Speaker
Description
Neutron and gamma-ray diagnostics will play a fundamental role in fast-ion detection in burning fusion plasmas. As the fast ion undergoes a fusion reaction, the generated neutron or gamma-ray will carry away some of its energy, which can be detected. In the context of axisymmetric machines with high aspect ratio, it is possible to represent the fast-ion phase space in the reduced three-dimensional orbit space, combining position and velocity. In this work, we show the link between position space and fast-ion orbit space for two different choices of coordinates, i.e. the energy, maximum major radius and pitch at maximum major radius ($E$,$R_m$,$p_m$) and the energy, magnetic moment and toroidal canonical angular momentum ($E$,$\mu$,$P_\phi$). We do so by calculating the sensitivity of hypothetical diagnostics in the magnetic equilibrium of ITER for a set of different line-of-sight geometries. This information is encoded in the so-called orbit-space weight functions.
