The X-Ray Photon Efficiency of a Multiplier Tube

Abstract

The design and operation of a 12-stage electrostatic multiplier tube as a photon counter are discussed. The tube has a pure tantalum photoelectric surface, the multiplying electrodes being covered with oxidized beryllium. With 300 volts between successive electrodes the tube has a background counting rate of about 3 to 5 pulses per minute and records about one photon in 500 at a wave-length of 10−8 cm. The multiplication is about 18,000.