U.S. National ICH project: results of development, simulation, and testing of antennas for the next large U.S. fusion devices

The National ICH (NICH) Project was established by the U.S. Department of Energy in September 1983 to carry out the needed research and development for high-power, long-pulse ICH launchers and rf systemsas appropriate for DIII-D, TFTR, and TFCX. A description of the development activities of analytical, computer simulation, and experimental investigations of the launcher concepts under development is provided. The computer simulations used to guide the selection of variations on launcher concepts include algorithms that perform the following: (a) solve the Laplace equation εdel/sup 2/phi = 0 in 2-D with dielectrics present in arbitrary geometry and composition, (b) solve the scalar homogeneous Helmholtz equation (del/sup 2/ + ω/sup 2/) phi = 0 in 2-D geometry, (c) solve the complex inhomogeneous vector Helmholtz equations in vacuum (del/sup 2/ + ω/sup 2/)E-vector = iωJ-vector in 3-D, and (d) solve the case of (c) with dielectric plasma (del/sup 2/ = ω/sup 2/ε)E-vector = iωJ-vector. Several different feedthroughs are examined, and different 3-D launchers are examined, including cavity-backed loops and ridge waveguide antennas