Detector Testing

Current and near future space missions to the gas giant systems imply instrumentation that is specific to extreme space environments dominated by high background radiation or very long mission lifetimes.

The lifetime of a space plasma instrument is, beside other factors, highly limited by the lifetime of the detectors. The latter ones, on the other hand, are highly sensitive not only to the particle species of interest, but also to the background radiation.

Provoked by the IRF instruments for the JUICE mission, a small test facility has been established to test the degradation and lifetime of channel electron multipliers (CEMs) for the JDC and the JNA instrument.

The incident radiation is simulated by secondary electrons, which are emitted from an aluminum surface through UV photons. Eight UV-LEDs, thermally connected to the housing, serve as a source.

Technical specifications

Dimensions Chamber (inside): cross with $100 mm$ diameter, $216 mm$ length | Pressure; <$10^{-6} mbar$
Temperature: Room temperature
Logging: Automatic logging of counts
Manual logging of three temperatures in chamber, room temperature, pressure and pulse height profile possible
Vacuum Flanges: $2$ DN 100 ISO-K
Vacuum Feed Throughs: List of possible connectors available on request
Dimensions Mounting Plate: $ mm$ width, $ mm$ length
Material Mounting Plate: Aluminum
Pattern Mounting Plate: Individual for every detector
Particle Source: UV-photons converted to photo electrons through scattering
Optional Equipment: Residual gas analyzer (will influence the testing)

Four parallel PCBs placed on a metal disk. Standoffs between the PCBs provide spacing. White wires routed to each originating in the foreground. Two blue capacitors on mounted on each PCB. — Detector test facility with test articles

Photos: Philipp Wittmann, IRF