Measurement of the normalized ${}^{238}$U(n,f)/${}^{235}$U(n,f) cross section ratio from threshold to 30 MeV with the fission Time Projection Chamber

Abstract

The normalized ${}^{238}$U(n,f)/${}^{235}$U(n,f) cross section ratio has been measured using the NIFFTE fission Time Projection Chamber from the reaction threshold to $30$~MeV. The fissionTPC is a two-volume MICROMEGAS time projection chamber that allows for full three-dimensional reconstruction of fission-fragment ionization profiles from neutron-induced fission. The measurement was performed at the Los Alamos Neutron Science Center, where the neutron energy is determined from neutron time-of-flight. The ${}^{238}$U(n,f)/${}^{235}$U(n,f) ratio reported here is the first cross section measurement made with the fissionTPC, and will provide new experimental data for evaluation of the ${}^{238}$U(n,f) cross section, an important standard used in neutron-flux measurements. Use of a development target in this work prevented the determination of an absolute normalization, to be addressed in future measurements. Instead, the measured cross section ratio has been normalized to ENDF/B-VIII.$\beta$5 at 14.5 MeV.

References in corpus (1)

• A Time Projection Chamber for High Accuracy and Precision Fission Cross Section Measurements

Cited by in corpus (4)

• Fission Fragment Angular Anisotropy in Neutron-Induced Fission of ${}^{235}$U Measured with a Time Projection Chamber
• EXFOR-based simultaneous evaluation of neutron-induced uranium and plutonium fission cross sections for JENDL-5
• Neutron Induced Fission Fragment Angular Distributions, Anisotropy, and Linear Momentum Transfer Measured with the NIFFTE Fission Time Projection Chamber
• 1H(n,el) as a Cross Section Reference in a White Source Neutron Beam With the fissionTPC