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The X-ray performance of a driftless gas proportional scintillation counter usi...
Covita, D. S.; Simões, P. C. P. S.; Fernandes, L. M. P.; Freitas, E. D. C.; Ferreira, L. F. Requicha; Veloso, J. F. C. A.; Santos, J. M. F. dosPerformance characteristics are evaluated for a xenon driftless gas proportional scintillation counter (GPSC), for which detector pulses are formatted using very short shaping-time constants (~50 ns), and directly analyzed by the MCA without previous pulse time duration analysis and amplitude correction. The present detector and method allow the achievement of detector energy linearity and energy resolution sim...
Energy non-linearity effects in argon gaseous detectors in the region of the Ar...
Monteiro, C. M. B.; Simões, P. C. P. S.; Veloso, J. F. C. A.; Santos, J. M. F. dos; Conde, C. A. N.The response of an argon proportional counter to X-rays with energy in the range of 1.5-8 keV was investigated. The response to full-energy absorption events was found to follow different trends for X-ray energies below and above the argon K-absorption edge presenting a discontinuity at this energy. An abrupt decrease of (2.2±0.3)% in the detector amplitude at the K-edge (3.203 keV) was measured, corresponding ...
A new method for pulse analysis of driftless-gas proportional scintillation cou...
Simões, P. C. P. S.; Covita, D. S.; Veloso, J. F. C. A.; Santos, J. M. F. dos; Morgado, R. E.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 [mu]s), the use of very short linear amplifier...
Digital rise-time discrimination of large-area avalanche photodiode signals in ...
Fernandes, L. M. P.; Simões, P. C. P. S.; Santos, J. M. F. dos; Morgado, R. E.Large-area 1.9-keV X-ray detectors operating in magnetic fields up to 5 T are required for the μp-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...
Driftless gas proportional scintillation counter pulse analysis using digital p...
Simões, P. C. P. S.; Santos, J. M. F. dos; Conde, C. A. N.A driftless gas proportional scintillation counter (GPSC) of simple design, using digital pulse-signature analysis, is described. The digital pulse acquisition and processing techniques are shown to be a simple and effective method to determine pulse time duration and to perform pulse amplitude correction in driftless GPSCs. This technique allows the application of driftless GPSCs to x-ray spectrometry up to 60...
Development of portable gas proportional scintillation counters for x-ray spect...
Santos, J. M. F. dos; Lopes, J. A. M.; Veloso, J. F. C. A.; Simões, P. C. P. S.; Dias, T. H. V. T.; Santos, F. P.; Rachinhas, P. J. B. M.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 performa...
Simulation and experimental results for the detection of conversion electrons w...
Rachinhas, P. J. B. M.; Simões, P. C. P. S.; Lopes, J. A. M.; Dias, T. H. V. T.; Morgado, R. E.; Santos, J. M. F. dos; Stauffer, A. D.; Conde, C. A. N.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 109Cd source. This source emits 88.0 keV [gamma]-rays, eL=84.6 keV and eK=62.5 keV conversion electrons, as w...
Gas proportional scintillation counter pulse-signature analysis using digital t...
Simões, P. C. P. S.; Santos, J. M. F. dos; Conde, C. A. N.The use of short shaping time-constants (50 ns) followed by digital sampling of gas proportional scintillation counter pulses is investigated. Such short shaping time causes each pulse to closely resemble the scintillation light burst, allowing for an effective pulse-signature analysis. Pulse amplitude is obtained by numerical integration of the digital pulse samples. The shorter total pulse durations, lead to ...
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