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Title: ZEUS Activation Foils Report for Experiments 1-5

Technical Report ·
DOI:https://doi.org/10.2172/1493007· OSTI ID:1493007
 [1];  [1];  [1]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

The ZEUS experiments were conducted using the COMET vertical assembly machine at the Los Alamos Critical Experiments Facility (LACEF) at the Los Alamos National Laboratory (LANL). The experiments were designed to check the adequacy of cross sections in the intermediate-energy range. For the first four experiments, 12 kg highly enriched uranium (HEU) layers were sandwiched between different numbers of graphite plates in a vertical stack. In the first four experiments, a unit cell consisted of n graphite plates, an HEU layer, and then another n graphite plates. The unit cells were stacked until criticality was obtained. Experiments 1, 2, 3, and 4 contained decreasing amounts of graphite, where the unit cells value n was 4, 3, 2 and 1 respectively. In experiment 5 the HEU plates were in direct contact with each other to evaluate cross sections in the fast-energy range. A detailed description of experiments 1-4 is provided in reference, and of experiment 5, in reference. In order to investigate the cross sections in more detail, some ZEUS runs were made with activation foils inside the assemblies. Ratios of the activations of various foils are a standard method of measuring the gross neutron spectrum shape. A more detailed spectrum can be determined by simultaneously unfolding the response of several foils. This report describes the unfolding of the ZEUS activation foils data. The focus in this analysis is on the fast-energy range, especially at > 5 MeV.

Research Organization:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
Sponsoring Organization:
USDOE
DOE Contract Number:
89233218CNA000001
OSTI ID:
1493007
Report Number(s):
LA-UR-19-20453
Country of Publication:
United States
Language:
English