Browsing by Author "Gonzalez-Diaz, D."

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Charged particle timing at sub-25 picosecond precision: The picosec detection concept
(Elsevier, 2019-08-21) Iguaz, F. J.; Bortfeldt, J.; Brunbauer, F. M.; David, C.; Desforge, D.; Fanourakis, G.; Franchi, J.; Gallinaro, M.; Garcia, F.; Giomataris, I; Gonzalez-Diaz, D.; Gustaysson, T.; Guyot, C.; Kebbiri, M.; Legou, P.; Liu, J.; Lupberger, M.; Maillard, O.; Manthos, I; Mueller, H.; Niaouris, V; Oliveri, E.; Papaevangelou, T.; Paraschou, K.; Pomorskif, M.; Qi, B.; Resnati, F.; Ropelewski, L.; Sampsonidis, D.; Schneider, T.; Schwemling, P.; Sohl, L.; van Stenis, M.; Thuiner, P.; Tsipolitis, Y.; Tzamarias, S. E.; Wang, X.; White, S.; Zhang, Z.; Zhou, Y.; Veenhof, Rob; Bursa Uludağ Üniversitesi/Fen Edebiyat Fakültesi/Fizik Bölümü.
The PICOSEC detection concept consists in a "two-stage" Micromegas detector coupled to a Cherenkov radiator and equipped with a photocathode. A proof of concept has already been tested: a single-photoelectron response of 76 ps has been measured with a femtosecond UV laser at CEA/IRAMIS, while a time resolution of 24 ps with a mean yield of 10.4 photoelectrons has been measured for 150 GeV muons at the CERN SPS H4 secondary line. This work will present the main results of this prototype and the performance of the different detector configurations tested in 2016-2018 beam campaigns: readouts (bulk, resistive, multipad) and photocathodes (metallic+CsI, pure metallic, diamond). Finally, the prospects for building a demonstrator based on PICOSEC detection concept for future experiments will be discussed. In particular, the scaling strategies for a large area coverage with a multichannel readout plane, the R&D on solid converters for building a robust photocathode and the different resistive configurations for a robust readout.
Modelling the behaviour of microbulk Micromegas in xenon/trimethylamine gas
(Elsevier, 2015-08-22) Ruiz-Choliz, E.; Gonzalez-Diaz, D.; Diago, A.; Castel, J.; Dafni, T.; Herrera, D. C.; Iguaz, F. J.; Irastorza, I. G.; Luzon, G.; Mirallas, H.; Sahin, O.; Veenhof, R.; Uludağ Üniversitesi/Fen Edebiyat Fakültesi/Fizik Bölümü.; 0000-0003-3940-7222; AAH-6445-2021; GJK-8031-2022; 36053592700; 6603742499
We model the response of a state of the art micro-hole single-stage charge amplification device ('microbulk' Micromegas) in a gaseous atmosphere consisting of xenon/trimethylamine at various concentrations and pressures. The amplifying structure, made with photo-lithographic techniques similar to those followed in the fabrication of gas electron multipliers (GEMs), consisted of a 100 mu m-side equilateral-triangle pattern with 50 pm-diameter holes placed at its vertexes. Once the primary electrons are guided into the holes by virtue of an optimized field configuration, avalanches develop along the 50 [an-height channels etched out of the original doubly copper-clad polyimide foil. In order to properly account for the strong field gradients at the holes' entrance as well as for the fluctuations of the avalanche process (that ultimately determine the achievable energy resolution), we abandoned the hydrodynamic framework, resorting to a purely microscopic description of the electron trajectories as obtained from elementary cross-sections. We show that achieving a satisfactory description needs additional assumptions about atom-molecule (Penning) transfer reactions and charge recombination to be made.
Progress on the PICOSEC-micromegas detector development: Towards a precise timing, radiation hard, large-scale particle detector with segmented readout
(Elsevier, 2020-04-01) Kordas, K.; Bortfeldt, J.; Brunbauer, F.; David, C.; Desforge, D.; Fanourakis, G.; Franchi, J.; Gallinaro, M.; Garcia, F.; Giomataris, I.; Gonzalez-Diaz, D.; Gustavsson, T.; Guyot, C.; Iguaz, F. J.; Kebbiri, M.; Legou, P.; Liu, J.; Lupberger, M.; Maillard, O.; Maniatis, I.; Manthos, I.; Mueller, H.; Niaouris, V.; Oliveri, E.; Papaevangelou, T.; Paraschou, K.; Pomorski, M.; Qi, B.; Resnati, F.; Ropelewski, L.; Sampsonidis, D.; Schneider, T.; Schwemling, P.; Sohl, L.; van Stenis, M.; Thuiner, P.; Tsipolitis, Y.; Tzamarias, S. E.; Veenhof, R.; Wang, X.; White, S.; Zhang, Z.; Zhou, Y.; Veenhof, Rob; Bursa Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Fizik Bölümü.; GJK-8031-2022
This contribution describes the PICOSEC-Micromegas detector which achieves a time resolution below 25 ps. In this device the passage of a charged particle produces Cherenkov photons in a radiator, which then generate electrons in a photocathode and these photoelectrons enter a two-stage Micromegas with a reduced drift region and a typical anode region. The results from single-channel prototypes (demonstrating a time resolution of 24 ps for minimum ionizing particles, and 76 ps for single photoelectrons), the understanding of the detector in terms of detailed simulations and a phenomenological model, the issues of robustness and how they are tackled, and preliminary results from a multi-channel prototype are presented (demonstrating that a timing resolution similar to that of the single-channel device is feasible for all points across the area covered by a multi-channel device).