magistrsko delo
Jernej Debevc (Author), Igor Mandić (Mentor), Bojan Hiti (Co-mentor)

Abstract

V magistrskem delu so preučene časovne lastnosti prototipnega polprevodniškega detektorja delcev RD50-MPW2. Obravnavani prototip je zasnovan kot monolitni detektor v depletirani CMOS tehnologiji. Monolitni princip se ponuja kot alternativa ustaljeni hibridni tehnologiji izdelave detektorjev in prinaša številne prednosti, kot so boljša natančnost sledenja pri manjši končni količini materiala v detektorju ter hitrejša in cenejša izdelava zaradi uporabe standardnih industrijskih CMOS procesov. Zaradi teh koristi je bila možnost uporabe monolitnih detektorjev obravnavana za prihajajočo nadgradnjo sledilnega sistema eksperimenta ATLAS, prizadevanja za razvoj tehnologije pa se nadaljujejo tudi za prihodnje potrebe eksperimentov v fiziki osnovnih delcev. Meritve predstavljene v tem delu so osredotočene na karakterizacijo časovne ločljivosti aktivnih blazinic prototipa v odvisnosti od količine zbranega naboja. Časovna ločljivost je bila določena z uporabo novih metod z različnimi načini generacije naboja na vhodu bralne elektronike blazinic: z metodo E-TCT z uporabo sunkov infrardeče laserske svetlobe in elektroni iz radioaktivnega vira $^{90}\mathrm{Sr}$. Vplivi sevalnih poškodb na časovno ločljivost so bili preučeni z meritvami vzorca obsevanega z reaktorskimi nevtroni do ekvivalentne fluence $5\cdot 10^{14}~\mathrm{n_{eq}/cm^2}$. Rezultati meritev kažejo, da je časovna ločljivost prototipa RD50-MPW2 v skladu s pričakovanji in znaša približno $300~\mathrm{ps}$. Glavni prispevek k časovni ločljivosti predstavlja šum elektronike, nekaj prispevajo še efekti med fazo zbiranja naboja v siromašenem območju. Pri meritvah z metodo E-TCT po obsevanju ni sprememb v časovni ločljivosti, medtem ko meritve s $^{90}\mathrm{Sr}$ kažejo občutno izboljšanje ločljivosti po obsevanju, kar je najverjetneje posledica zbiranja naboja iz neosiromašenega področja preko počasnejšega procesa difuzije v neobsevanem vzorcu.

Keywords

fizika osnovnih delcev;silicijevi detektorji delcev;monolitni detektorji;CMOS;časovne lastnosti;sevalne poškodbe;eksperiment ATLAS;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL FMF - Faculty of Mathematics and Physics
Publisher: [J. Debevc]
UDC: 539.1.074
COBISS: 120962563 Link will open in a new window
Views: 37
Downloads: 11
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Other data

Secondary language: English
Secondary title: Measurements of timing properties of a CMOS charged particle detector
Secondary abstract: This master's thesis presents studies of timing properties of the RD50-MPW2 prototype silicon particle detector, which is designed as a monolithic detector using depleted CMOS technology. A monolithic design is an alternative to the well-established hybrid technology, offering many additional benefits, the main being better tracking performance at a lower overall material budget and reduced cost and time of production. These advantages have led the ATLAS collaboration to consider the use of monolithic detectors in the new tracking system, scheduled to be installed during the next upgrade of the experiment. Further research and development efforts focused on improving the technology for future needs of particle physics experiments are in progress as well. Measurements presented in this work focus on the characterization of timing resolution of the prototype's active pixels and its dependence on the amount of collected charge. The timing resolution was measured in a new way using different methods of generating charge in front of the readout electronics: with the E-TCT technique using pulsed infrared laser light and electrons from a radioactive $^{90}\mathrm{Sr}$ source. Effects of radiation damage on timing resolution have been studied by measuring a sample irradiated with reactor neutrons to an equivalent fluence of $5\cdot 10^{14}~\mathrm{n_{eq}/cm^2}$. The obtained results show a timing resolution of approximately $300~\mathrm{ps}$, which is within expectations for this prototype. The main contribution to the timing resolution is the jitter of the electronics, with minor contributions coming from effects in the charge collection phase. E-TCT measurements show no increase in the timing resolution after irradiation, whereas in $^{90}\mathrm{Sr}$ measurements, the timing resolution improved in the irradiated sample, which is most likely a consequence of slower collection of charge from the undepleted regions of the pixel via diffusion in the unirradiated sample.
Secondary keywords: physics of elementary particles;silicon particle detectors;monolithic detectors;CMOS;timing properties;radiation damage;ATLAS experiment;
Type (COBISS): Master's thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Fak. za matematiko in fiziko, Oddelek za fiziko
Pages: 74 str.
ID: 16439146