TY - JOUR
T1 - Electron spectrometer for electric monopole (E0) transition studies in nuclei
AU - Avaa, A. A.
AU - Jones, P.
AU - Usman, I. T.
AU - Chisapi, M. V.
AU - Kibédi, T.
AU - Zikhali, B. R.
AU - Msebi, L.
N1 - Publisher Copyright:
© 2020
PY - 2020/6/1
Y1 - 2020/6/1
N2 - The study of electric monopole (E0) transitions between two 0+ states is important because the monopole strength carries vital information about the nuclear structure due to its direct link with the mean squared charge radius r2 and quadrupole deformation parameter β. Therefore, the measurement of internal conversion electrons (ICE) or internal pair formation (IPF) is crucial for E0 transition studies. Transitions between 0+ states do not change angular momentum. Hence, single-photon emission is forbidden, but can decay by conversion electrons or pair formation and two-photon emission which is mostly negligible. In order to implement E0 studies at iThemba LABS, an electron spectrometer that uses a solenoidal magnetic field acting as a lens and a Si(Li) detector has been refurbished and characterized using calibration sources of ICE. Figures of merit have been extracted and compared with simulations. The spectrometer coupled with an array of LaBr3:Ce detectors and Low Energy Photon Spectrometers (LEPS) was successfully implemented for in-beam experiments. Measurements of internal conversion coefficients (ICC) and monopole strengths extracted from in-beam measurements of 72As, 72Ge, and 72Se are presented.
AB - The study of electric monopole (E0) transitions between two 0+ states is important because the monopole strength carries vital information about the nuclear structure due to its direct link with the mean squared charge radius r2 and quadrupole deformation parameter β. Therefore, the measurement of internal conversion electrons (ICE) or internal pair formation (IPF) is crucial for E0 transition studies. Transitions between 0+ states do not change angular momentum. Hence, single-photon emission is forbidden, but can decay by conversion electrons or pair formation and two-photon emission which is mostly negligible. In order to implement E0 studies at iThemba LABS, an electron spectrometer that uses a solenoidal magnetic field acting as a lens and a Si(Li) detector has been refurbished and characterized using calibration sources of ICE. Figures of merit have been extracted and compared with simulations. The spectrometer coupled with an array of LaBr3:Ce detectors and Low Energy Photon Spectrometers (LEPS) was successfully implemented for in-beam experiments. Measurements of internal conversion coefficients (ICC) and monopole strengths extracted from in-beam measurements of 72As, 72Ge, and 72Se are presented.
KW - Conversion coefficient
KW - Electron spectrometer
KW - Internal conversion electrons
KW - Monopole strength
KW - Transmission
UR - http://www.scopus.com/inward/record.url?scp=85082660658&partnerID=8YFLogxK
U2 - 10.1016/j.nima.2020.163809
DO - 10.1016/j.nima.2020.163809
M3 - Article
SN - 0168-9002
VL - 964
JO - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
JF - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
M1 - 163809
ER -