Prediction of neutron emission rate in deuterium neutral beam heated CFQS plasmas using FIT3D-DD code

FIT3D-DD code, which is a neutron emission and heating efficiency evaluation code based on a simple analytical solution of the Fokker-Planck equation, was applied to deuterium Chinese first quasi-axisymmetric stellarator (CFQS) plasmas heated by a deuterium neutral beam injector. A database of the neutron emission rate due to the beam-bulk D-D fusion reaction in the CFQS was created with the electron temperature and density, which were evaluated from the energy confinement time using ISS04 scaling. The neutron emission rate increases monotonically with the increase in the electron temperature and density. The neutron emission rate is expected to be up to ∼2.7 × 10¹² [n/s] for an electron density of less than 4 × 10¹⁹ m⁻³. (author)