Tritium Recycling and Transport in TFTR Plasmas with Deuterium Neutral Beam Injection
Authors: R.V. Budny, M. Bitter, H.H. Duong, et al
Tritium recycling rates and transport into the reacting core of TFTR discharges heated with deuterium neutral beam injection are studied. The measured neutron emission rates and the TRANSP plasma analysis code are used. A model for the transport of tritium and deuterium is shown to simulate the DT neutron emission profile shapes in approximate agreement with measurements. The fraction of tritium in the hydrogenic recycling influx through the last closed flux surface is adjusted to fit the magnitude of the measured DT rates. This fraction is approximately 2-4 times the fraction of tritium in the Balmer-alpha line emission. Approximately 150 discharges are studied, including supershots, reversed shear and enhanced reversed shear discharges, H-mode discharges, and L-mode discharges. General scaling relations are given for the central tritium density, tritium recycling fraction, the global DD and DT neutron emission rates, and the tritium effective fueling efficiency at the time of peak DT neutron emission.