The Low-Mass Limit – Dark Matter Detectors with eV-Scale Energy Resolution

  • July 20, 2018, 4:00 pm
  • Wilson Hall, 1 West (WH1W)
  • Noah Kurinsky, Stanford

The SuperCDMS experiment has designed a new generation of dark matter detectors which have recently demonstrated sensitivity to events with a single charge, equivalent to a minimum event energy of 1.2 eV, the indirect bandgap energy of Si, with very low dark counts. This level of sensitivity was achieved partially through the use of Luke-Neganov gain, in which charges are accelerated through a high electric field to generate phonons, which amplify the initial charge signal. This pre-amplification, while crucial, required a gram-scale phonon detector with energy resolution on the order of 10 eV, a technical challenge in its own right. The design of this and similar phonon sensors based on a topology of a superconducting phonon sink and a low-Tc Tungsten TES on scales from mg to kg has been the focus on my thesis work.

In this talk I will discuss the motivation for developing such low-Tc devices, as well as the experimental and logistical challenges associated with successful operation of low-Tc TES sensors in light of our recent results. I will also discuss some of the new backgrounds which arise as a result of lower energy and power sensitivity, and ways in which such backgrounds might be mitigated. I will conclude by discussing prospects for upcoming dark matter searches utilizing this technology for the upcoming SuperCDMS SNOLAB experiment.