The coherent elastic scattering of neutrinos on nuclei, also known as CEvNS, has been studied for several years by the COHERENT program of experiments using neutrinos from stopped-pion decays produced at the Spallation Neutron Source (SNS). We propose a new approach for CEvNS measurements at the SNS that aims to complement the COHERENT experiments in two main ways: by reconstructing the angular distribution of CEvNS-induced recoils, and by measuring CEvNS on much lighter target nuclei such as helium, carbon, and fluorine. The proposed detector would employ a gaseous time-projection chamber with a highly segmented charge readout to enable the spatial reconstruction of $\sim$10-500 keV ionisation tracks created by CEvNS-induced recoils. This would enable the simultaneous measurement of the CEvNS recoil energy and scattering angle, thereby allowing event-by-event reconstruction of the neutrino energy. We estimate that a 60:40 He:CF$_4$ gas mixture at atmospheric pressure offers a good trade-off between total target mass and good directionality and could deliver a detection of the angular distribution of CEvNS, even under pessimistic background conditions. We project the sensitivity of 1 and 10 m$^3$-scale detectors in the context of several physics cases, including: the measurement of the Standard Model CEvNS cross section, reconstruction of the flavour-dependent neutrino fluxes, observing the neutrino-induced Migdal effect, constraints on beyond-Standard Model neutrino interactions, and probing 10-eV-scale sterile neutrinos.
University of South Dakota（南达科他大学）；Seoul National University（首尔大学）；Florida State University（佛罗里达州立大学）；Duke University（杜克大学）；Triangle Universities Nuclear Laboratory（三角大学核实验室）；National Research Nuclear University MEPhI (Moscow Engineering Physics Institute)（莫斯科工程物理国家研究大学）；National Research Center “Kurchatov Institute”（库尔恰托夫国家研究中心）；University of Tennessee, Knoxville（田纳西大学诺克斯维尔分校）；North Carolina State University（北卡罗来纳州立大学）；Sandia National Laboratories（桑迪亚国家实验室）；University of Chinese Academy of Sciences（中国科学院大学）
Neutral-current neutrino-nucleus scattering off I (127) and Cs (133): Coherent and incoherent contributions with electroweak refinements for odd-A nuclei
Air University（伊斯兰堡空军大学）；University of Caen Normandy（诺曼底卡昂大学）
