Encontrados 15 documentos, a visualizar página 1 de 2
A concise review on THGEM detectors
Breskin, A.; Alon, R.; Cortesi, M.; Chechik, R.; Miyamoto, J.; Dangendorf, V.; Maia, J. M.; Santos, J. M. F. doshttp://www.sciencedirect.com/science/article/B6TJM-4T8JX8Y-1/2/691894558a313c30f6e8cdb7cf598b67
Efficient ion blocking in gaseous detectors and its application to gas-avalanch...
Lyashenko, A.; Breskin, A.; Chechik, R.; Santos, J. M. F. dos; Amaro, F. D.; Veloso, J. F. C. A.http://www.sciencedirect.com/science/article/B6TJM-4T8HH99-2/2/f970f5561a88e355e57ce6de077a59fa
The Photon-Assisted Cascaded Electron Multiplier Operation in CF _4 for Ion Ba...
Amaro, F. D.; Veloso, J. F. C. A.; Santos, J. M. F. dos; Breskin, A.; Chechik, R.; Lyashenko, A.The operation of the recently introduced photon assisted cascaded electron multiplier (PACEM) in CF4 is investigated. The PACEM uses the VUV scintillation produced in the electron avalanches of the first multiplier of the cascade to transfer the signal to the subsequent ones. The VUV scintillation induces the emission of a large number of photoelectrons from a Csl photocathode placed on the top-surface of the s...
Measurement of the photoelectron-collection efficiency in noble gases and methane
Coelho, L. C. C.; Ferreira, H. M. N. B. L.; Lopes, J. A. M.; Dias, T. H. V. T.; Ferreira, L. F. R.; Santos, J. M. F. dos; Breskin, A.; Chechik, R.The photoelectron-collection efficiency from photocathodes in noble gases and methane is experimentally investigated. The ratio between the number of transmitted photoelectrons in the gas media and in vacuum is determined as a function of the applied reduced electric field E/p, where p is the gas pressure. Results are presented for He, Ne, Ar, Xe, Kr and CH4. ; http://www.sciencedirect.com/science/article/B6...
PACEM: a new concept for high avalanche-ion blocking
Veloso, J. F. C. A.; Amaro, F. D.; Azevedo, C. D. R.; Santos, J. M. F. dos; Breskin, A.; Lyashenko, A.; Chechik, R.We present the Photon-Assisted Cascaded Electron Multiplier (PACEM) as a potential alternative for ion back-flow suppression in gaseous cascade electron multipliers. Using a Micro Hole and Strip Plate-Gas Electron Multiplier (MHSP-GEM) configuration, the number of ions flowing back to the scintillation region is about 1.5 ions per primary electron at an optical gain of 6.5 and a drift field of 0.1 kV/cm, and ab...
Micro-hole and strip plate-based photosensor
Freitas, E. D. C.; Veloso, J. F. C. A.; Breskin, A.; Chechik, R.; Amaro, F. D.; Ferreira, L. F. Requicha; Maia, J. M.; Santos, J. M. F. dosThe performance of a new VUV photosensor, based on an micro-hole and strip plate (MHSP) electron multiplier with a CsI photocathode deposited on its top electrode, is described. This photosensor presents gains above 104 when operating in an Ar-5%Xe gas mixture at 1 atm. Although the gain of a single MHSP is not sufficient for efficient detection of single photons, this simple UV photosensor may be useful for th...
High-rate operation of the Micro-Hole and Strip Plate gas detector
Veloso, J. F. C. A.; Caldas, C. C.; Oliveira, C. A. B.; Azevedo, C. D. R.; Santos, J. M. F. dos; Breskin, A.; Chechik, R.We report the performance of the Micro-Hole-and-Strip-Plate (MHSP) operated in xenon, under high-flux irradiation of a 30-kV X-ray Cu-tube. Stable operation in pulse-counting mode for gas gains above 104 was measured up to counting rates of 5×105 Hz/mm2. A gain variation of less than 5% was observed for gains of 104, while the energy resolution for 8-keV X-rays degrades from ~16% to ~18%. No visible degradation...
Single-UV-photon 2-D imaging with multi-GEM detectors
Maia, J. M.; Mörmann, D.; Breskin, A.; Chechik, R.; Veloso, J. F. C. A.; Santos, J. M. F. dosThe main goal being the construction of large-area, low-cost position-sensitive micropattern gaseous photomultipliers (GPMs) based on gas electron multipliers (GEM) cascades, we have studied the single-photon imaging capabilities of a 4-GEM GPM with a reflective CsI-photocathode deposited on the top surface of the 1st GEM. The charge readout was performed with a simple/economic Wedge and Strip (W&S) readout ele...
Ion-induced effects in GEM and GEM/MHSP gaseous photomultipliers for the UV and...
Breskin, A.; Mörmann, D.; Lyashenko, A.; Chechik, R.; Amaro, F. D.; Maia, J. M.; Veloso, J. F. C. A.; Santos, J. M. F. dosWe report on the progress in the study of cascaded GEM and GEM/MHSP gas avalanche photomultipliers operating at atmospheric pressure, with CsI and bialkali photocathodes. They have single-photon sensitivity, ns time resolution and good localization properties. We summarize operational aspects and results, with the highlight of a high-gain stable gated operation of a visible-light device. Of particular importanc...
MHSP operation in pure xenon
Luz, H. Natal da; Veloso, J. F. C. A.; Amaro, F. D.; Ferreira, L. F. Requicha; Santos, J. M. F. dos; Breskin, A; Chechik, R.We present latest results of a micro-hole and strip plate (MHSP) electron multiplier operating in pure xenon at atmospheric pressure. We report on avalanche gain of ~2×104, stable within ~3% after an accumulated charge of 4 [mu]C/mm2, when irradiated with 0.5 kHz/mm2 5.9 keV photons. No photon-induced secondary effects or discharges have been observed at this gain. An energy resolution of 14% was obtained with ...
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