Ultra-Fast, Radiation Hard Scintillators for High Energy Physics

Statement of Problem Scintillators with very fast decay (< 10 ns) are needed to handle the very high event rate in future high energy physics (HEP) experiments. They are also expected to be extremely radiation hard without the necessity of replacement, to withstand integrated high absorbed doses of the order of hundred Mrads. The progress in the detection technology can be maintained and leveraged only if new materials are developed. How the Problem is Addressed In this project we plan to develop a novel ultra-fast, radiation-hard scintillator for new generation of calorimeters. To meet these requirements, we propose to investigate a set of promising new materials that rely on traditionally fast scintillation mechanisms such as Donor-Acceptor Pair (DAP) luminescence, Core-to-Valence Luminescence (CVL), and Charge Transfer (CT) luminescence, and ultimately develop one of them for HEP Instrumentation. These materials include compositions based on: (1) TlCl; (2) Cs2ZnCl4; and (3) Lu2O3, respectively. Work done in Phase I In Phase I of the research, we studied three different scintillator materials. Crystals and ceramics were manufactured, and scintillation properties and radiation hardness were studied. Based on the overall properties we have down selected one of the materials (Lu2-xYxO3:Yb) for further development in Phase II. Plans for Phase II During Phase II we will optimize the manufacturing process to fabricate transparent, high-quality samples of Lu2-xYxO3:Yb. We will perform radiation hardness measurements up to 1 MRad by irradiating with both gamma-rays and hadrons. We will develop manufacturing process to achieve sample sizes used in EM calorimeters 20 cm long bars with a cross-section of 2×2 cm2 that can compete with PbWO4 crystals in calorimetry and other experiments. Commercial and Scientific Potential In addition to high energy physics applications, ultra-fast and radiation hard materials would be attractive for high count rate applications such as nuclear fuel monitoring, dosimetry, detectors for measuring radiation in the event of a nuclear blast, energy resolved high energy radiography, or medical applications such as Positron-Emission-Tomography. The proposed material can deliver performance that surpasses the benchmark materials at potentially lower cost.