arXiv subjects

T. Ligonzo

Publications and source records attributed to T. Ligonzo.

4 recordsLinked to original sources

arXiv2025

Nanodiamond photocathodes for MPGD-based single photon detectors

This study investigates the suitability of Hydrogenated NanoDiamond (HND) materials as an alternative for CsI in MPGD-based photon detectors. The research focuses on characterizing HND photocathodes coupled with THGEM + Micromegas-based detectors. The HND grains were prepared via hydrogenation and stored in water for more than two years. They were then coated on PCB discs or THGEMs using a pulsed spray technique. The resulting quantum efficiency (QE) values (~4% at 122 nm) were found to be within a factor of 10 of the best freshly hydrogenated samples reported in the literature ( ~40% at 120 nm). The robustness of reflective HND photocathodes against ion bombardment was measured to be about 10 times larger than the corresponding CsI one after the same charge accumulation. Furthermore, THGEM characterization indicates minimal alteration in response after HND coatings. These results suggest that HND holds potential as a more robust photocathode for gaseous detectors, offering improved performance in single-photon detection applications.

physics.ins-det↗

arXiv2024

Study of nanodiamond photocathodes for MPGD-based detectors of single photons

The proposed new Electron-Ion Collider poses a technical and intellectual challenge for the detector design to accommodate the long-term diverse physics goals envisaged by the program. This requires a 4π detector system capable of reconstructing the energy and momentum of final state particles with high precision. The Electron-Ion Collider also requires identification of particles of different masses over a wide momentum range. A diverse spectrum of Particle Identification detectors has been proposed. Of the four types of detectors for hadron identification, three are based on Ring Imaging Cherenkov Counter technologies, and one is realized by the Time of Flight method. The quest for a novel photocathode, sensitive in the far vacuum ultra violet wavelength range and more robust than cesium iodide, motivated an R&D programme to explore nano-diamond (ND) based photocathodes, started by a collaboration between INFN and CNR Bari and INFN Trieste. Systematic measurements of the photo emission in different Ar-CH4 and Ar-CO2 gas mixtures with various types of ND powders and Hydrogenated ND (H-ND) powders are reported. A first study of the response of THGEMs coated with different photocathode materials is presented. The progress of this R&D programme and the results obtained so far by these exploratory studies are described.

physics.ins-det↗

arXiv2024

Progress in coupling MPGD-based Photon Detectors with Nanodiamond Photocathodes

The next generation of gaseous photon detectors is requested to overcome the limitations of the available technology, in terms of resolution and robustness. The quest for a novel photocathode, sensitive in the far vacuum ultra violet wavelength range and more robust than present ones, motivated an R&D programme to explore nanodiamond based photoconverters, which represent the most promising alternative to cesium iodine. A procedure for producing the novel photocathodes has been defined and applied on THGEMs samples. Systematic measurements of the photo emission in different Ar/CH4 and Ar/CO2 gas mixtures with various types of nanodiamond powders have been performed. A comparative study of the response of THGEMs before and after coating demonstrated their full compatibility with the novel photocathodes.

physics.ins-det↗

arXiv2020

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

We are developing gaseous photon detectors for Cherenkov imaging applications in the experiments at the future Electron Ion Collider. CsI, converting photons in the far ultraviolet range, is, so far, the only photoconverter compatible with the operation of gaseous detectors. It is very delicate to handle due to its hygroscopic nature: the absorbed water vapour decomposes the CsI molecule. In addition, its quantum efficiency degrades under ion bombardment. These are the key reasons to quest for novel, less delicate materials for photocathodes adequate for gaseous photon detectors. Layers of hydrogenated nanodiamond particles have recently been proposed as an alternative material and have shown promising characteristics. The performance of nanodiamond photocathodes coupled to thick GEM-based detectors is the object of our ongoing R\&D. The first phase of these studies includes the characterization of thick GEM coated with nanodiamond layers and the robustness of its photoconverting properties with respect to the bombardment by 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 these exploratory studies.

physics.ins-det↗