Experiments with a prototype titanium hot cavity surface ionization source intended for electromagnetic separation of radioactive samarium and other lanthanide elements

Brad D Jeffries; Valentina O'Donnell; Peter Norgard; J David Robertson; Barry Higgins; John Gahl

doi:10.1016/j.apradiso.2021.109621

Experiments with a prototype titanium hot cavity surface ionization source intended for electromagnetic separation of radioactive samarium and other lanthanide elements

Appl Radiat Isot. 2021 Apr:170:109621. doi: 10.1016/j.apradiso.2021.109621. Epub 2021 Feb 1.

Authors

Brad D Jeffries¹, Valentina O'Donnell², Peter Norgard³, J David Robertson⁴, Barry Higgins³, John Gahl⁵

Affiliations

¹ University of Missouri - College of Engineering, 207 Naka Hall, Columbia, MO, 65211, USA. Electronic address: bdj8zb@umsystem.edu.
² University of Missouri - College of Engineering, 207 Naka Hall, Columbia, MO, 65211, USA.
³ University of Missouri Research Reactor Center (MURR), 1513 Research Park Drive, Columbia, MO, 65211, USA.
⁴ University of Missouri Research Reactor Center (MURR), 1513 Research Park Drive, Columbia, MO, 65211, USA; University of Missouri - Department of Chemistry, 601 South College Ave, Columbia, MO, 65211, USA.
⁵ University of Missouri - College of Engineering, 207 Naka Hall, Columbia, MO, 65211, USA; University of Missouri Research Reactor Center (MURR), 1513 Research Park Drive, Columbia, MO, 65211, USA.

PMID: 33548814
DOI: 10.1016/j.apradiso.2021.109621

Abstract

This paper reports experimental results of a prototype titanium surface ionization source. For the first time, a lanthanide ion beam has been produced with a surface ionizer composed completely of titanium metal. Titanium does not readily activate with neutron irradiation. This offers the potential for inserting an ion source made of titanium directly into a reactor with a pre-loaded non-radioactive lanthanide target. This seamlessly integrates target irradiation with isotope separation, eliminating post irradiation sample manipulation. Samarium ion beam currents up to 960 nA have been produced in an off-line test bench equipped with rudimentary beam optics. This is a crucial step toward the development of an ionization source adopted for the electromagnetic isotope separator (EMIS) facility, which has been designed for high throughput separations of radioactive ¹⁵³Sm and other lanthanides of interest in the field of nuclear medicine. The ion current and important factors affecting the performance of the ion source, such as the ionizer temperature and thermal gradient, are discussed. The experimental results are presented together with a discussion of future modifications to optimize the overall surface ionization source performance.

Keywords: (153)Sm (samarium-153); Electromagnetic isotope separator; Medical radioisotopes; Surface ionization source.