Instrumentation for correlated prompt n−γ emission studies in coincidence with fission fragments

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Vol. 1048; p. 168027
• Main Authors: Marin, S., Tolstukhin, I.A., Giha, N.P., Oberling, M.B., Knaack, R.A., Kay, B.P., Duke, D.L., Montoya, K.B., Connolly, D., Loveland, W., Chemey, A., Pozzi, S.A., Tovesson, F.
• Format: Journal Article
• Language: English
• Published: United States Elsevier B.V 01.03.2023; Elsevier
• Subjects: INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; Ionization chamber; Nuclear fission; Particle correlation instrumentation; Particle correlation instrumentation; Ionization chamber; Nuclear fission
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/j.nima.2023.168027

Recent theoretical and experimental results have brought renewed interest and focus on the topic of fission fragment angular momentum. Measurements of neutrons and γ rays in coincidence with fission fragments remain the most valuable tool in the exploration of fission physics. To achieve these scientific goals, we have developed a system that combines a state-of-the-art fission fragment detector and n−γ radiation detectors. A new twin Frisch-gridded ionization chamber has been designed and constructed for use with a spontaneous fission source and an array of forty trans-stilbene organic scintillators (FS-3) at Argonne National Laboratory. The new ionization chamber design we present in this work aims at minimizing particle attenuation in the chamber walls, and provides a compact apparatus that can be fit inside existing experimental systems. The ionization chamber is capable of measuring fission fragment masses and kinetic energies, whereas the FS-3 provides neutron and γ-ray multiplicities and spectra. The details of both detector assemblies are presented along with the first experimental results of this setup. Planned event-by-event analysis and future experiments are briefly discussed.