Irradiation Studies of Cherenkov Radiators for Use in Zero Degree Calorimeters and Reaction Plane Detectors During the High Luminosity LHC Era

At the frontier of nuclear physics is our quest to more deeply understand the strong nuclear force — Quantum Chromodynamics (QCD) and in particular properties of nuclear matter under the hottest, densest conditions in our QCD laboratory. To do so is a complex undertaking composed of many measurements from many particle detectors that record high energy particle collisions. To concentrate on the hottest and densest matter, we focus on the collisions of ultra—relatiVistic Heavy Ions (HI). This research project will develop a new radiation hard Reaction Plane Detector, RPD, for the ATLAS and CMS experiments in the High Luminosity LHC, the most powerful particle accelerator in the world. The detectors will be used together with the Zero Degree Calorimeters (ZDC) to characterize the event geometry in HI collisions. Understanding the geometry of the collision is key to understanding the bulk properties of the Quark Gluon Plasma — a nuclear matter that is distinct from the phases of matter we usually consider on macroscopic scales. In addition, and in some sense even more fundamentally, these detectors are crucial for almost all HI measurements by identifying relevant collisions and triggering the data acquisition systems of the experiment.

The detectors work by measuring Cherenkov light — photons produced by highly energetic particles traversing a di—electric material. The basic problem is devising a robust two—dimensional Cherenkov light detector that is radiation hard to an unprecedented degree. A comprehensive regimen of radiation testing of each detector component using neutron and gamma sources at the Soreq Nuclear Research Center will proceed in parallel with tests of light production and transmission measurements at the Frederick Seitz Materials Research Laboratory. The project will culminate with a final radiation—hard RPD design integrated into the ZDC for both ATLAS and CMS.

This project will engage undergraduate and graduate students at all collaborating institutions and they will be involved in both physics studies and in R&D of radiation—hard instrumentation. This project is a continuation of collaborative work between UIUC and BGU over the last few years which has laid the groundwork for the RPD and ZDC detector development.