RAPID Electron Spectrometer IES
Electrons with energies from 20 keV to 400 keV are measured with the Imaging
Electron Spectrometer (IES). Advanced microstrip solid state detectors
having a 0.5 cm × 1.5 cm planar format with three individual elements
form the image plane for three acceptance "pin-hole" systems. Each system
divides a 60° segment into 3 angular intervals. A schematic
cross-section of an IES pin-hole camera is presented the figure. Three
of these detectors arranged in the configuration shown provide electron
measurements over a 180° fan.
The 800 micron thick ion-implant solid state devices are covered with
a 450 µg/cm2 (Si eq) absorbing window which eliminates
ions up to 350 keV through the mass dependent range-energy relationship.
The 9 individual strips on the three focal plane detectors are interrogated
by a multichannel switched-charge/voltage-converter (SCVC) in monolythic
technology. The SCVC provides for each particle coded information on the
strip number and particle energy. This primary information is transferred
to the DPU for further evaluation.