20.500.12556/RUL-188892 Development of timing detectors for future experiments in particle physics Razvoj detektorjev časa za bodoče experimente v fiziki delcev This thesis presents an investigation into the design and operation of LGAD detectors within the HGTD framework in preparation for the upgrade of the LHC to HL-LHC. Samples from various manufacturers were measured and characterised using CV/IV, timing and collected charge measurements both before and after irradiation with reactor neutrons. In terms of design, it is clear that a high doping concentration of boron results in a lower removal constant, as does the addition of carbon up to a certain point. The affect of annealing and neutron flux was investigated in order to determine an operating plan for HGTD. It was found that the performance was not largely affected by either. The affect of floating pads on the remaining connected pads was studied using 2x2 arrays with varying inter-pad gaps. As expected, a smaller inter-pad gap leads to early breakdown and punch-through occurring at a lower bias. A new setup was designed to test the long term stability of sensors under high biases. Overall the samples proved to be very robust in laboratory tests. However, destructive breakdown of irradiated sensors has been observed when operated at high biases in a high energy particle beam. Samples were sent to two test beam campaigns. It was determined that these destructive breakdowns occur when the average electric field in the sensor goes beyond 12 V/$\mu$m. In order to simulate LGADs, the impact ionization parameters for silicon needed to be determined. The dependence of the parameters on temperature was also determined. Their validity was then tested using measurements from irradiated sensors up to $2.5\cdot10^{15}$ cm$^{-2}$ and it was found that they were acceptable at low biases. Ta disertacija predstavlja raziskavo zasnove in delovanja detektorjev LGAD v okviru HGTD v pripravah na nadgradnjo LHC na HL-LHC. Vzorci različnih proizvajalcev so bili izmerjeni in karakterizirani z uporabo CV/IV, časovne meritve in meritev zbranega naboja pred in po obsevanju z reaktorskimi nevtroni. Kar zadeva zasnovo, je jasno, da visoka koncentracija dopiranja bora povzroči nižjo konstanto odstranjevanja, prav tako pa tudi dodajanje ogljika do določene točke. Za določitev operativnega načrta za HGTD je bil raziskan vpliv žarjenja in nevtronskega toka. Ugotovljeno je bilo, da na delovanje ni bistveno vplivalo nič od tega. Vpliv plavajočih blazinic na preostale povezane blazinice je bil proučen z uporabo nizov 2x2 z različnimi razmiki med blazinicami. Kot je bilo pričakovano, manjša razmik med blazinicami vodi do zgodnjega preboja in preboja pri nižji prednapetosti. Zasnovana je bila nova postavitev za testiranje dolgoročne stabilnosti senzorjev pri visokih prednapetostih. Na splošno so se vzorci v laboratorijskih testih izkazali za zelo robustne. Vendar pa je bila opažena destruktivna razgradnja obsevanih senzorjev pri delovanju pri visokih prednapetostih v visokoenergijskem žarku delcev. Vzorci so bili poslani v dve kampanji testnih žarkov. Ugotovljeno je bilo, da do teh destruktivnih razgradenj pride, ko povprečno električno polje v senzorju preseže 12 V/$\mu$m. Za simulacijo LGAD-ov je bilo treba določiti parametre udarne ionizacije za silicij. Določena je bila tudi odvisnost parametrov od temperature. Njihova veljavnost je bila nato preizkušena z meritvami iz obsevanih senzorjev do $2.5\cdot10^{15}$ cm$^{-2}$ in ugotovljeno je bilo, da so sprejemljivi pri nizkih pristranskostih. ATLAS HGTD LHC silicon detectors radiation damage radiation hard detectors timing detectors low gain avalanche detector acceptor removal impact ionization ATLAS HGTD LHC silicijevi detektorji poškodbe zaradi sevanja trdi detektorji sevanja časovni detektorji detektor plazov z nizkim ojačanjem odstranitev akceptorja udarna ionizacija true false false Angleški jezik Slovenski jezik Doktorsko delo/naloga 2026-09-30 08:15:07 2026-09-30 08:15:15 2026-10-05 13:51:14 0000-00-00 00:00:00 2026 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 165747 293701379 24778.pdf 24778.pdf 1 9575DA3A6F3C69D2C84CC7952457FBAB b059987f2b6a97abe53031aba06e40096af6184361851578eba19d9eea3347fb 36f7233a-bc96-11f1-8bc5-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=249275 Fakulteta za matematiko in fiziko 0 0 0