losses has previously investigated the use of Xe-Ne mixtures as gas proportional Scintillation Counters (GPSC) fillings. It was shown that the addition of Ne to Xe reduces spectra distortion and improves the overall detector performance. In the present work, we present an experimental study of the performance of a GPSC for different Xe-Ne mixtures and X-ray energies in the 200 to 2000 eV energy range and compare the results with the previously obtained Monte Carlo data.
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development of portable gas proportional Scintillation Counters for x ray spectrometry
X-Ray Spectrometry, 2001Co-Authors: J Dos M F Santos, F P Santos, T H V T Dias, P J B M Rachinhas, J F C A Veloso, J A M Lopes, P C P S Simoes, L Requicha F Ferreira, C A N CondeAbstract:A review on gas proportional Scintillation Counters (GPSCs) is presented. Recent achievements towards the portability of simple, inexpensive and compact GPSCs are discussed. Compensation of solid angle effects with the curved grid technique can be used to produce non-focused GPSCs with medium-sized radiation windows, at least up to 80% of the photosensor active diameter, without degradation of detector performance. Low power-consuming and compact vacuum UV photosensors that can operate in direct contact with the Scintillation gas, as an alternative to photomultiplier tubes, are now available. Small gettering devices with a low-power built-in heating elements have been shown to be sufficient for the required gas purification in GPSCs assembled with simple and inexpensive techniques, such as the use of epoxies for ceramic-to-metal joints.
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simulation and experimental results for the detection of conversion electrons with gas proportional Scintillation Counters
Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2000Co-Authors: P J B M Rachinhas, J Dos M F Santos, T H V T Dias, J A M Lopes, P C P S Simoes, A D Stauffer, R E Morgado, C A N CondeAbstract:Abstract The application of gas proportional Scintillation Counters (GPSC) to the detection and identification of conversion electrons in the medium energy range is investigated. Experimental and Monte Carlo results are presented for the response of a xenon GPSC, filled at atmospheric pressure, to the decay of a 109 Cd source. This source emits 88.0 keV γ-rays, e L =84.6 keV and e K =62.5 keV conversion electrons, as well as fluorescence X-rays and Auger electrons. Good agreement is found between the measured and the calculated energy spectra. The response to higher-energy electrons is investigated by Monte Carlo simulation, by considering a hypothetical GPSC filled with xenon at 10 atm and doped with the 133 m Xe metastable isotope. The calculated energy spectra for the absorption of the 133 m Xe 233.2 keV γ-rays, e K =198.6 keV and e L =228.4 keV conversion electrons, as well as fluorescence X-rays and Auger electrons, are presented and discussed.
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xenon neon gas proportional Scintillation Counters experimental and simulation results
Journal of Applied Physics, 1999Co-Authors: T H V T Dias, F I G M Borges, F P Santos, J Dos M F Santos, P J B M Rachinhas, C A N Conde, A D StaufferAbstract:When gas proportional Scintillation Counters (GPSC) are used to detect very low energy x rays, the addition of the light noble gas neon to the usual xenon filling improves the collection of primary electrons that originate near the detector window. However, xenon–neon mixtures have lower electroluminescence yields than pure xenon. Increasing the Scintillation electric field jeopardizes the energy resolution because of the additional fluctuations introduced by electron multiplication. In this work we investigate the effect of a limited amount of charge multiplication on the electroluminescence yield and the energy resolution R of a xenon–neon GPSC using both Monte Carlo simulation and experimental measurements. We consider xenon–neon mixtures with 5%, 10%, 20%, 30%, 40%, 50%, 70%, 90%, and 100% Xe at a total pressure of 800 Torr. Comparing the experimental and Monte Carlo data for 5.9 keV x rays, we conclude that optimum value of R is reached in a region of weak ionization with a charge gain of less than 2...
P J B M Rachinhas - One of the best experts on this subject based on the ideXlab platform.
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xenon neon gas proportional Scintillation Counters for x rays below 2 kev a monte carlo simulation study
IEEE Transactions on Nuclear Science, 2002Co-Authors: F I G M Borges, F P Santos, T H V T Dias, P J B M Rachinhas, C A N Conde, A D StaufferAbstract:The energy spectra of X-rays with energies below 2 keV measured at atmospheric pressure with standard Xe gas detectors, such as gas proportional-Scintillation Counters, exhibit distortions that are related to losses of electrons and fluorescence photons to the radiation window. In this paper, a Monte Carlo simulation method that takes into account these losses investigates the use of Xe-Ne mixtures as detection media in this energy range. For a total pressure of 1 atm, energy spectra were calculated for nine mixtures with Xe concentrations varying from 10% to 100%. The results have shown that the addition of Ne to Xe significantly reduces distortion and improves the energy resolution of the full energy peaks.
