Molecular-Flow Properties of RIB Type Vapor-Transport Systems Using a Fast-Valve

Journal Article · Wed Jan 01 00:00:00 EST 2014 · Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms

DOI:https://doi.org/10.1016/j.nimb.2014.02.129· OSTI ID:1126955

Alton, Gerald D ^[1]; Bilheux, Hassina Z ^[1]; Zhang, Y. ^[2]; Liu, Yuan ^[1]

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1. ORNL
2. Oak Ridge National Laboratory (ORNL)

The advent of the fast-valve device, described previously, permits measurement of molecular-flow times of chemically active or inactive gaseous species through radioactive ion beam (RIB) target ion source systems, independent of size, geometry and materials of construction. Thus, decay losses of short-half-life RIBs can be determined for a given target/vapor-transport system in advance of on-line operation, thereby ascertaining the feasibility of the system design for successful processing of a given isotope. In this article, molecular-flow-time theory and experimentally measured molecular-flow time data are given for serial- and parallel-coupled Ta metal RIB vapor-transport systems similar to those used at ISOL based RIB facilities. In addition, the effect of source type on the molecular-flow time properties of a given system is addressed, and a chemical passivation method for negating surface adsorption enthalpies for chemically active gaseous species on Ta surfaces is demonstrated.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Holifield Radioactive Ion Beam Facility (HRIBF)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1126955
• Journal Information: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, Vol. 329; ISSN 0168-583X
• Country of Publication: United States
• Language: English