Ionization yield measurement in a germanium CDMSlite detector using photo-neutron sources
Abstract
Two photo-neutron sources, YBe and SbBe, have been used to investigate the ionization yield of nuclear recoils in the CDMSlite germanium detectors by the SuperCDMS collaboration. This work evaluates the yield for nuclear recoil energies between 1 keV and 7 keV at a temperature of 50 mK. We use a Geant4 simulation to model the neutron spectrum assuming a charge yield model that is a generalization of the standard Lindhard model and consists of two energy dependent parameters. We perform a likelihood analysis using the simulated neutron spectrum, modeled background, and experimental data to obtain the best fit values of the yield model. The ionization yield between recoil energies of 1 keV and 7 keV is shown to be significantly lower than predicted by the standard Lindhard model for germanium. There is a general lack of agreement among different experiments using a variety of techniques studying the low-energy range of the nuclear recoil yield, which is most critical for interpretation of direct dark matter searches. This suggests complexity in the physical process that many direct detection experiments use to model their primary signal detection mechanism and highlights the need for further studies to clarify underlying systematic effects that have not been well understood up to this point.
Keywords
Cite
@article{arxiv.2202.07043,
title = {Ionization yield measurement in a germanium CDMSlite detector using photo-neutron sources},
author = {SuperCDMS Collaboration and M. F. Albakry and I. Alkhatib and D. W. P. Amaral and T. Aralis and T. Aramaki and I. J. Arnquist and I. Ataee Langroudy and E. Azadbakht and S. Banik and C. Bathurst and D. A. Bauer and L. V. S. Bezerra and R. Bhattacharyya and M. A. Bowles and P. L. Brink and R. Bunker and B. Cabrera and R. Calkins and R. A. Cameron and C. Cartaro and D. G. Cerdeño and Y. -Y. Chang and M. Chaudhuri and R. Chen and N. Chott and J. Cooley and H. Coombes and J. Corbett and P. Cushman and F. De Brienne and M. L. di Vacri and M. D. Diamond and E. Fascione and E. Figueroa-Feliciano and C. W. Fink and K. Fouts and M. Fritts and G. Gerbier and R. Germond and M. Ghaith and S. R. Golwala and J. Hall and B. A. Hines and M. I. Hollister and Z. Hong and E. W. Hoppe and L. Hsu and M. E. Huber and V. Iyer and A. Jastram and V. K. S. Kashyap and M. H. Kelsey and A. Kubik and N. A. Kurinsky and R. E. Lawrence and M. Lee and A. Li and J. Liu and Y. Liu and B. Loer and P. Lukens and D. MacDonell and D. B. MacFarlane and R. Mahapatra and V. Mandic and N. Mast and A. J. Mayer and H. Meyer zu Theenhausen and É. Michaud and E. Michielin and N. Mirabolfathi and B. Mohanty and J. D. Morales Mendoza and S. Nagorny and J. Nelson and H. Neog and V. Novati and J. L. Orrell and M. D. Osborne and S. M. Oser and W. A. Page and R. Partridge and D. S. Pedreros and R. Podviianiuk and F. Ponce and S. Poudel and A. Pradeep and M. Pyle and W. Rau and E. Reid and R. Ren and T. Reynolds and A. Roberts and A. E. Robinson and T. Saab and B. Sadoulet and I. Saikia and J. Sander and A. Sattari and A. Scarff and B. Schmidt and R. W. Schnee and S. Scorza and B. Serfass and D. J. Sincavage and C. Stanford and J. Street and F. K. Thasrawala and D. Toback and R. Underwood and S. Verma and A. N. Villano and B. von Krosigk and S. L. Watkins and O. Wen and Z. Williams and M. J. Wilson and J. Winchell and K. Wykoff and S. Yellin and B. A. Young and T. C. Yu and B. Zatschler and S. Zatschler and A. Zaytsev and E. Zhang and L. Zheng and S. Zuber},
journal= {arXiv preprint arXiv:2202.07043},
year = {2022}
}