Recent X-ray diode and magnetically insulated transmission line experiments performed on the 5.5 MV Superswarf machines at AWE Aldermaston

The Pulsed Power Group at AWE is interested in the generation of small, intense, multi-megavolt X-ray sources for radiographic applications. Two of them, the Superswarfs, are maintained as facility machines and used by other groups for radiographic experiments, but upon which we are permitted to conduct diode research experiments. These machines have been using a paraxial diode for a number of years. This is a passive method of focussing the electron beam to provide a small X-ray source. Within the last few years this has been enhanced to provide a smaller source, but with a slight loss in dose. The magnetically immersed diode is being investigated as an alternative method to focussing the electron beam onto a tantalum target. The external magnetic field, up to 25 T, is produced by a solenoid which is driven by a 418 /spl mu/F, 22 kV capacitor bank. The best Bz shot to date has produced 82 R @ 1 m with a 4.2 mm diameter spot size.