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The ion source is optimized on 40Ar9+ (black spectrum). This is a reference spectrum with 160 µA of Ar9+. After a plasma chamber replacement, the ion source is validated if the Ar9+ beam intensity is greater or equal to 120 µA. A record intensity of 245 µA has been reported on the graph below (red spectrum) although no clear conclusion could be made : much better distribution due to a magnesium wall coating effect, or due to the higher RF power injected into the plasma ?
Phoenix V2 - 18 GHz :
2012-02-24 15:25. Best spectrum obtained at LPSC-Grenoble equiped with the SPIRAL 2 beam line, optomized on 40Ar14+ (48 µA). RF power 1.63kW (69 reflected), Source voltage 60.0kV/6.3mA, biased disk : 53V/0.3mA, buffer gaz O2, ext. pressure 2.1E-8mbar, coils 1194A/-1117A/1250A. Optics SOL11=167.4 A, D11=78.06 A, Q11=24.06, Q12=49.40 A, Q13=64.50 A.
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