Ph.d. degree
Weizmann Institute of Science, Israel, 2022

Dan Shaked-Renous

Supervisor: Shikma Bressler

Investigation of RPWELL-based Digital Hadronic Calorimeter

Keywords:

• Micropattern gaseous detectors (MSGC, GEM, THGEM, RETHGEM, MHSP, MICROPIC, MICROMEGAS, InGrid, etc); Calorimeters
• Simulation methods and programs

Abstract:

In search for beyond the standard model of physics, the foreseen program of the high-energy physics community relies on precision measurements of the Higgs, W, and Z bosons, also in their hadronic decay modes. Thus, future collider experiments would need jet energy resolution superior to the one measured in today’s state-of-the-art experiments. Particle flow, i.e., the measurement of each particle separately, is one of the leading approaches studied in this context. It requires high granular detectors and, among others, motivates the development of digital hadronic calorimeter (DHCAL). The DHCAL concept was mostly studied with sampling elements based on Resistive Plate Chambers (RPC). However, recent studies focusing on sampling elements based on Micro-Pattern Gaseous Detector (MPGD) have shown their potential advantages compared to the RPC.
The presented thesis is a part of an ongoing R&D effort towards a particle flow DHCAL based on the Resistive Plate WELL (RPWELL) detector. Our group at WIS has already demonstrated that RPWELL- based sampling elements could meet the DHCAL requirements. It was operated with an environment-friendly gas mixture in test beams of muons and high-rate pion beam, demonstrating 1.1 average pad- multiplicity at 98% MIP detection efficiency in discharge-free conditions.
In this work, we developed, built, and tested the first large (50×50 cm^2) RPWELL detector with full coverage (no dead area in the gas volume). After demonstrating the effective coupling of the RPWELL to a semi-digital readout system, we could operate the first small MPGD-based DHCAL prototype. This prototype, comprising RPWELL- and Micromegas based-sampling elements, was tested in low energy (2–6 GeV) pion beam; the collected data enabled validating a GEANT4-based DHCAL simulation framework that we developed.
Using that simulation framework, we estimated the expected performance of a 50-layers RPWELL- based DHCAL module. It was tested with pions at the energy of 6-36 GeV, yielding a relative pion energy resolution of \frac{\sigma}{E[GeV]}= \frac{(50.8 ± 0.3)\%}{\sqrt{E[GeV]}} \oplus (10.3 ± 0.06)\%, assuming 98% MIP detection efficiency and 1.1 average pad-multiplicity. Thus, suggesting that an optimal RPWELL-based DHCAL could enable the targeted jet-energy resolution using particle flow calorimetry.