In the JET tokamak, ICRF driven fusion reactivity has been determined using measurements of 16.6 MeV γ-ray emission from d[3He, γ]5Li reactions during central RF heating in the (3He)d minority regime. Up to 1 MJ of fast minority ions in the plasma has been produced with the application of up to 15 MW of RF power. The maximum rate produced by d[3He, p]4He fusion reactions has been estimated as 2 × 10l6 s−1 (equivalent to 60 kW of fusion power in charged particle products). The reactivity increased strongly with coupled RF heating power (proportional to (PRF)5/3), with some evidence of a weakening of the dependence leading to a saturation in the energy gain Q at the highest coupled RF power levels (PRF > 8−12 MW). The experimentally measured anisotropic fast ion energies and fusion reaction rates have been simulated using a radially dependent Stix model for a wide variety of discharges. Analysis of the radial profile of fusion reactivity shows that when the RF power density is maximized on the magnetic axis of the discharge, the fusion reactivity is peaked away from the axis. This effect is caused by the minority ions near the centre of the discharge being driven to energies beyond the maximum in the fusion cross-section.

The evolution of the density profile in PLT during intense gas puffing is documented and analyzed.Measurements of the spectrum of low energy edge 10 cm/s. These transport coefficients are 10 + 10 times larger than neoclassical. The ion energy confinement is reduced, the small scale density fluctuations are increased, and runaway electrons losses are increased during the density rise.(1) Los alamos National Laboratory CTP.-S Ms-302 Lo» Alamos, NM 87545(2)

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A code has been developed which calculates the cyclotron radiation spectrum emitted by a slab model tokamak plasma in a direction outward along a major radius. The calculation assumes both a thermal and a suprathermal electron component for the plasma, and includes the effects of self-absorption of the radiation by the thermal plasma. Various methods are described by which the cyclotron radiation spectrum can be unfolded to obtain parameters of the electron population. A procedure is described by which the electron temperature profile can be obtained from spectral measurements of the cyclotron emission at optically thin frequencies. No absolute calibration of the detection equipment is needed for this method. The code can be used to find parameters of the suprathermal distribution function from its synchrotron emission spectrum, and for the special case of suprathermal electrons at a constant major radius, analytical results are obtained. Finally, the code has been used to calculate cyclotron spectra for various tokamaks: CLEO, TFR, ATC, PLT, and Alcator.