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, τE=170 msec, βₜₕₑₜₐ=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.