Fast ion physics with NBI on WHAM*

WHAM is an axisymmetric magnetic mirror experiment that aims to demonstrate the viability of the magnetic mirror approach to fusion.

Neutral beam heating will be used to produce a large population of fast ions that boost the fusion reactivity and provide kinetic stability. 

We present the first experimental results from the WHAM experiment with NBI, modelling and diagnostics updates. 

NBI performance is characterized by the full energy fraction measured via doppler shift spectroscopy and beam divergence measured via a shine-thru array.

CQL3D, a bounce averaged Fokker-Planck equation solver used to model the ion population evolution in WHAM with measured NBI parameters, is used to study the effect of density and temperature profiles on the fast ion population.

Modelling predictions of the spatial localization of the fast ions will be compared to measurements from an axial proton detector array, total fusion reactivity with a neutron detector, and the fast ion confinement time from flux loops.

This comparison will help validate computer modelling and give more confidence in modelling predictions of a future mirror reactor.