Helium jet ion source in FRIB era

Gas stopping of reaction products has a key feature, fixed holdup time independent of element, making it possible to provide ion beams of essentially all element. Two classes of gas stopping have been developed over the last 40+ years, broadly classified as He Jet and Ion guide. A primary difference between these two techniques is the physical separation of the stopping cell and the ionization cell in the He Jet technique. In this paper we point out two applications of current interest where this physical separation is crucial: 1) ionization (ion beam intensity) is independent of primary beam intensity and 2) multiuser capability for accelerator facilities. Specific examples will be described.