A flat-cathode thermionic injector for the PHERMEX Radiographic Facility

Conference · Tue Jun 01 04:00:00 EDT 1993

OSTI ID:10161412

Kauppila, T; Builta, L; Burns, M; Gregory, W; Honaberger, D; Watson, S ^[1]; Hughes, T ^[2]

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1. Los Alamos National Lab., NM (United States)
2. Mission Research Corp., Albuquerque, NM (United States)

The PHERMEX (Pulsed High-Energy Radiographic Machine Emitting X-rays) standing-wave linear accelerator is a high-current electron beam generator used for flash-radiography. An improved electron gun has been designed employing a flat-thermionic cathode to replace the existing Pierce-geometry gun. The flat cathode yields increased current with the same applied voltage and cathode area as the Pierce gun. The ISIS code simulations indicate a beam current of 1.5 kA at 600 kV. The new geometry also reduces the probability for high voltage breakdown in the A-K gap. A reentrant magnet captures the expanding electron beam and a bucking coil nulls cathode-tinge field. A third coil is used to optimize the extraction field profile and reduce the effect of nonlinear space charge on the beam emittance. Time-resolved measurements of beam current and voltage have been made. In addition, a streak camera was used to measure beam emittance and spatial profile. Comparisons of measurements with simulations are presented.

• Research Organization: Los Alamos National Lab., NM (United States); Mission Research Corp., Albuquerque, NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 10161412
• Report Number(s): LA-UR--93-1715; CONF-930511--104; ON: DE93014584
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
430302
440101
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
BEAM INJECTION
BEAM TRANSPORT
CATHODES
ELECTRON BEAMS
ELECTRON GUNS
GENERAL DETECTORS OR MONITORS AND RADIOMETRIC INSTRUMENTS
INDUSTRIAL RADIOGRAPHY
INJECTION AND EXTRACTION SYSTEMS
LINEAR ACCELERATORS
THERMIONIC DIODES