Physical picture of immersed diode experiments on HERMES III and SABRE

Summary form only given. A needle-like, high-current, electron beam has been produced on the Hermes III and SABRE accelerators at SNL using inductive voltage adder (IVA) technology, and a diode consisting of a needle cathode and a planar anode/bremsstrahlung converter which are both fully immersed in a strong solenoidal magnetic field (12-50 T). Desired nominal parameters are 10 MV, 40 kA, 0.5 mm radius cathode, and 5-35 cm anode-cathode gaps. High dose and small X-ray spot size are required for radiography applications. Results are presented of initial experiments on Hermes III and SABRE, which have produced doses up to 1 kRad@1 meter, and at lower doses, spot sizes as small as 1.7 mm diameter.