Holman, G. | Engineering Papers

DOE OSTI2020

Beta Decay of Molecular Tritium

The beta decay of tritium in the form of molecular T 2 is the basis of sensitive experiments to measure neutrino mass. The final-state electronic, vibrational, and rotational excitations modify the beta spectrum significantly and are obtained from theory. We further determine measurements of the branching ratios to specific ionization states for the isotopolog HT. Two earlier, concordant measurements gave branching ratios of HT to the bound HHe + ion of 89.5% and 93.2%, in sharp disagreement with the theoretical prediction of 55%–57%, raising concerns about the theory’s reliability in neutrino mass experiments. Our finding, 56.5(6)%, is compatible with the theoretical expectation and disagrees strongly with the previous measurements.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

DOE OSTI2014

Performance Analysis: Issues Tracking System Data through June 2013

This report presents the results from an analysis of issues and assessments in LLNL’s Issues Tracking System (ITS). The analysis is conducted to identify issues that may require additional management attention and noncompliances that may not have been previously identified that meet the threshold for reporting to the DOE Noncompliance Tracking System (NTS) or to the DOE Safeguards and Security Information Management System (SSIMS). This report includes ITS data within the DOE Office of Enforcement regulated subjects through June 2013. The analysis in this report primarily focuses on deficiencies identified in the last twelve months. The analysis of issues concluded that data for 17 of the 25 Office of Enforcement regulated safety/security subjects were within expected variation. The data for eight met a common test and were discussed further. Three of the eight safety subjects met an action limit and were analyzed to resolution. Analysis of data from one of the safety subjects where a common test was met identified a potential safety related significant or programmatic (systemic) noncompliance with the LLNL work planning and control process. Additional analysis is needed to make a final determination. Note: Since the analysis of WPC deficiencies (through June 2013) was completed, a noncompliance evaluation was also completed in November 2013 and included more recent WPC deficiencies. The analysis of ITS data through June 2013, and the results of the noncompliance evaluation completed in November 2013 led to LLNL filing a programmatic noncompliance report to the NTS in January 2014 titled, Programmatic noncompliance with topical areas within LLNL’s Work Planning and Control process.

99 GENERAL AND MISCELLANEOUS↗

NASA NTRS1979

N-body experiments and missing mass in clusters of galaxies

It is commonly assumed that the distributions of surface density and radial-velocity dispersion in clusters of galaxies are sensitive tracers of the underlying distribution of any unseen mass. N-body experiments have been used to test this assumption. Calculations with equal-mass systems indicate that the effects of the underlying mass distribution cannot be detected by observations of the surface-density or radial-velocity distributions, and the existence of an extended binding mass in all well-studied clusters would be consistent with available observations.

Smith, H.↗