1 MeV Triton Orbit Analysis in EAST Plasmas

Abstract

A fusion burning plasma is sustained by deuterium-tritium (DT)-born energetic alpha particles. Therefore, energetic alpha particles must be well confined. In a deuterium experiment, 1 MeV tritons are created by D(d,p)T reactions. 1 MeV triton is regarded as simulated DT-born alpha particles because their kinetic parameters are almost same. A study of 1 MeV triton confinement has been widely and intensively performed in fusion devices in order to understand alpha particle confinement. To understand 1 MeV triton confinement/loss in EAST plasmas, 1 MeV triton orbit analysis is performed in various plasma current (I_p) cases using LORBIT codes. It is shown that the number of lost tritons decreases with an increase in I_p. The number of lost tritons rapidly increases at 10⁻⁶ s; then, it is almost saturated at 10⁻⁵ s regardless of I_p. The pitch angle distribution of confined 1 MeV triton shows that tritons that exist in a wider pitch angle range can be confined in the higher I_p case compared with the lower I_p case.