Scaling Calculations for a Relativistic Gyrotron.
Abstract
The relativistic gyrotron is under development as an ultra-high power source of millimeter wave radiation. The purpose of the present study is to estimate the optimum operating characteristics of gyrotrons based on multi-kiloampere, mega-electron volt electron beams. Gyrotrons with weakly relativistic, moderate current electron beams have demonstrated very high efficiency and average power at millimeter wavelengths and the possibility of achieving good efficiencies at very high peak powers is of interest. Compared to other high power millimeter wave generators, gyrotrons are relatively insensitive to electron beam velocity spread and thus appear well suited to device configurations based on high current pulseline accelerators. The results of this study indicate that the relativistic gyrotron has potential for achieving high efficiency (15-30%) using relativistic electron beams with gamma approx 2-3. Optimum efficiency occurs for short interaction lengths; characterized by 4-8 cyclotron periods. Such short interaction lengths lead to the possibility of very high peak power generation using multi-kiloampere beams: 100-300 MW with a 600 ke V beam and about 1 GW with a 1 Me V beam. The output power risetime has been estimated to be a few nanoseconds for a low Q oscillator at 35 GHz which implies the gyrotron interaction can be readily investigated using a 20-100 nsec pulseline accelerator. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 31, 1985
- Accession Number
- ADA157476
Entities
People
- Arne W. Fliflet
Organizations
- United States Naval Research Laboratory