Low pressure gaseous Time Projection Chambers (TPCs) are a viable technology for directional Dark Matter (DM) searches and have the potential for exploring the parameter space below the neutrino fog. Gases like CF4 are advantageous because they contain flourine which is predicted to have heightened elastic scattering rates with a possible Weakly Interacting Massive Particle (WIMP) DM candidate. The low pressure of CF4 must be maintained, ideally lower than 100 Torr, in order to elongate potential Nuclear Recoil (NR) tracks which allows for improved directional sensitivity and NR/Electron Recoil (ER) discrimination. Recent evidence suggests that He can be added to heavier gases, like CF4, without significantly affecting the length of 12C and 19F recoils due to its lower mass. Such addition of He has the advantage of improving sensitivity to lower mass WIMPs. Simulations can not reliably predict operational stability in these low pressure gas mixtures and thus must be demonstrated experimentally. In this paper we investigate how the addition of He to low pressure CF4 affects the gas gain and energy resolution achieved with a single Thick Gaseous Electron Multiplier (ThGEM).
He-CF4-CH4 ternary mixtures as target gas for the CYGNO directional dark matter experiment
University of Coimbra（科英布拉大学）；Universit`a Roma TRE（罗马三所大学）；Istituto Nazionale di Fisica Nucleare（意大利国家核物理研究所；罗马三分所）；Sezione di Roma Tre（格兰萨索科学研究所）；Gran Sasso Science Institute（意大利国家核物理研究所；格兰萨索国家实验室）；Istituto Nazionale di Fisica Nucleare（意大利国家核物理研究所；弗拉斯卡蒂国家实验室）；Laboratori Nazionali del Gran Sasso（意大利国家新科技、能源和可持续经济发展局弗拉斯卡蒂研究中心）；Istituto Nazionale di Fisica Nucleare（茹伊斯迪福拉联邦大学）；Laboratori Nazionali di Frascati（罗马大学）；ENEA Centro Ricerche Frascati（意大利国家核物理研究所；罗马分所）；Universidade Federal de Juiz de Fora（罗马大学）；Universit`a di Roma Sapienza（谢菲尔德大学）；Istituto Nazionale di Fisica Nucleare；Sezione di Roma；Sapienza Universit`a di Roma；University of Sheffield
