Far From 'Easy' Spectroscopy with the 8π and GRIFFIN Spectrometers at TRIUMF-ISAC

[摘要] The 8π spectrometer, installed at the TRIUMF-ISAC facility, was the world's most sensitive γ-ray spectrometer dedicated to β-decay studies. A description is given of the 8π spectrometer and its auxiliary detectors including the plastic scintillator array SCEPTAR used for β-particle tagging and the Si(Li) array PACES for conversion electron measurements, its moving tape collector, and its data acquisition system. The recent investigation of the decay of124Cs to study the nuclear structure of124Xe, and how the β-decay measurements complemented previous Coulomb excitation studies, is highlighted, including the extraction of the deformation parameters for the excited 0+bands in124Xe. As a by-product, the decay scheme of the (7+)124Cs isomeric state, for which the data from the PACES detectors were vital, was studied. Finally, a description of the new GRIFFIN spectrometer, which uses the same auxiliary detectors as the 8π spectrometer, is given.

[发布机构] Department of Physics, University of Guelph, Guelph; ON; N1G2W1, Canada^1;Physics Division, Oak Ridge National Laboratory, Oak Ridge; TN; 37831, United States^2;Department of Chemistry, Simon Fraser University, Burnaby; BC; V5A1S6, Canada^3;TRIUMF, 4004 Wesbrook Mall, Vancouver; BC; V6T 2A3, Canada^4;Department of Physics, Colorado School of Mines, Golden; CO; 80401, United States^5;Department of Physics, University of the Western Cape, P/B X17, Bellville; ZA-7535, South Africa^6;IThemba LABS, P.O. Box 722, Somerset West; 7129, South Africa^7;School of Physics, Georgia Institute of Technology, Atlanta; GA; 30332-0430, United States^8;Departments of Chemistry and Physics and Astronomy, University of Kentucky, Lexington; KY; 40506-0055, United States; (10) Department of Physics and Astronomy, Louisiana State University, Baton Rouge; LA; 70803, United States; (11) National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing; MI; 48824, United States; (12) DESY Photon Science, Notkestrasse 85, Hamburg; D-22607, Germany; (13) Department of Physics, University of Ottawa, 150 Louis-Pasteur, Ottawa; ON; K1N 6N5, Canada; (14) Instituut voor Kern-en Stralingsfysica, K.U. Leuven, Celestijnenlaan 200D, Leuven; B-3001, Belgium; (15) Grand Accélérateur National d'Ions Lourds (GANIL), CEA/DSM-CNRS/IN2P3, Bvd Henri Becquerel, Caen; 14076, France; (16) Department of Physics, Tennessee Technological University, Cookeville; TN; 38505, United States^9

[关键词] Beta particles;Conversion electrons;Coulomb excitation;Decay scheme;Deformation parameter;Isomeric state;Nuclear structure;Plastic scintillator arrays