Energy confinement studies in the Phaedrus-T tokamak

Abstract

Summary form only given, as follows. Energy confinement has been studied on the Phaedrus-T Tokamak. The study was performed using (1) a diamagnetic loop to measure the total plasma energy, W, and global energy confinement times, /spl tau//sub E/; (2) Thompson scattering to measure the electron temperature, T/sub e/, and electron density, n/sub e/, profiles; (3) a visible bremsstrahlung diagnostic to determine bremsstrahlung emission profiles and thus the effective ion charge, Z/sub eff/, profiles; (4) pyrobolometers to measure the power leaving the plasma as radiation, P/sub rad/. The profile measurements allowed us to determine not only global confinement times but local electron energy confinement times. The study included data from different tokamak operating modes including ohmic, biased probe induced H-Mode and plasma with RF power at different phasings. How /spl tau//sub E/ scales with several plasma parameters, including line density, n/sub l/, plasma current, I/sub p/, toroidal magnetic field, B/sub T/, and RF power, P/sub rf/, has been studied. The determined plasma scalings are compared to several experimentally and theoretically derived scaling laws. The energy confinement time is also compared to the particle confinement time, /spl tau//sub P/.