CHORDIS (Cold or HOt Reflex Discharge Ion Source)

Owned by Maimone Fabio
Jan 18, 2018

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 generatorDimensions: ø 90 x 80 mm
 Multi-cusp magnetic confinement
 Magnetic electron repeller
 6 x W-filaments
Extraction systemTriode, Multi aperture: 13 x ø 3 mm
 Aspect ratio: 0.5
 Extraction voltage: up to 33 kV
 Post-acceleration: up to 150 kV
Operation parametersArc 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 gasH2, D2, CH4, N2, O2, Ne, Ar, Kr, Xe
HistoryIn operation at GSI: since 1984
 Developer: GSI, R. Keller