Beam particle identification and tagging of incompletely stripped heavy beams with HEIST

A K Anthony; C Y Niu; R S Wang; J Wieske; K W Brown; Z Chajecki; W G Lynch; Y Ayyad; J Barney; T Baumann; D Bazin; S Beceiro-Novo; J Boza; J Chen; K J Cook; M Cortesi; T Ginter; W Mittig; A Pype; M K Smith; C Soto; C Sumithrarachchi; J Swaim; S Sweany; F C E Teh; C Y Tsang; M B Tsang; N Watwood; A H Wuosmaa

doi:10.1063/5.0068180

Beam particle identification and tagging of incompletely stripped heavy beams with HEIST

Rev Sci Instrum. 2022 Jan 1;93(1):013306. doi: 10.1063/5.0068180.

Authors

A K Anthony¹, C Y Niu¹, R S Wang¹, J Wieske¹, K W Brown¹, Z Chajecki², W G Lynch¹, Y Ayyad¹, J Barney¹, T Baumann¹, D Bazin¹, S Beceiro-Novo¹, J Boza², J Chen¹, K J Cook¹, M Cortesi¹, T Ginter¹, W Mittig¹, A Pype¹, M K Smith¹, C Soto², C Sumithrarachchi¹, J Swaim², S Sweany¹, F C E Teh¹, C Y Tsang¹, M B Tsang¹, N Watwood¹, A H Wuosmaa³

Affiliations

¹ National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA.
² Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008, USA.
³ Department of Physics, University of Connecticut, Storrs, Connecticut 06269, USA.

PMID: 35104937
DOI: 10.1063/5.0068180

Abstract

A challenge preventing successful inverse kinematics measurements with heavy nuclei that are not fully stripped is identifying and tagging the beam particles. For this purpose, the HEavy ISotope Tagger (HEIST) has been developed. HEIST utilizes two micro-channel plate timing detectors to measure the time-of-flight, a multi-sampling ion chamber to measure energy loss, and a high-purity germanium detector to identify isomer decays and calibrate the isotope identification system. HEIST has successfully identified ¹⁹⁸Pb and other nearby nuclei at energies of about 75 MeV/A. In the experiment discussed, a typical cut containing 89% of all ¹⁹⁸Pb⁸⁰⁺ in the beam had a purity of 86%. We examine the issues of charge state contamination. The observed charge state populations of these ions are presented and, using an adjusted beam energy, are well described by the charge state model GLOBAL.