Radiation field from an extended planar-anode diode on HERMES III

Abstract

The bremsstrahlung field from an extended planar-anode diode with an annular cathode tip on the the 16-TW HERMES III electron accelerator is measured and compared with predictions of the MAGIC-CYLTRAN model. Measurements confirm predictions and demonstrate that the diode provides a versatile large-area source of gamma radiation. Versatility is obtained by adjustment of the anode-cathode gap, which affects electron trajectories while simultaneously maintaining constant diode impedance. The adjustment permits the generation of average dose rates from about 1.2*10/sup 12/ rad/s over 3100 cm/sup 2/ to about 5.6*10/sup 12/ rad/s over 700 cm/sup 2/ without destruction of the bremsstrahlung target.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>