Dark matter with HELLAZ
Résumé
Dark matter interacting in a pressurized TPC will produce an energy spectrum of recoil nuclei whose end point depends on the atomic mass and the pressure of the gas. These can be varied from He to Xe, and 10$^{-2}$ to 20 bar. The threshold depends on the gain of the end cap detector and can reach single electron capability, that is a few eV. HELLAZ has reached that gain with 20 bar He. Parts of this presentation are taken from [J.I. Collar, Y. Giomataris, Nucl. Inst. Meth. 471 (2001) 254].