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Title: Suppression of the internal Conversion Decay of Th-229m (FY19Q1 report)

Abstract

To measure the decay energy of metastable Th-229m, we had proposed to modify an existing experiment by placing a MgF 2 crystal between our U-233 source and a high-resolution STJ photon detector. Metastable Th-229m nuclei produced in the decay of U-233 would be absorbed in the MgF 2, but since the MgF 2 bandgap of ~10eV exceeds the energy of the metastable state, decay by internal conversion is expected to be suppressed. Th-229m can then only decay by gamma emission, and the ~7.8 eV gamma energy can be transmitted through the MgF 2 and detected by the STJ detector. The spectra are calibrated with a pulsed 355 nm laser.

Authors:
 [1]
  1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1491980
Report Number(s):
LLNL-TR-765340
955347
DOE Contract Number:  
AC52-07NA27344
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING; 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 73 NUCLEAR PHYSICS AND RADIATION PHYSICS

Citation Formats

Friedrich, Stephan. Suppression of the internal Conversion Decay of Th-229m (FY19Q1 report). United States: N. p., 2019. Web. doi:10.2172/1491980.
Friedrich, Stephan. Suppression of the internal Conversion Decay of Th-229m (FY19Q1 report). United States. doi:10.2172/1491980.
Friedrich, Stephan. Tue . "Suppression of the internal Conversion Decay of Th-229m (FY19Q1 report)". United States. doi:10.2172/1491980. https://www.osti.gov/servlets/purl/1491980.
@article{osti_1491980,
title = {Suppression of the internal Conversion Decay of Th-229m (FY19Q1 report)},
author = {Friedrich, Stephan},
abstractNote = {To measure the decay energy of metastable Th-229m, we had proposed to modify an existing experiment by placing a MgF2 crystal between our U-233 source and a high-resolution STJ photon detector. Metastable Th-229m nuclei produced in the decay of U-233 would be absorbed in the MgF2, but since the MgF2 bandgap of ~10eV exceeds the energy of the metastable state, decay by internal conversion is expected to be suppressed. Th-229m can then only decay by gamma emission, and the ~7.8 eV gamma energy can be transmitted through the MgF2 and detected by the STJ detector. The spectra are calibrated with a pulsed 355 nm laser.},
doi = {10.2172/1491980},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2019},
month = {1}
}