Using E-beam Mapping to Detect Coil Misalignment in NCSX

Following assembly of the NCSX device, a program of e-beam mapping experiments is planned to validate the accuracy of the construction and assembly of the NCSX coil systems. To aid in the development of requirements for the e-beam mapping hardware and machine requirements, simulations of the e-beam mapping experiments, including various coil misalignments, have been done. The magnetic flux surface configuration was constructed using a numerical code, based on the Biot-Savart law, to calculate the magnetic field components and trace the field line trajectory many times around the torus. Magnetic surfaces are then mapped by recording the field line intersections with toroidal cross-sections of the magnetic system, much as in an actual e-beam mapping experiment

The diffusion of fast ions in Ohmic TFTR discharges

Short duration (20 msec) neutral deuterium beams are injected into the TFTR tokamak [Plasma Physics and Controlled Nuclear Fusion Research 1986 (IAEA, Vienna, 1987), Vol. I, p. 51]. The subsequent confinement, thermalization, and diffusion of the beam ions are studied with multichannel neutron and charge exchange diagnostics. The central fast-ion diffusion (<0.05 m /sec) is an order of magnitude smaller than typical thermal transport coefficients. © 1991 American Institute of Physics.

Comparison of steady-state and perturbative transport coefficients in TFTR

Steady-state and perturbative transport analysis are complementary techniques for the study of transport in tokamaks. These techniques are applied to the investigation of auxiliary-heated L-mode and supershot plasmas in the tokamak fusion test reactor (TFTR) [R. J. Hawryluk et al., Plasma Physics and Controlled Nuclear Fusion Research, Proceedings of the 11th International Conference, Kyoto, 1986 (IAEA, Vienna, 1987), Vol. 1, p. 51.]. In the L mode, both steady-state and perturbative transport measurements reveal a strong temperature dependence that is consistent with electrostatic microinstability theory and the degradation of confinement with neutral beam power. Steady-state analysis of the ion heat and momentum balance in supershots indicates a reduction and a significant weakening of the power-law dependence on the transport in the center of the discharge. © 1991 American Institute of Physics

Comparison of steady-state and perturbative transport coefficients in TFTR

Steady-state and perturbative transport analysis are complementary techniques for the study of transport in tokamaks. These techniques are applied to the investigation of auxiliary-heated L-mode and supershot plasmas in the tokamak fusion test reactor (TFTR) [R. J. Hawryluk et al., Plasma Physics and Controlled Nuclear Fusion Research, Proceedings of the 11th International Conference, Kyoto, 1986 (IAEA, Vienna, 1987), Vol. 1, p. 51.]. In the L mode, both steady-state and perturbative transport measurements reveal a strong temperature dependence that is consistent with electrostatic microinstability theory and the degradation of confinement with neutral beam power. Steady-state analysis of the ion heat and momentum balance in supershots indicates a reduction and a significant weakening of the power-law dependence on the transport in the center of the discharge. © 1991 American Institute of Physics

Alpha particle losses from Tokamak Fusion Test Reactor deuterium–tritium plasmas

Because alpha particle losses can have a significant influence on tokamak reactor viability, the loss of deuterium–tritium alpha particles from the Tokamak Fusion Test Reactor (TFTR) [K. M. McGuire et al., Phys. Plasmas 2, 2176 (1995)] has been measured under a wide range of conditions. In TFTR, first orbit loss and stochastic toroidal field ripple diffusion are always present. Other losses can arise due to magnetohydrodynamic instabilities or due to waves in the ion cyclotron range of frequencies. No alpha particle losses have yet been seen due to collective instabilities driven by alphas. Ion Bernstein waves can drive large losses of fast ions from TFTR, and details of those losses support one element of the alpha energy channeling scenario. © 1996, American Institute of Physics. All rights reserved

Alpha particle losses from Tokamak Fusion Test Reactor deuterium–tritium plasmas

Because alpha particle losses can have a significant influence on tokamak reactor viability, the loss of deuterium–tritium alpha particles from the Tokamak Fusion Test Reactor (TFTR) [K. M. McGuire et al., Phys. Plasmas 2, 2176 (1995)] has been measured under a wide range of conditions. In TFTR, first orbit loss and stochastic toroidal field ripple diffusion are always present. Other losses can arise due to magnetohydrodynamic instabilities or due to waves in the ion cyclotron range of frequencies. No alpha particle losses have yet been seen due to collective instabilities driven by alphas. Ion Bernstein waves can drive large losses of fast ions from TFTR, and details of those losses support one element of the alpha energy channeling scenario. © 1996, American Institute of Physics. All rights reserved

Acceleration of beam ions during major-radius compression in the tokamak fusion test reactor.

Tangentially coinjected deuterium beam ions were accelerated from 82 up to 150 keV during a major-radius compression experiment in the tokamak fusion test reactor. The ion energy spectra and the variation in fusion yield were in good agreement with Fokker-Planck code simulations. In addition, the plasma rotation velocity was observed to rise during compression. © 1985 The American Physical Society

Acceleration of beam ions during major-radius compression in the tokamak fusion test reactor.

Tangentially coinjected deuterium beam ions were accelerated from 82 up to 150 keV during a major-radius compression experiment in the tokamak fusion test reactor. The ion energy spectra and the variation in fusion yield were in good agreement with Fokker-Planck code simulations. In addition, the plasma rotation velocity was observed to rise during compression. © 1985 The American Physical Society

High-temperature plasmas in a tokamak fusion test reactor.

Neutral-beam heating of plasmas in the Tokamak Fusion Test Reactor at low preinjection densities [ne(0)1019 m-3] were characterized by Te(0)=6.5 keV, Ti(0)=20 keV, ne(0)=7×1019 m-3, E=170 msec, theta=2, and a d(d,n)3He neutron emission rate of 1016 sec-1. The ion temperature and the deuterium-fusion neutron yields were significantly higher than for previous tokamak experiments. The low initial densities were achieved by operation of the Tokamak Fusion Test Reactor with low plasma currents (1 MA) and by extensive limiter conditioning. © 1987 The American Physical Society