Development of a high-energy crowbar for the Los Alamos free-electron laser

Conference · Thu Jan 01 04:00:00 EST 1987

DOI:https://doi.org/10.1016/0168-9002(88)90228-8· OSTI ID:6134213

Hornkohl, J O; Lynch, M T

A 135-kV, 2.5-..mu..s crowbar has been developed to protect the TH2095A klystrons used on the Los Alamos free-electron laser. The klystron power supply consists of a 135-kV, 8.75-..mu..F capacitor bank with a stored energy of approximately 80 kJ. The TH2095A specifications require that the dissipated energy in a klystron arc be limited to less than 10J. The crowbar design is based upon a series stack of pressurized spark gaps immersed in an oil tank. The spark gaps are triggered by an SCR-switched high-voltage trigger transformer. Input triggers are provided by current-monitoring transformers. The following currents are sensed for input triggers: total system current, integrated system current (long pulse sensing), cathode current, and modulator-anode current. Trigger levels are set to approximately 150% of nominal current levels. Unique features of this design are its modulator-anode trigger, noise immunity, and ability to print out the energy dissipated in the klystron arc. Typical operation of this system limits the energy dissipated in an arc to less than 2J. This paper describes the original design requirements, mechanical layout and fabrication, main trigger circuit design, modulator-anode trigger design, noise immunity circuit, integrated energy monitor, diagnostics, and recent developments. Performance data are also included. 1 ref., 6 figs.

• Research Organization: Los Alamos National Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6134213
• Report Number(s): LA-UR-87-2882; CONF-8709110-2; ON: DE87014748
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420300* -- Engineering-- Lasers-- (-1989)
43 PARTICLE ACCELERATORS
430303 -- Particle Accelerators-- Experimental Facilities & Equipment
CURRENTS
DESIGN
ELECTRIC ARCS
ELECTRIC CURRENTS
ELECTRIC DISCHARGES
ELECTRON TUBES
ELECTRONIC EQUIPMENT
EQUIPMENT
EQUIPMENT PROTECTION DEVICES
FREE ELECTRON LASERS
KLYSTRONS
LASERS
MICROWAVE EQUIPMENT
MICROWAVE TUBES
SPARK GAPS