First Demonstration of the HeRALD Superfluid Helium Detector Concept
Abstract
The SPICE/HeRALD collaboration is performing R&D to enable studies of sub-GeV dark matter models using a variety of target materials. Here we report our recent progress on instrumenting a superfluid He target mass with a transition-edge sensor based calorimeter to detect both atomic signals (scintillation) and He quasiparticle (phonon and roton) excitations. The sensitivity of HeRALD to the critical "quantum evaporation" signal from He quasiparticles requires us to block the superfluid film flow to the calorimeter. We have developed a heat-free film-blocking method employing an unoxidized Cs film, which we implemented in a prototype "HeRALD v0.1" detector of ~10 g target mass. This article reports initial studies of the atomic and quasiparticle signal channels. A key result of this work is the measurement of the quantum evaporation channel's gain of 0.15 0.01, which will enable He-based dark matter experiments in the near term. With this gain the HeRALD detector reported here has an energy threshold of 145 eV at 5 sigma, which would be sensitive to dark matter masses down to 220 MeV/c.
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Cite
@article{arxiv.2307.11877,
title = {First Demonstration of the HeRALD Superfluid Helium Detector Concept},
author = {R. Anthony-Petersen and A. Biekert and C. L. Chang and Y. Chang and L. Chaplinsky and A. Dushkin and C. W. Fink and M. Garcia-Sciveres and W. Guo and S. A. Hertel and X. Li and J. Lin and R. Mahapatra and W. Matava and D. N. McKinsey and D. Z. Osterman and P. K. Patel and B. Penning and H. D. Pinckney and M. Platt and M. Pyle and Y. Qi and M. Reed and G. R. C Rischbieter and R. K. Romani and A. Serafin and B. Serfass and R. J. Smith and P. Sorensen and B. Suerfu and A. Suzuki and V. Velan and G. Wang and Y. Wang and S. L. Watkins and M. R. Williams},
journal= {arXiv preprint arXiv:2307.11877},
year = {2024}
}
Comments
14 pages, 9 figures