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Measurements of $^{35}$Cl(n,x) reaction cross sections were conducted at Lawrence Berkeley National Laboratory’s (LBNL) 88-Inch Cyclotron using neutrons produced via thick target deuteron breakup from a 14 MeV deuteron beam. These cross sections are vital to the design of Molten Chloride Fast Reactors (MCFR), especially in the 0.1 MeV – 1.0 MeV region where little experimental data exist but almost half of the MCFR neutron spectrum lies. The nuclear data evaluation process that produces the cross sections used for the design of an MCFR assumes a fixed total $^{35}$Cl(n,x) cross section. The result is that an increase in one channel causes a corresponding decrease in one or more other evaluated channel(s). To address this aspect of nuclear data evaluation, we performed an experiment with the goal of measuring all energetically possible reaction channels. The experiment consisted of three independent parts. First, energy-angle differential (n,n’${\gamma}$) cross sections were obtained using the GENESIS array, a collection of high-purity germanium detectors and LaBr inorganic scintillators for ${\gamma}$-ray detection as well as EJ-309 organic scintillators for neutron detection. Second, (n,p) and (n,${\alpha}$) energy differential cross sections were obtained using a CLYC elpasolite scintillator as an active target. Finally, energy integral (n,p) and (n,${\alpha}$) cross sections were obtained from the production of the $^{35}$S and $^{32}$P activation products in a pressed NaCl tablet. The results were compared to reaction modeling using the TALYS reaction code package.
This work was performed under the auspices of the U.S. Department of Energy (DOE) by Lawrence Berkeley National Laboratory under Contract DE-AC02-05CH11231, the DOE Nuclear Energy University Program (NEUP), and Lawrence Livermore National Laboratory under Contract DE-AC52- 07NA27344.
