Low energy conversion electron detection in superfluid $^{3}He$ at ultra-low temperature

Emmanuel Moulin (1) , C. Winkelmann , J.F. Macias-Perez (1) , Yu. M. Bunkov , H. Godfrin , D. Santos (1)

1 LPSC - Laboratoire de Physique Subatomique et de Cosmologie

We report on the first results of the MACHe3 (MAtrix of Cells of Helium 3) prototype experiment concerning the measurement of low energy conversion electrons at ultra-low temperature. For the first time, the feasibility of the detection of low energy electrons is demonstrated in superfluid He3-B cooled down to 100 microK. Low energy electrons at 7.3 keV coming from the K shell conversion of the 14.4 keV nuclear transition of a low activity Co57 source are detected, opening the possibility to use a He3-based detector for the detection of Weakly Interacting Massive Particles (WIMPs) which are expected to release an amount of energy higher-bounded by 5.6 keV.

Mots clés: dark matter; ultra-low temperature; helium 3; bolometer

Domaines: Cosmologie et astrophysique extra-galactique [astro-ph.CO]; Astrophysique [astro-ph]

Emmanuel Moulin, C. Winkelmann, J.F. Macias-Perez, Yu. M. Bunkov, H. Godfrin, et al.. Low energy conversion electron detection in superfluid $^{3}He$ at ultra-low temperature. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2005, 548, pp.411-417. ⟨10.1016/j.nima.2005.04.060⟩. ⟨in2p3-00024072⟩