Aluminum STJ Development Towards Phase-IV of the BeEST Experiment

ORAL

Abstract

The Beryllium Electron capture in Superconducting Tunnel junction (BeEST) experiment is a search for sub-MeV neutrino mass states in the electron capture decay of 7Be. Phase-IV of the experiment requires the use of new Al-based STJ arrays to improve our sensitivity by more than two orders of magnitude. The Phase-IV STJ sensors are purpose designed and fabricated for the BeEST experiment and include several key features that allow for higher precision measurements of the decay spectrum. In this talk, I will present the basic design changes and the motivation for using Al-based sensors, as well as show data collected from our prototype aluminum devices with a comparison to data from our previous tantalum-based arrays.

LLNL-PRES-843745

*The BeEST experiment is supported, in part, by the DOE-SC Office of Nuclear Physics, the Gordon and Betty Moore Foundation, and the European Metrology Programme for Innovation and Research (EMPIR). TRIUMF receives federal funding via a contribution agreement with the National Research Council of Canada. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52- 07NA27344. This research was performed under appointment to the Nuclear Nonproliferation International Safeguards Fellowship Program sponsored by the NationalNuclear Security Administration's Office of International Nuclear Safeguards (NA-241).

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Presenters

  • Spencer Fretwell

    • Colorado School of Mines

Authors

  • Spencer Fretwell

    • Colorado School of Mines