Bendix manufactured this open cathode electron multiplier and detector circa early 1960s, typical of detectors flown on early OSO spacecraft. The cathode is not enclosed in a glass or other insulating envelope since it was designed to work in the vacuum of space. A sufficiently energetic UV photon striking the cathode at the entrance grid of the device results in the release of one or more electrons. The first of a series of permanent magnets then directs the emitted electrons onto a strip of specially coated glass. This results in the release of a large number of secondary electrons. Repetition of this process leads to a cascade of charge with the resulting current gain as high as 10 million fold.
The detector was transferred to NASM by NASA (GSFC) in 1995.
Credit Line:
Transferred from the National Aeronautics and Space Administration
