Gamma-Ray Circular Polarization Analyzer Using a Rapidly Alternating Magnetic Field

Abstract

Gamma rays from substances with half-lives approaching 0.1 sec may be analyzed using a magnet whose saturated field reverses in 0.4 msec. Laminated magnetic material and transistor circuitry are used to achieve the fast field reversal. The magnet consists of 4-mil Supermendur tape wound on a toroidal core. The high permeability and low loss of this material permits it to be driven by a single turn at reasonable currents. The circuit uses a low voltage, high current power supply, and charging inductors to provide the necessary voltage pluses. These pulses are developed across switches consisting of ten 2N1358 power transistors operated in parallel. The system has operated 2000 h without a failure.