Nanodiamond photocathodes for MPGD-based single photon detectors at future EIC

We are developing gaseous photon detectors for Cherenkov imaging applications inthe experiments at the future Electron Ion Collider. CsI, converting photons in the far ultravioletrange, is, so far, the only photoconverter compatible with the operation of gaseous detectors. It isvery delicate to handle due to its hygroscopic nature: the absorbed water vapour decomposes theCsI molecule. In addition, its quantum efficiency degrades under ion bombardment. These arethe key reasons to quest for novel, less delicate materials for photocathodes adequate for gaseousphoton detectors. Layers of hydrogenated nanodiamond particles have recently been proposed as an alternative material and have shown promising characteristics. The performance of nanodiamondphotocathodes coupled to thick GEM-based detectors is the objects of our ongoing R&D.The first phase of these studies includes the characterization of thick GEM coated with nanodiamondlayers and the robustness of its photoconverting properties with respect to the bombardmentby ions from the multiplication process in the gaseous detector.The approach is described in detail as well as all the results obtained so far within theseexploratory studies.