ISSN:
1089-7623
Source:
AIP Digital Archive
Topics:
Physics
,
Electrical Engineering, Measurement and Control Technology
Notes:
The 10 GHz ECR-I ion source at ATLAS is being modified to create a small inner volume within the main plasma chamber to reduce the residual helium background gas load. This effort is part of an experiment to measure the residual concentration of 3He in highly isotopically enriched 4He samples. The modification consists of a new extractor electrode on which is integrally mounted a 2.5-cm-diam quartz tube of approximately 8 cm length. Energizing just the extraction coil produces an ECR only inside the quartz volume. The quartz tube is pumped only through the 1-mm-diam extraction hole. rf power is provided by propagation through the main plasma tank acting as a multimode waveguide. The source must operate in the pressure regime of 10–200 mTorr in order to achieve sufficient sensitivity to measure a 3He/4He ratio of approximately 1×10−15. Results of these tests and the operation of the source in this highly unusual mode will be presented. © 2002 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1432461
