CAREER: Development of a New Generation of Gas-based Detectors for the Directionality Signature from Dark Matter

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In this era of precision cosmology, measurements suggest that ordinary matter (protons and neutrons) makes up a mere 15% of the total matter density in the Universe. The rest, whose effect we can only see gravitationally, appears to be dark. The goal of detecting and identifying dark matter is widely recognized as one of the most important problems in 21st century cosmology. Current particle physics models suggest that dark matter might be weakly interacting massive particles (WIMPs) left over from the Big Bang. Efforts to directly detect WIMPs are hampered by small interaction probabilities and large backgrounds which mimic expected dark matter signals. Fortunately, a number of unique dark matter signatures exist which, if exploited, can be used to discriminate against backgrounds. These are based on the predicted behavior of the WIMP flux as the Sun-Earth system moves through the galaxy. The largest and most robust of these signatures is a day-night modulation of nuclear recoil directions in the lab frame. Of current experimental searches for dark matter only one, Directional Recoil Identification From Tracks (DRIFT), is equipped to detect this directionality signature. The main subject of this proposal is to experimentally study novel detectors for future directionally sensitive dark matter detectors. These studies will focus on improving DRIFT's sensitivity for measuring directionality by taking full advantage of the directional signature from halo WIMPs while maintaining DRIFT's good background rejection capabilities, intrinsic low-maintainability, and low cost per unit mass. The goals of this research are to quantify the advantages and disadvantages of the new technologies by measuring their performance in the laboratory, and to assess the feasibility of employing these new technologies in future, large mass directional dark matter experiments.Broader impacts of this work include the training of undergraduate and graduate students (including underrepresented minorities). Additionally, a targeted Outreach Program for the professional development of middle- and high-school teachers will be developed. As part of this program, each year a 1-day workshop will be offered, followed by a 2-week intensive course, with graduate credit towards a M.A. in Education, for teachers across New Mexico. This will take place in collaboration with and support from the Lodestar Astronomy Center and the Science Education Institute of the Southwest.