ISSN:
1089-7623
Source:
AIP Digital Archive
Topics:
Physics
,
Electrical Engineering, Measurement and Control Technology
Notes:
A new 10 GHz electron cyclotron resonance ion source (ECRIS) has been constructed and commissioned for the ATLAS accelerator. This new source replaces the original ATLAS ECRIS that has been in operations since 1987. The goal of this upgrade project was to significantly improve the source performance while maintaining maximum operational flexibility for solid material feeds. The new source design includes a large magnetic-field gradient, aluminum plasma chamber, and bias disk following modern ECRIS design concepts. Eight solenoid coils from the original source along with a new iron yoke form the magnetic mirror. Hall Probe measurements showed the axial B field to be within 1% of the POISSON design model calculated at 400 A per coil. The injection and extraction mirror ratios are approximately 4.4 and 2.9, respectively, with a minimum field of 3.0 kG. A new aluminum plasma chamber houses the NdFeB hexapole magnets, which are encased in austenitic stainless steel to allow for direct water cooling. An open hexapole configuration provides six radial access ports, 1.7 cm×4.1 cm, to the plasma chamber for solid material feeds and vacuum pumping at an estimated rate of 20 l/s per radial port. Measurements of the hexapole field near the plasma chamber wall, 4 cm in radius, were within 13% of the designed B field of 9.3 and 5.7 kG along the poles and pole gaps, respectively. The first plasma in the new source was obtained on October 10, 2000. Already it has exceeded the best 16O6+ beam current obtained from the original ECR-I by a factor of roughly 2.3, achieving 140 e μA with a biased disk. The source is back in regular operation and ATLAS experiment runs have been performed with He, O, Ar, Kr, Ni, and Zr. © 2002 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1430510
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