Induction-linac based free-electron laser amplifier for fusion applications

Conference · Mon Aug 01 04:00:00 EDT 1988

OSTI ID:6736768

Jong, R A; Stone, R R

We describe an induction-linac based free-electron laser amplifier design for producing multi-megawatt levels of microwave power for electron cyclotron resonance heating of tokamak fusion devices such as the Compact Ignition Tokamak or the International Thermonuclear Experimental Reactor. The wiggler design strategy incorporates a tapering algorithm suitable for FEL systems with moderate space charge effects and minimizes spontaneous noise growth at frequencies below the fundamental, while enhancing the growth of the signal at the fundamental. In addition, engineering design considerations of the waveguide dimensions, the wiggler magnet gap spacing, the wiggler period, and the minimum magnetic field strength in the tapered region of the wiggler. This FEL is designed to produce an average power of about 10 MW at frequencies in the range from 380 GHz to 560 GHz. The achievement of this average power at a reasonable cost requires a high duty factor, which affects some component design. In addition, the desire to obtain a high extraction efficiency pushes the beam energy up and requires magnetic field strengths in the wiggler that are near or possibly larger than the Halbach limit. We used a methodology for our system study that had been developed earlier. We considered several FEL configurations and selected one that minimized total cost. We determined that increasing the beam energy requires that the wiggler use vanadium-permendur as the pole material. We discuss the basic design of the selected configuration and give the expected performance. 19 refs., 9 figs., 2 tabs.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6736768
• Report Number(s): UCRL-98675; CONF-8808146-2; ON: DE89001923
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101* -- Fusion Energy-- Plasma Research-- Confinement
Heating
& Production
CLOSED PLASMA DEVICES
DESIGN
ECR HEATING
ELECTRICAL EQUIPMENT
ELECTROMAGNETS
EQUIPMENT
FREE ELECTRON LASERS
HEATING
HIGH-FREQUENCY HEATING
LASERS
MAGNETS
PERFORMANCE
PLASMA HEATING
SPACE CHARGE
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
USES
WIGGLER MAGNETS