Speaker
Description
In 2017, the COHERENT collaboration reported the first measurement of CEvNS using a sodium-doped cesium-iodide detector, CsI[Na], with subsequent analysis improvements and additional data that led to more precise results. The COHERENT collaboration is currently developing a cryogenic undoped CsI detector with expected lower energy thresholds, increased light yield at temperatures ranging from 40 K to 80 K, and background reduction techniques to greatly improve the sensitivity to CEvNS measurements. The CryoCsI team has constructed and tested a cryostat for 77 K operation with a 10 kg pure CsI crystal, optimized coupling to silicon photomultipliers (SiPMs) for scintillation detection, and designed shielding with muon veto panels for minimizing backgrounds. The parts of the apparatus are being prepared for shipping to the Oak Ridge National Laboratory (ORNL) in Tennessee, USA, where the complete system will be assembled, tested, and deployed to the Spallation Neutron Source (SNS). Initial data acquisition will focus on detector characterization and background studies. While initial estimates are a 2 sigma sensitivity to non-standard interactions with 3 years of data, better predictions will be determined after the commissioning data runs. In addition, members of the COHERENT team have measured the light yield of pure CsI at 77 K in preparation for analyzing the CryoCsI data.