Ion temperatures of reversed field pinch plasmas in TPE-1 R(M) from D sub(α) line Doppler broadening

Ion temperatures of Reversed Field Pinch (RFP) plasmas in TPE-1R (M) have been deduced from the spectrum wing of Doppler-broadening Deuterium Balmer α line (D sub(α) line). Maximum deuterium temperature of 75eV, which is considered to be average ion temperature, is obtained at the plasma current of 120kA. Deuterium temperatures at 0.6 msec are roughly proportional to the plasma currents. Assuming that the heating mechanism of ions is only due to the Coulomb collision with electrons, ion energy confinement time of 2.3 msec is obtained at the plasma current of 85kA, which is about two-thirds of the time determined by the classical ion conduction loss. The scaling of the ion energy confinement time on the plasma current is roughly obtained to be Isub(p)sup(3/2), which is the same as that of the electron energy confinement time in TPE-1R (M) plasmas. (author)