Introduction of Neutron Collimation signals to FIDASIM

FIDASIM[1] is a synthetic diagnostic code that simulates multiple fast-ion diagnostics, including fast ion D-alpha (FIDA), neutral particle analyzer (NPA), and charged fusion products (CFPD)[2]. FIDASIM takes plasma parameters in 2D or 3D as well as a fast-ion distribution function to produce synthetic diagnostic data. In this work, FIDASIM is extended to simulate neutron collimation diagnostics by tracking fusion product neutrons through detector geometry. Simulated neutron spectra are compared with experimental neutron spectra produced on MAST-U [3] and on LHD [4][5] demonstrating usefulness both in 2D and 3D geometries. Simulated spectra show qualitative agreement with experimental results, further validating the extensibility of FIDASIM as a synthetic diagnostic code.

[1] B. Geiger, et al 2020 Plasma Phy. Control. Fusion 62 105008

[2] W W Heidbrink et al 2021 Plasma Phy. Control. Fusion 63 055008

[3] M Cecconello et al 2023 Plasma Phy. Control. Fusion 65 035013

[4] K Ogawa et al 2018 Rev. Sci. Instrum. 89 113509

[5] M. Isobe et al 2018 Nucl. Fusion 58 082004