Proposal for an Optically Pumped 3He++ Polarized Ion Source Development for the NICA Collider

Abstract

A proposal for development of a high intensity polarized source of ³He⁺⁺ ions is based on injection of polarized by metastability exchange optical pumping (MEOP) technique ³He gas into the EBIS (electron beam ion source) for ionization and accumulation of ³He⁺⁺ ions. A high magnetic field of ~5.0 T in the source should preserve the polarization during ionization process. This paper presents a scheme of the EBIS for ³He⁺⁺ ions production, magnetic field configuration, electron gun, electron beam focusing system, injection system to the source drift tube, which also works as a storage cell to increase ionization efficiency, the ³He cryogenic gas purification and storage system. It will also be possible to inject other gases into this source by a pulse valve into the drift-tube (storage cell) and produce multicharged ions, including Xe²⁸⁺ ions. With the addition of external injection of a single-charge solid heavy ion beam into the EBIS, this source can also produce multicharged ion beams up to Au³³⁺ and Bi³⁸⁺ with a full charge of more than 10 nC/cycle.