Edition 4, No. 4 August 30, 1996 Price: FREE

Editor:  Carl J. Gross
Contributor: J. R. Beene

1. First Radioactive Ion Beam Accelerated at HRIBF

At 1 PM today the initial goal of the low intensity commissioning phase of the HRIBF was achieved when a radioactive 70-As beam was produced, transported to the 25 MeV tandem accelerator, and accelerated to an energy of 140 MeV. The 70-As was produced with the 70-Ge(p,n) reaction on a liquid Ge target using a low intensity (~50 nA) proton beam from ORIC. After mass analysis and charge exchange, the 70-As beam, together with a 70-Ge pilot beam, was accelerated off the RIB injector platform to an energy of 200 keV and deposited on a moving tape system where the 70-As content was determined by detecting characteristic decay gamma-rays. The tape system was then retracted and the beam was transported to the tandem, accelerated, and the 70-As decay was again observed. Quantitative details will be provided next week.

Additional copies of the newsletter and more information about HRIBF can be found on the World Wide Web at

Jerry D. Garrett, Scientific Director    |Email:
Mail Stop 6368                           |Tel:   (423) 576-5489

Carl J. Gross, Scientific Liaison        |Email:
Mail Stop 6371                           |Tel:   (423) 576-7698

Holifield Radioactive Ion Beam Facility  |Tel:   (423) 574-4113
Oak Ridge National Laboratory            |Fax:   (423) 574-1268
Oak Ridge, TN 37831