Megawatt, 1kHz PRF tunable gyrotron experiments

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:391239

Cross, A W; Phelps, A D.R.; Ronald, K; Spark, S N; Turnbull, S M ^[1]

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1. Univ. of Strathclyde, Glasgow (United Kingdom); and others

Repetitively pulsed and cw gyrotrons have hitherto used thermionic cathodes whereas cold cathode gyrotrons have normally operated as {open_quote} single shot{close_quote} or low pulse repetition frequency (PRF) devices. The novel results presented here demonstrate that a stacked Blumlein pulse generator driven cold cathode gyrotron developing > 1 MW per pulse (f=90 GHz) may be run with a repetition frequency of 1 kHz over timescales of >30 seconds. A short burst PRF of 2 kHz was also observed. The PRF of the system was limited to 2 kHz by the High Voltage (HV) DC power supply. The gyrotron was based on a two-electrode configuration comprising of a field-immersed, field emission cold cathode and a shaped anode cavity. A superconducting magnet was used to produce the homogeneous intra-cavity magnetic field and a stacked Blumlein pulse generator was used to drive the electron beam. This pulse generator was capable of producing an output voltage up to 300 kV with a 20ns rise time, a 100ns flat top, and a 20ns fall time. The output impedance was 200{Omega} and the energy stored in the generator at a charging voltage of 60 kV was 5.4J. No degradation effects on the mm-wave output was evident due to diode recovery time throughout this series of results. A subsequent conclusion is that the recovery time in the cold cathode gyrotron is less than 500{mu}s.

• OSTI ID: 391239
• Report Number(s): CONF-951240--
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
COLD CATHODE TUBES
GHZ RANGE 01-100
HIGH-VOLTAGE PULSE GENERATORS
MICROWAVE AMPLIFIERS
POWER RANGE 01-10 MW
PULSE TECHNIQUES