  The first neutral beam injection (NBI) experiments in Wendelstein 7-X (W7-X)
stellarator were conducted in the summer of 2018. The NBI system is used to
heat the magnetically confined plasma by neutralising an accelerated hydrogen
ion beam and directing it into the plasma, where the resulting energetic ions
release their energy to heat the plasma. The modelling of the NBI fast ion
experiments has commenced, including estimation of the shine-through and the
orbit-losses. The stellarator has a wide-angle infra red (IR) imaging system to
monitor the machine plasma facing component surface temperatures. This work
validates the NBI model "Beamlet Based NBI (BBNBI)" and the newly written
synthetic IR camera model. The validation is accomplished by comparing the
measured and the synthetic IR camera measurements of an experiment where the
NBI was injected into the vacuum vessel without a plasma. A good qualitative
and quantitative match was found. This agreement is further supported by
spectroscopic and calibration measurements of the NBI and and IR camera
systems.
