MEVVA is one of the first ion sources in the world based on vacuum arc plasma production principle. It was developed by I.G. Brown in Berkeley National Laboratory (LBNL, USA) and came to GSI in 1995. Since that time the MEVVA ion source was upgraded and optimized for longer and more stable operation.
The cathode flange of the ion source has a revolver design and is equipped with 17 cathodes. The ion source comprises two magnetic coils 0.1 and 0.2 Tesla respectively. They are used to confine the plasma in the discharge region in order to control the charge-state distribution of ions as well as focus the plasma in the drift region.
The MEVVA ion source works with all types of ductile conductive metals. The typical lifetime of MEVVA is 1 week in synchrotron operation mode.
|Plasma generator||Dimensions: ø 40 x 110 mm|
|Extraction system||Triode, Multi aperture: 13 x ø 3 mm|
|Aspect ratio: 0.5|
|Extraction voltage: up to 33 kV|
|Post-acceleration: up to 150 kV|
|Operation parameters||Arc current: up to 2000 A|
|Emission current density: up to 170 mA/cm2|
|Typical duty cycle: 1 Hz, 1 ms|
|Working elements||O2, Mg, Ca, Ti, Ni, Mo, Ag, Nd, Ta|
|History||In operation at GSI: since 1999|
|Developer: LBNL (USA), I.G. Brown|