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xenon neon gas proportional Scintillation Counters for x rays below 2 kev experimental results
IEEE Nuclear Science Symposium, 2002Co-Authors: F I G M Borges, F P Santos, J Dos M F Santos, T H V T Dias, P J B M Rachinhas, C A N CondeAbstract:The energy spectra of X-rays with energies below 2 keV measured with standard Xe filled gas proportional-Scintillation Counters at atmospheric pressure exhibit a distorted tail toward the low energy region, due to the loss of electrons to the detector entrance window. In this framework, a Monte Carlo simulation study taking into account these losses has previously investigated the use of Xe-Ne mixtures as gas proportional Scintillation Counters (GPSC) fillings. It was shown that the addition of Ne to Xe reduces spectra distortion and improves the overall detector performance. In the present work, we present an experimental study of the performance of a GPSC for different Xe-Ne mixtures and X-ray energies in the 200 to 2000 eV energy range and compare the results with the previously obtained Monte Carlo data.
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development of portable gas proportional Scintillation Counters for x ray spectrometry
X-Ray Spectrometry, 2001Co-Authors: J Dos M F Santos, F P Santos, T H V T Dias, P J B M Rachinhas, J F C A Veloso, J A M Lopes, P C P S Simoes, L Requicha F Ferreira, C A N CondeAbstract:A review on gas proportional Scintillation Counters (GPSCs) is presented. Recent achievements towards the portability of simple, inexpensive and compact GPSCs are discussed. Compensation of solid angle effects with the curved grid technique can be used to produce non-focused GPSCs with medium-sized radiation windows, at least up to 80% of the photosensor active diameter, without degradation of detector performance. Low power-consuming and compact vacuum UV photosensors that can operate in direct contact with the Scintillation gas, as an alternative to photomultiplier tubes, are now available. Small gettering devices with a low-power built-in heating elements have been shown to be sufficient for the required gas purification in GPSCs assembled with simple and inexpensive techniques, such as the use of epoxies for ceramic-to-metal joints.
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simulation and experimental results for the detection of conversion electrons with gas proportional Scintillation Counters
Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2000Co-Authors: P J B M Rachinhas, J Dos M F Santos, T H V T Dias, J A M Lopes, P C P S Simoes, A D Stauffer, R E Morgado, C A N CondeAbstract:Abstract The application of gas proportional Scintillation Counters (GPSC) to the detection and identification of conversion electrons in the medium energy range is investigated. Experimental and Monte Carlo results are presented for the response of a xenon GPSC, filled at atmospheric pressure, to the decay of a 109 Cd source. This source emits 88.0 keV γ-rays, e L =84.6 keV and e K =62.5 keV conversion electrons, as well as fluorescence X-rays and Auger electrons. Good agreement is found between the measured and the calculated energy spectra. The response to higher-energy electrons is investigated by Monte Carlo simulation, by considering a hypothetical GPSC filled with xenon at 10 atm and doped with the 133 m Xe metastable isotope. The calculated energy spectra for the absorption of the 133 m Xe 233.2 keV γ-rays, e K =198.6 keV and e L =228.4 keV conversion electrons, as well as fluorescence X-rays and Auger electrons, are presented and discussed.
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xenon neon gas proportional Scintillation Counters experimental and simulation results
Journal of Applied Physics, 1999Co-Authors: T H V T Dias, F I G M Borges, F P Santos, J Dos M F Santos, P J B M Rachinhas, C A N Conde, A D StaufferAbstract:When gas proportional Scintillation Counters (GPSC) are used to detect very low energy x rays, the addition of the light noble gas neon to the usual xenon filling improves the collection of primary electrons that originate near the detector window. However, xenon–neon mixtures have lower electroluminescence yields than pure xenon. Increasing the Scintillation electric field jeopardizes the energy resolution because of the additional fluctuations introduced by electron multiplication. In this work we investigate the effect of a limited amount of charge multiplication on the electroluminescence yield and the energy resolution R of a xenon–neon GPSC using both Monte Carlo simulation and experimental measurements. We consider xenon–neon mixtures with 5%, 10%, 20%, 30%, 40%, 50%, 70%, 90%, and 100% Xe at a total pressure of 800 Torr. Comparing the experimental and Monte Carlo data for 5.9 keV x rays, we conclude that optimum value of R is reached in a region of weak ionization with a charge gain of less than 2...