New developments in pulsed power technology and associated electron beam transport mechanisms at the United Kingdom Atomic Weapons Establishment

• Published in: Digest of Technical Papers. 12th IEEE International Pulsed Power Conference. (Cat. No.99CH36358) Vol. 2; pp. 1003 - 1006 vol.2
• Main Authors: Birrell, A.R., Carpenter, P.G., Cooper, G.M., Davitt, R., Edwards, R.D., Goldsack, T.J., McLean, J., Sinclair, M.A.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 1999
• Subjects: Capacitors; Coaxial components; Electron beams; Electron tubes; Insulation; Power generation; Pulse generation; Radiography; Spark gaps; Voltage
• ISBN: 0780354982; 9780780354982
• DOI: 10.1109/PPC.1999.823687

The Pulsed Power Group at AWE is interested in the generation of small, intense, multi-megavolt X-ray sources for radiographic applications. One of them, E Minor, is used for research into electron beam transport and focusing studies. E Minor consists of three main sections: (1) a Marx generator incorporating 84 0.7 /spl mu/F capacitors that are slowly charged in parallel to 50 kV and then quickly switched and discharged through a series configuration via triggered spark gaps producing an output voltage of 4.2 MV; (2) this output voltage in turn pulse charges a Blumlein pulse forming line (PFL). The Blumlein PFL consists of three coaxial cylinders, 3.2 m, 2.0 m and 1.0 m in diameter. The output of the PFL is a 40 ns long 5.3 MV electrical pulse driving 38 kA into a typical electron beam load; and (3) the X-ray tube has sixteen, 92 mm thick, Lucite sections angled at 45 degrees to the electric field which, with the spacer rings, is 1.55 m long and 1.2 m in diameter. The vacuum housing acts as the outer cylinder of a magnetically insulated coaxial transmission line (MITL). The central conductor of this MITL supports the cathode stalk, and forms a line having an impedance of 190 ohms.