The complete ion cyclotron range of frequency (ICRF) heating system for the Tokamak Fusion Test Reactor (TFTR), consisting of four antennas and six generators designed to deliver 12.5 MW to the TFTR plasma, has now been installed. Recently a series of experiments has been conducted to explore the effect of ICRF heating on the performance of low recycling, Supershot plasmas in minority and non-resonant electron heating regimes. The addition of up to 7.4 MW of ICRF power to full size (R ∼ 2.6 m, a ∼ 0.95 m), helium-3 minority, deuterium Supershots heated with up to 30 MW of deuterium neutral beam injection has resulted in a significant increase in core electron temperature (?T{sub e}=3--4 key). Simulations of equivalent deuterium-tritium (D-T) Supershots predict that such ICRF heating should result in an increase in ?{sub alpha}(O) ∼ 30%. Direct electron heating has been observed and has been found to be in agreement with theory. ICRF heating has also been coupled to neutral beam heated plasmas fueled by frozen deuterium pellets. In addition ICRF heated energetic ion tails have been used to simulate fusion alpha particles in high recycling plasmas. Up to 11.4 MW of ICRF heating has been coupled into a hydrogen minority, high recycling helium plasma and the first observation of the toroidal Alfven eigenmode (TAE) instability driven by the energetic proton tail has been made in this regime.

Ion cyclotron heating (ICH) has been chosen as the primary method for providing auxiliary heating power to the plasma in the Compact Ignition Tokamak (CIT). Sustained progress in ion cyclotron range of frequencies (ICRF) heating experiments, together with supporting technology development, continues to justify selection of this technique as the preferred one for heating CIT to ignition. However, the CIT requirements are sufficiently different from existing achievements that continued experimentation and development are needed to meet the goals of the CIT experiment with a high degree of reliability. The purpose of this report is fourfold: (1) to review briefly the physics and technology research and development (R and D) needs for ICH on CIT, (2) to review the status of and planned programs for ICH on US and international machines, (3) to propose a unified ''mainline'' R and D program specifically geared to testing components for CIT, and (4) to assess the needs for experiments including C-Mod, the Tokamak Fusion Test Reactor (TFTR), and DIII-D to provide earlier information and improved probability of success for CIT ICH. 4 refs., 4 figs., 5 tabs.

Localized direct electron heating by mode-converted ion cyclotron range of frequencies (ICRF) waves in D(H) tokamak plasmas has been clearly observed for the first time in Alcator C-Mod. Both on- and off-axis (high field side) mode conversion electron heating (MCEH) have been observed. The MCEH profile was obtained from a break in slope analysis of electron temperature signals in the presence of rf (radio frequency) shut-off. The temperature was measured by a 32-channel high spatial resolution (7 mm) 2nd harmonic heterodyne electron cyclotron emission (ECE) system. The experimental profiles were compared with the predictions from a toroidal full-wave ICRF code TORIC. Using the hydrogen concentration measured by a high-resolution optical spectrometer, TORIC predictions were shown qualitatively in agreement with the experimental results for both on- and off-axis MC cases. From the simulations, the electron heating from mode converted ion cyclotron wave (ICW) and ion Bernstein wave (IBW) is examined.