Accession Number:

ADA247060

Title:

Intense Electron Beam Cyclotron Masers with Microsecond Pulselengths

Descriptive Note:

Final rept. 1 Aug 1988-30 Nov 1991

Corporate Author:

MICHIGAN UNIV ANN ARBOR INTENSE ENERGY BEAM INTERACTION LAB

Personal Author(s):

• Gilgenbach, Ronald M.

Report Date:

1991-12-20

Pagination or Media Count:

91.0

Abstract:

Results are reported for a three year research program with the goal of generating high power microwaves over long-pulselengths. Three types of cyclotron maser devices were developed and utilized in experiments on the Michigan Electron Long Beam Accelerator, MELBA at electron beam parameters of 0.6-0.9 MV, 0.52-2 kA, and 0.5-5 microsec 1 The gyrotron backward-wave- oscillator, gyro-BWO produced the optimal combination of high power 1-8 MW and long pulse 0.5-1.2 microsec microwave generation. Due to these promising results, this gyro-BWO device was investigated most intensively during the final phase of this research program. 2 Bragg resonator cyclotron resonance masers were investigated with high quality, low current electron beams for high frequency microwave generation. These devices generated hundreds of kW for hundreds of ns, but it was found that microwaves originated from cyclotron harmonic generation on absolute instabilities. 3 Open cavity resonators of unslotted and slotted types generated microwave spikes 20-40 ns in the X-band with peak power up to 15-25 MW. High peak microwave power MW was also generated in the K-band, most likely from the second cyclotron harmonic.

Descriptors:

• *ELECTRON BEAMS
• HIGH POWER
• HIGH FREQUENCY
• PARAMETERS
• MASERS
• RADIOFREQUENCY POWER
• MICHIGAN
• CYCLOTRONS
• HARMONIC GENERATORS
• SPIKES
• CAVITY RESONATORS
• PULSES
• MICROWAVES
• PEAK POWER

Subject Categories:

• Lasers and Masers

Distribution Statement:

APPROVED FOR PUBLIC RELEASE