Harvesting krypton isotopes from the off-gas of an irradiated water target to generate 76Br and 77Br

Hannah K Clause; Katharina A Domnanich; Chloe Kleinfeldt; Morgan Kalman; Wesley Walker; Chirag Vyas; E Paige Abel; Gregory W Severin

doi:10.1038/s41598-022-05500-8

Harvesting krypton isotopes from the off-gas of an irradiated water target to generate ⁷⁶Br and ⁷⁷Br

Sci Rep. 2022 Jan 26;12(1):1433. doi: 10.1038/s41598-022-05500-8.

Authors

Hannah K Clause^{1

2}, Katharina A Domnanich^{1

2}, Chloe Kleinfeldt^{1

2}, Morgan Kalman^{1

2}, Wesley Walker^{1

2}, Chirag Vyas^{1

2}, E Paige Abel^{1

2}, Gregory W Severin^{3

4}

Affiliations

¹ Department of Chemistry, Michigan State University, 578 S. Shaw Ln., East Lansing, MI, USA.
² Facility for Rare Isotope Beams, Michigan State University, 640 S. Shaw Ln., East Lansing, MI, USA.
³ Department of Chemistry, Michigan State University, 578 S. Shaw Ln., East Lansing, MI, USA. gwseverin@chemistry.msu.edu.
⁴ Facility for Rare Isotope Beams, Michigan State University, 640 S. Shaw Ln., East Lansing, MI, USA. gwseverin@chemistry.msu.edu.

Abstract

A flowing-water target was irradiated with a 150 MeV/nucleon beam of ⁷⁸Kr at the National Superconducting Cyclotron Laboratory to produce ⁷⁷Kr and ⁷⁶Kr. Real-time gamma-imaging measurements revealed the mass transport of the krypton radioisotopes through the target-water processing, or "isotope harvesting", system. The production rates were determined to be 2.7(1) × 10^-4 nuclei of ⁷⁶Kr and 1.18(6) × 10^-2 nuclei of ⁷⁷Kr formed per incident ⁷⁸Kr ion. Utilizing an off-gas processing line as part of the isotope harvesting system, a total of 7.2(1) MBq of ⁷⁶Kr and 19.1(6) MBq of ⁷⁷Kr were collected in cold traps. Through the decay, the daughter radionuclides ⁷⁶Br and ⁷⁷Br were generated and removed from the traps with an average efficiency of 77 ± 12%. Due to the differences in half-lives of ⁷⁶Kr and ⁷⁷Kr, it was possible to isolate a pure sample of ⁷⁶Br with 99.9% radionuclidic purity. The successful collection of krypton radioisotopes to generate ⁷⁶Br and ⁷⁷Br demonstrates the feasibility of gas-phase isotope harvesting from irradiated accelerator cooling-water. Larger-scale collections are planned for collecting by-product radionuclides from the Facility for Rare Isotope Beams.

Abstract

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