SEM-7B Secondary Electron Multiplier

SEM-7B secondary electron multiplier with 25 mm active area diameter is intended for the detection of particulate and other short-wavelength electromagnetic radiation fluxes as part of scientific and industrial equipment, including space instruments.

Rimmed microchannel plates 25-10A MCPs with 33 mm overall diameter, 25 mm active area diameter and 10 µm channel diameter are used in this device.


Schematic diagram

Basic parameters

Parameter, unit Value
min max
Supply voltage at ≥ 1×107 gain, V   2300
Single electron pulse height resolution, %   120
Dark count rate density, count/sec×cm2   3
Overall dimensions
Maximum diametermm50
Input window areacm25
Reference data
Pulse leading edge rise timens0.6–0.7
Full width at half maximum (FWHM)ns1.5–2