자료유형  

 학위논문

Control Number  

0017160466

International Standard Book Number  

9798384451709

Dewey Decimal Classification Number  

539.76

Main Entry-Personal Name  

Nagel, Tyler Scott.

Publication, Distribution, etc. (Imprint  

[S.l.] : University of California, Berkeley., 2024

Publication, Distribution, etc. (Imprint  

Ann Arbor : ProQuest Dissertations & Theses, 2024

Physical Description  

94 p.

General Note  

Source: Dissertations Abstracts International, Volume: 86-03, Section: B.

General Note  

Advisor: Bernstein, Lee.

Dissertation Note  

Thesis (Ph.D.)--University of California, Berkeley, 2024.

Summary, Etc.  

요약Neutron induced reactions on Chlorine, especially 35Cl, have wide relevance across the nuclear science spectrum. The 35Cl(n, p0) 35S channel is particularly vital to the design of Molten Chloride Fast Reactors (MCFR) as it impacts core reactivity through neutron loss in the Chlorine based carrier salt. However, until 2019, very little experimental data existed for the relevant energy range. Secondary γ-ray production data for the 35Cl(n, p) 35S reaction are also needed for national security applications, including active neutron interrogation, yet there is currently no useful experimental data available. Gamma-ray data is also used in space exploration for detecting the isotopic makeup of extraterrestrial environments as well as in oil-well logging. To address these nuclear data needs, measurements of the 35Cl(n,x) reaction cross sections were conducted at Lawrence Berkeley National Laboratory's (LBNL) 88-inch cyclotron.The nuclear data evaluation process that produces the cross sections used for applications assumes a fixed total (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 a multi-component experiment whose goal was to measure all energetically possible reaction channels instead of using the more common single channel approach. The experiment consisted of three independent parts. First, the energy differential 35Cl(n, p0) 35S cross section was obtained using a CLYC detector as an active target. Second, energy-differential γ-ray production data for 35Cl(n, pγ) 35S and 35Cl(n, n'γ) 35Cl were obtained using the GENESIS array. This data was compared against (elsewhere produced) CoH3 theoretical calculations to inform model predictions as to the relative strength of available reaction channels. Finally, energy-integral 35Cl(n,p) and 35Cl(n,α) cross sections from activation were compared against CoH3. These allow verification of the inelastic channel strength obtained from the γ-ray data as well as determining the total 35Cl(n,α) channel strength which was not available from the other methods.Our results identify a ∼50% reduction in the magnitude of the 35Cl(n, p0) 35S cross section compared to the ENDF/B-VIII.0 evaluation. This result is consistent with a 2020 measurement by Kuvin et. al. Comparison of the γ-ray production data to CoH3 model calculations suggest that the elastic and/or inelastic channels must increase to compensate for the reduction observed in the (n, p0) channel.

Subject Added Entry-Topical Term  

Nuclear engineering.

Subject Added Entry-Topical Term  

Nuclear physics.

Subject Added Entry-Topical Term  

Energy.

Subject Added Entry-Topical Term  

Inorganic chemistry.

Subject Added Entry-Topical Term  

Nuclear chemistry.

Subject Added Entry-Topical Term  

Computational physics.

Index Term-Uncontrolled  

Molten Chloride Fast Reactors

Index Term-Uncontrolled  

Gamma-ray data

Index Term-Uncontrolled  

Neutron induced reactions

Index Term-Uncontrolled  

Chlorine

Index Term-Uncontrolled  

Inelastic channels

Added Entry-Corporate Name  

University of California, Berkeley Nuclear Engineering

Host Item Entry  

Dissertations Abstracts International. 86-03B.

Electronic Location and Access  

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Control Number  

joongbu:657360