Karakterizacija detektorskih modulov za spremljanje protonskih curkov za nadgradnjo sledilnika spektrometra ATLAS

Mali, Miha (author), Mikuž, Marko (mentor), Gorišek, Andrej (comentor)

Cilj naloge je karakterizacija detektorskih modulov z nameščenim bralnim čipom Calypso. Bralni čip je zasnovan kot del detektorskega sistema BCM', ki je namenjen spremljanju protonskih curkov v nadgrajenem spektrometru ATLAS. Nadgradnja je potrebna zaradi povečanja zmogljivosti detektorjev za zaznavanje delcev in za povečanje njihove odpornosti na sevanje. Čip Calypso je zgrajen v sevalno odporni 65 nm CMOS tehnologiji in ima štiri kanale, ki so povezani na diamantni senzor. Vsak kanal ima en analogni in dva diferencialna izhoda z informacijo o času nad pragom in času prihoda signala. Da bi ovrednotili odpornost na sevanje, sta bila v laboratoriju testirana dva neobsevana čipa in dva obsevana čipa. Čipi so bili nameščeni na testne detektorske module, ki omogočajo laboratorijsko testiranje z zunanjim pulzerjem. Pri obsevanih čipih je opažen premik osnovnice in rahlo povečanje šuma analognega izhodnega signala. Po obsevanju opazimo povečanje razlike med ojačanji signala. Pri vseh čipih je odvisnost časa nad pragom diferencialnih signalov od višine analognega signala linearna, za celoten spekter nastavitev diskriminatorja. Neobsevan detektorski modul z nameščenim pCVD diamantom je bil testiran s stroncijem-90 kot virom delcev MIP. Testirane so bile različne visoke napetosti na diamantnem senzorju, natančneje napetosti -1000 V, -500 V, -200 V in +1000 V. Izmerjeno razmerje signal/šum pri napetosti -1000 V znaša 14.9, z nižanjem napetosti pa se signal in razmerje signal/šum zmanjšata.

• Language: Slovenian
• Keywords: nadgradnja spektrometra ATLAS, nadziranje pogojev protonskega curka, BCM, čip Calypso, diamantni detektor, vplivi sevanja, meritve delcev MIP
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FMF - Faculty of Mathematics and Physics
• Year: 2021
• PID: 20.500.12556/RUL-130530
• COBISS.SI-ID: 76486403
• Publication date in RUL: 16.09.2021

Secondary language

• Language: English
• Title: Detector Module Characterization of the Beam Conditions Monitor for the ATLAS Tracker Upgrade

Abstract

The goal of the thesis is the characterization of the detector modules with installed Calypso ASICs. Calypso ASIC is part of the BCM' detector system, intended for monitoring the proton beam conditions of the upgraded ATLAS detector. ATLAS upgrades are necessary for increasing the capabilities of particle detection and for increasing the radiation tolerance of the detectors. Calypso ASIC is built in 65 nm technology and contains 4 channels, which are connected to the diamond sensor. Each channel has an analog output and two differential outputs, which carry the signal Time-over-Threshold and Time-of-Arrival information. To characterize the radiation tolerance, laboratory tests were conducted on two reference chips and two irradiated chips. The selected chips were mounted on detector modules, which serve as a test platform for laboratory tests with an external pulser. Baseline shifts and a slight noise increase in analog signals are observed in irradiated chips. Irradiated chips show an increase of spread in gain of the amplifer chain. The pulse length of Time-over-Threshold differential outputs of all tested chips show linear dependence on the analog signal across the entire range of discriminator threshold settings. An unirradiated test module with installed pCVD diamond was tested using Sr-90 as a source of MIP particles. High voltages of -1000 V, -500 V, -200 V and +1000 V were applied to the diamond sensor. The signal-to-noise ratio measured at -1000 V is 14.9 Both signal and S/N ratio decrease at lower voltages.

• Keywords: ATLAS upgrade, proton beam conditions monitoring, BCM, Calypso ASIC, diamond detector, radiation effects, MIP measurements