CHORDIS is a filament driven ion source with a small plasma chamber designed for production of singly-charged ions. It has a single filament holder placed on the beam axis (in the middle of the plasma chamber) and is equipped with 6 spiral filaments made of tungsten or tantalum. The confining multi-cusp field is realized by 20 SmCo-magnets (1.8 Tesla). The specificity of CHORDIS source is the electrostatic electron repeller (reflector electrode) and the negatively biased plasma electrode.
Plasma generator | Dimensions: ø 90 x 80 mm |
Multi-cusp magnetic confinement | |
Magnetic electron repeller | |
6 x W-filaments | |
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 400 A |
Emission current density: up to 180 mA/cm2 | |
Typical duty cycle: 5 Hz, 1 ms | |
Maximum duty factor: 100% | |
Working gas | H2, D2, CH4, N2, O2, Ne, Ar, Kr, Xe |
History | In operation at GSI: since 1984 |
Developer: GSI, R. Keller |