Resistance Strip Magnetic Photomultiplier for the Extreme Ultraviolet

The performance of a windowless resistance strip magnetic multiplier for detection of extreme ultraviolet is described. The detector is characterized by a high spectral sensitivity for wavelengths below 1400 A and a low sensitivity to longer wavelength radiation. It is reproducible in spectral response and gain after exposure to air or after cleaning. A current gain of 108 can be realized with the multiplier for an over-all voltage of approximately 2000 v. The photomultiplier can be operated as a photoelectron counter with a well-defined counting plateau for pressures below 10−4 mm Hg. The background counting rate of the detector, at room temperature and typical operation in the plateau region, is less than 0.1 count/sec.