High-pressure Xenon Gas Electroluminescent TPC Concept for Simultaneous Searches for Decay and WIMP Dark Matter
Xenon is increasingly popular for both direct WIMP and 0 decay searches. Although the current trend has exploited the liquid phase, gas phase xenon offers some remarkable performance advantages for energy resolution, topology visualization, and discrimination between electron and nuclear recoils. The NEXT-100 experiment, now beginning construction in the Canfranc Underground Laboratory, Spain, will operate at 15 bars with 100 kg of 136Xe for the 0 decay search. I will describe recent results with small prototypes, indicating that NEXT-100 can provide about 0.5% FWHM energy resolution at the decay Q-value, as well as topological rejection of rays.
However, sensitivity goals for both WIMP dark matter and 0 decay searches indicate the need for ton-scale active masses; NEXT-100 provides the springboard to this scale. I present a scenario for conducting both searches in a single high-pressure ton-scale xenon gas detector, without significant compromise to either. In addition, an automatic sensitivity to WIMP directionality – even in a single, ton-scale, high-pressure xenon gas TPC – may exist, plausibly offering an advance of three orders of magnitude relative to current low-pressure TPC concepts. I argue that, in an era of deepening fiscal austerity, such a dual-purpose detector may be possible, at acceptable cost, within the time frame of interest, and deserves our collective attention.