The Electric Tokamak, a low field ITER sized device with R = 5 m, has been operating with well equilibrated clean plasmas since January 2000. Short, 0.9 s, discharges with a central energy confinement time τE(0) = 150 ms are now routinely obtained at a toroidal field B = 0.1 T with kTe, kTi≃120 eV. The discharges are feedback controlled in up/down position and in plasma current. Biased electrode driven H modes have been obtained that compare well with the results obtained on CCT by R.J. Taylor and align with the `neoclassical bifurcation' theory of K.C. Shaing. Very successful second harmonic ion heating has been demonstrated with the ICRF antenna outside the vacuum system and with 50% single pass absorption. ICRF heated discharges indicate that poloidal rotation sufficient for edge bifurcation (H mode) may soon be achieved by ICRF induced fast ion losses. The threshold electrode biasing current required for bifurcated poloidal rotation has so far been reduced by 70% owing to ICRH driven ion orbit loss. The remaining critical ICRF item needed for the exploration of high beta plasma equilibria is the demonstration of the required current profile shaping. It is expected that mode conversion in the ion-ion hybrid regime, with high field side launch, will allow the current drive required to approach and exceed the Troyon beta limit. In 1-D full wave calculations, high harmonic current drive appears most promising at higher beta. Achieving the goal of plasma equilibration near unity beta will require 10 s long discharges (at kT = 3 keV, ne = 3×1019 m-3, B = 0.25 T) because of current profile shaping requirements.

A dominant particle pinch is observed in Ohmic plasmas of the electric tokamak (ET) associated with enhanced poloidal rotation. The density increases dramatically, with strong profile peaking. In pinch dominated particle transport, the pinch velocity profile is determined from the Thomson density profile data. The pinching rate is controlled with soft gas puffing. Hard puffing produces inverted density profiles that do not pinch due to the MHD instabilities. The build-up time of the density is typically 1 s. Due to density accumulation in the absence of significant core fuelling, the characteristic Troyon limit (βN = βaB/I ∼ 3,%, m, T, MA) is reached even in Ohmic plasmas. Density ramps are terminated by internal disruptions due to beta collapse without any significant radiative energy loss. The loop voltage remains low (0.4 V) during the ramp. Prior to, and during the ramp, we observe no reduction in the electrostatic fluctuations in the present experiments. Electrode biasing, using the J × B force, shows that the density accumulation can be reduced and even stopped through slowing the poloidal rotation (reducing the magnitude of the background negative Er). This observation is consistent with the presence of a ‘viscous’ pinch driven by the dominance of the radial electric field through ion mobility. Other neoclassical pinch mechanisms (i.e. Ware and thermoelectric) contribute to the density accumulation and are shown to be secondary effects as revealed by the radial current modulation effects. The easily achieved thermal Mach numbers are ±0.15 for poloidal and ±0.2 for toroidal rotation using the present biaser. There is no significant spontaneous toroidal rotation. The spontaneous poloidal rotation seen in Ohmic plasmas has the thermal Mach number Mp ∼ 0.15 across the measured profile where r/a > 0.5. This rotation is sufficient to account for the observed radial pinch velocity.

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Using experimental and numerical simulation analysis the breakdown voltage walkout effect has been studied in 40 V ESD protection devices based on extended drain MOS devices implemented in a 5 V CMOS process. A similar effect has been observed in 100 V and 24 V BiCMOS processes. The physical mechanism of this effect is revealed as the result of hot electron capture in the thick field oxide of the extended drain region. To address this, a method to reduce the walkout effect in high voltage ESD devices is proposed and experimentally validated.