Slow wave wigglers for compact free electron lasers

Journal Article · Fri Sep 01 04:00:00 EDT 1995 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.871133· OSTI ID:172188

Riyopoulos, S ^[1]

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1. Science Application International Corporation, McLean, Virginia 22102 (United States)

The use of slow waves excited in magnetron-type cavities as wigglers for compact free electron lasers (FEL) is analyzed. Because of group velocities much below the speed of light, slow waves offer an order of magnitude increase in FEL gain under given circulating power in the wiggler resonator, compared to fast wave wigglers of a similar period. In addition, the radiation emission involves the relativistic upshifting of the spatial harmonics of the wiggler period. That offers the versatility of operation, either at high beam energy, via upshifting of the fundamental wavelength, or at low beam energy, benefiting from the submillimeter wiggler harmonics. Because the main electron undulation is in the transverse direction for all spatial harmonics, the radiated power is increased by a factor {gamma}{sup 2} relative to the Smith--Purcell approach that relies on axial electron undulation. Technical advantages offered by magnetron-type wiggles are the generation of the wiggler microwaves and the FEL interaction take place inside the same cavity, avoiding the issue of high-power coupling between cavities; the excitation of wiggler microwaves relies on distributed electron emission from the cavity wall and does not require separate beam injection. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

• OSTI ID: 172188
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 9 Vol. 2; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
ELECTRON BEAMS
ELECTRON TUBES
FREE ELECTRON LASERS
MAGNETRONS
MICROWAVE RADIATION
RELATIVISTIC RANGE
WAVEGUIDES
WIGGLER MAGNETS