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 |