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Title: MagMicro with Ultra-High Energy Resolution (Progress Report Q4 FY18)

Technical Report ·
DOI:https://doi.org/10.2172/1529184· OSTI ID:1529184
 [1]
  1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

We are performing extensive simulations of the MMC detector response to optimize their energy resolution, detection efficiency and count rate based on the data we took in FY17/18. The optimized layout separates the MMC detector chip from the SQUID preamplifier chips coupled to the MMCs through Al wire bonds to avoid heating the MMC with the power dissipation of the SQUID. The goal is to design MMC gamma detectors with a limiting energy resolution below ~25 eV FWHM up to >100 keV and ~1 ms decay times for maximum count rates of several tens of counts/s per pixel. The simulations, which were done at the Supercomputing Center of the University of New Mexico, are taking significantly longer than expected. The difficulty is that the device performance depends intricately on the design parameters, and each simulation is quite involved because it needs to cover the frequency range well into the GHz range to account for the ac Josephson effect. This is delaying the start of the detector array fabrication, and we have not been able to complete the fabrication and the testing of the 32-pixel MMC arrays by September 30. We have therefore requested a no-cost extension of the project to March 31, 2019.

Research Organization:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA)
DOE Contract Number:
AC52-07NA27344
OSTI ID:
1529184
Report Number(s):
LLNL-TR-779043; 964765
Country of Publication:
United States
Language:
English