Intense microwave radiation from a repetitive backward-wave oscillator driven by a relativistic electron beam
- Harry Diamond Laboratories, 2800 Powder Mill Rd., Adelphi, Maryland 20783-1145 (US)
- Sandia National Laboratories, Microwave Physics Division, Albuquerque, New Mexico 87185
High-power microwaves (20--50 MW, 8.8 GHz) have been produced in repetitive pulses at a rate of 10 Hz in a joint experiment by Harry Diamond Laboratories and Sandia National Laboratories. These microwaves were produced with Harry Diamond Laboratories' backward-wave oscillator (BWO), driven by a 600 to 800-kV, 2-kA electron beam, which was guided by a magnetic field of variable strength from 0.75 to 1.05 T. The beam was produced with Sandia National Laboratories' repetitive high-voltage pulser, RAVEN. Microwave diagnostic instrumentation included a directional coupler, heterodyne receiver, dispersive waveguide delay line, and calorimeter. In a train of 10 pulses, the shape, duration, and amplitude of the injection voltage and beam current remained unchanged for each individual pulse. The intensity of the final microwave pulse was 40% of the first pulse, and the final pulse was 80% as long as the first. The basic pulse shape remained unchanged. More intense microwave radiation should be obtained with a higher magnetic field. Computer simulations using the code magic predicted the characteristic dip in the magnetic field strength versus microwave power output curve. Code predictions of microwave power output with a warm beam agree very well with experimental results. Finally, cyclotron resonance is presented in a descriptive fashion to account for the power output dip. This is the first experiment with a repetitively pulsed high-power BWO driven by a relativistic electron beam performed outside the USSR.
- OSTI ID:
- 5332419
- Journal Information:
- Journal of Applied Physics; (USA), Vol. 66:8, Issue 8; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
Similar Records
Mode competition in a high current, high voltage gyro-BWO experiment
Mode competition in a high current, high voltage Gyro-BWO experiment
Related Subjects
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BACKWARD WAVE TUBES
ELECTRON BEAMS
MICROWAVE RADIATION
RADIATION SOURCES
COMPUTERIZED SIMULATION
CYCLOTRON RESONANCE
GHZ RANGE 01-100
HZ RANGE
MAGNETIC FIELDS
OSCILLATORS
POWER RANGE 10-100 MW
PULSES
RELATIVISTIC RANGE
BEAMS
ELECTROMAGNETIC RADIATION
ELECTRON TUBES
ELECTRONIC EQUIPMENT
ENERGY RANGE
EQUIPMENT
FREQUENCY RANGE
GHZ RANGE
LEPTON BEAMS
MEGAWATT POWER RANGE
MICROWAVE EQUIPMENT
MICROWAVE TUBES
PARTICLE BEAMS
POWER RANGE
RADIATIONS
RESONANCE
SIMULATION
654001* - Radiation & Shielding Physics- Radiation Physics
Shielding Calculations & Experiments
640301 - Atomic
Molecular & Chemical Physics- Beams & their Reactions