Paper

Measurements of a LYSO crystal array from threshold to 100 MeV

Ding, D, Soter, A, Hui, J, Beesley, O, Davis-Purcell, B, Hochrein, S, Foster, S, Liu, J, Gibbons, L, Carlton, J, Frahm, K, Gorringe, T, Kammel, P, Swanson, E, Hertzog, D W, LaBounty, J, Roehnelt, R, Schwendimann, P, Taylor, B

2025

Overview

We report measurements of ten custom-made high-homogeneity LYSO crystals. The investigation is motivated by the need for a compact, high-resolution, and fast electromagnetic calorimeter for a new rare pion decay experiment. Each \\(2.5\\times 2.5 \\times 18\\) cm\\(^3\\) crystal was first characterized for general light yield properties and then its longitudinal response uniformity and energy resolution were measured using low-energy gamma sources. The ten crystals were assembled as an array and subjected to a 30 - 100 MeV positron beam with excellent momentum definition. The energy and timing resolutions were measured as a function of energy, and the spatial resolution was determined at 70 MeV. An additional measurement using monoenergetic 17.6 MeV gammas produced through a p-Li resonance was later made after the photosensors used in positron testing were improved. As an example of the results, the energy resolution at 70 MeV of 1.52 \\(\\pm\\) 0.03% is more than two times better than reported results using previous generation LYSO crystals.

• Publisher: Cornell University Library, arXiv.org
• Subject: Arrays / Crystals / Energy resolution / Homogeneity / Pions / Positron beams / Spatial resolution