Accession Number : ADA139900

Title :   Radiation Growth in a Millimeter-Wave Free-Electron Laser Operating in the Collective Regime.

Descriptive Note : Memorandum rept.,

Corporate Author : NAVAL RESEARCH LAB WASHINGTON DC

Personal Author(s) : Gold,S H ; Black,W M ; Freund,H P ; Granatstein,V L ; Kinkead,A K

PDF Url : ADA139900

Report Date : 20 Mar 1984

Pagination or Media Count : 40

Abstract : Frequency-resolved measurements of radiation growth have been performed on a millimeter-wave free-electron laser using an intense relativistic electron beam. These measurements have shown large radiation growth rates (approx. 2 dB/cm) over a broad instantaneous bandwidth (66-90 GHz), in good agreement with predictions of theory for operation in the collective regime. Growth narrowing and saturation effects have also been observed. In addition, a large increase in experimental power and efficiency has been observed to result from tapering the strength of the axial magnetic field in the sense that compensates for kinetic energy extraction from the electron beam. Direct calorimetric measurements indicate the production of greater than or equal to 75 MW centered at 75 GHz with 6% experimental efficiency. (Author)

Descriptors :   *Electrical lasers, *Free electrons, *Tunable lasers, *Electron beams, *Relativity theory, Millimeter waves, Nonlinear systems, Barometric pressure, Kinetic energy, V band, Magnetic fields, Growth(General), Calorimeters, Predictions, Production, Measurement, Mirrors, Rates, Saturation, Theory, Extraction, Radiation, Air, Intensity, Axes, Lasers

Subject Categories : Lasers and Masers
      Particle Accelerators
      Quantum Theory and Relativity

Distribution Statement : APPROVED FOR PUBLIC RELEASE