Experimental Study of Triton Burnup in EAST Using Neutron Activation Method

A neutron activation system with two sets of activation terminals was developed in the experimental advanced superconducting tokamak (EAST), and it was implemented in the measurements of the time-integrated triton burnup for the deuterium plasma experiment in EAST. Indium and silicon samples with an energy threshold of 0.3 and 4.0 MeV were used to measure the DD and DT neutron, respectively. The shot-averaged triton burnup ratio was determined by simultaneously measuring the DD and DT neutron yields during plasma discharges. The triton burnup ratio of EAST was found to range from 0.035% to 0.65%, depending on plasma parameters. Due to a better confinement of fast triton, the triton burnup ratio increases with the plasma current and the magnetic field in the range of 400–600 kA and 1.74–2.57 T, respectively. Additionally, the triton burnup ratio initially increased and then decreased with electron density in the range of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3.8\times 10^{19}$</tex-math> </inline-formula>–<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$6.0\times 10^{19}$</tex-math> </inline-formula> m<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−3</sup>, with a turning point observed at approximately <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4.4\times 10^{19}$</tex-math> </inline-formula> m<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−3</sup>.