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Title: Neutron decay from the isobaric analog state in {sup 120}Sb populated in {sup 120}Sn({sup 3}He,{ital t}){sup 120}Sb at {ital E}({sup 3}He) = 200 MeV, {theta} = 0{degree}

Abstract

The {sup 120}Sn({sup 3}He,{ital t}){sup 120}Sb charge-exchange reaction has been investigated at {ital E}({sup 3}He) = 200 MeV and {theta}{approx}0{degree} to study neutron decay from the isobaric analog state at {ital E}{sub {ital x}}=10.20 MeV in {sup 120}Sb. The low-energy neutrons (average energy {similar_to}0.85 MeV) were detected in coincidence with tritons observed in the focal plane of a high-resolution magnet spectrometer. Four small deuterated NE230 scintillation detectors were mounted at distances of 9.5 cm from the target resulting in an overall neutron detection efficiency including solid angle of {gt}1%. This efficiency was obtained by combining the measured dependence on neutron energy with a calculated neutron evaporation spectrum. From the measured ratio of coincidence to singles events a branching ratio of {gt}86% was deduced for neutron decay. The observation of isospin-violating neutron decay with a branching ratio close to 100% is in agreement with the expectation that the escape width ({Gamma}{sup {up_arrow}}) of the isobaric analog state in {sup 120}Sb is small compared to its spreading width ({Gamma}{sup {down_arrow}}). Triton spectra measured in coincidence with {gamma} rays from the deexcitation of the final nucleus display pronounced structures related to the thresholds for neutron emission, in agreement with the characteristics of calculatedmore » evaporation spectra.« less

Authors:
; ; ;  [1]; ;  [2]; ; ; ; ; ;  [3];  [4];  [5]
  1. Department of Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States)
  2. Kernfysisch Versneller Instituut, Zernikelaan 25, 9747 AA Groningen (Netherlands)
  3. Indiana University Cyclotron Facility, Bloomington, Indiana 47405 (United States)
  4. Department of Natural Sciences, University of Michigan, Dearborn, Michigan 48128 (United States)
  5. King Abdul-Aziz University, Jeddah (Saudi Arabia)
Publication Date:
OSTI Identifier:
249479
Resource Type:
Journal Article
Journal Name:
Physical Review, C
Additional Journal Information:
Journal Volume: 52; Journal Issue: 3; Other Information: PBD: Sep 1995
Country of Publication:
United States
Language:
English
Subject:
66 PHYSICS; ANTIMONY 120; ISOBARIC ANALOGS; TIN 120 TARGET; HELIUM 3 REACTIONS; NEUTRON EMISSION; TRITONS; CHARGE EXCHANGE; EVAPORATION; SPECTRA; BRANCHING RATIO; DETECTION; DE-EXCITATION

Citation Formats

Roberts, D A, Ashktorab, K, Becchetti, F D, Jaenecke, J, Harakeh, M N, van der Werf, S Y, Berg, G P.A., Foster, C C, Lisantti, J E, Rinckel, T, Stephenson, E J, Wells, S P, Nadasen, A, and Shaheen, S. Neutron decay from the isobaric analog state in {sup 120}Sb populated in {sup 120}Sn({sup 3}He,{ital t}){sup 120}Sb at {ital E}({sup 3}He) = 200 MeV, {theta} = 0{degree}. United States: N. p., 1995. Web. doi:10.1103/PhysRevC.52.1361.
Roberts, D A, Ashktorab, K, Becchetti, F D, Jaenecke, J, Harakeh, M N, van der Werf, S Y, Berg, G P.A., Foster, C C, Lisantti, J E, Rinckel, T, Stephenson, E J, Wells, S P, Nadasen, A, & Shaheen, S. Neutron decay from the isobaric analog state in {sup 120}Sb populated in {sup 120}Sn({sup 3}He,{ital t}){sup 120}Sb at {ital E}({sup 3}He) = 200 MeV, {theta} = 0{degree}. United States. https://doi.org/10.1103/PhysRevC.52.1361
Roberts, D A, Ashktorab, K, Becchetti, F D, Jaenecke, J, Harakeh, M N, van der Werf, S Y, Berg, G P.A., Foster, C C, Lisantti, J E, Rinckel, T, Stephenson, E J, Wells, S P, Nadasen, A, and Shaheen, S. Fri . "Neutron decay from the isobaric analog state in {sup 120}Sb populated in {sup 120}Sn({sup 3}He,{ital t}){sup 120}Sb at {ital E}({sup 3}He) = 200 MeV, {theta} = 0{degree}". United States. https://doi.org/10.1103/PhysRevC.52.1361.
@article{osti_249479,
title = {Neutron decay from the isobaric analog state in {sup 120}Sb populated in {sup 120}Sn({sup 3}He,{ital t}){sup 120}Sb at {ital E}({sup 3}He) = 200 MeV, {theta} = 0{degree}},
author = {Roberts, D A and Ashktorab, K and Becchetti, F D and Jaenecke, J and Harakeh, M N and van der Werf, S Y and Berg, G P.A. and Foster, C C and Lisantti, J E and Rinckel, T and Stephenson, E J and Wells, S P and Nadasen, A and Shaheen, S},
abstractNote = {The {sup 120}Sn({sup 3}He,{ital t}){sup 120}Sb charge-exchange reaction has been investigated at {ital E}({sup 3}He) = 200 MeV and {theta}{approx}0{degree} to study neutron decay from the isobaric analog state at {ital E}{sub {ital x}}=10.20 MeV in {sup 120}Sb. The low-energy neutrons (average energy {similar_to}0.85 MeV) were detected in coincidence with tritons observed in the focal plane of a high-resolution magnet spectrometer. Four small deuterated NE230 scintillation detectors were mounted at distances of 9.5 cm from the target resulting in an overall neutron detection efficiency including solid angle of {gt}1%. This efficiency was obtained by combining the measured dependence on neutron energy with a calculated neutron evaporation spectrum. From the measured ratio of coincidence to singles events a branching ratio of {gt}86% was deduced for neutron decay. The observation of isospin-violating neutron decay with a branching ratio close to 100% is in agreement with the expectation that the escape width ({Gamma}{sup {up_arrow}}) of the isobaric analog state in {sup 120}Sb is small compared to its spreading width ({Gamma}{sup {down_arrow}}). Triton spectra measured in coincidence with {gamma} rays from the deexcitation of the final nucleus display pronounced structures related to the thresholds for neutron emission, in agreement with the characteristics of calculated evaporation spectra.},
doi = {10.1103/PhysRevC.52.1361},
url = {https://www.osti.gov/biblio/249479}, journal = {Physical Review, C},
number = 3,
volume = 52,
place = {United States},
year = {1995},
month = {9}
}