Thermal camera installation on NI TCS bench and alignment checks

Task performed by Campagna, Canuel, Marque, see Virgo logbook entry #23340

As the ring seems to change in time (at least with the temperature of the laser), we decided to install the thermal camera on the NI bench as well (all optics, hardware and software was ready).
After the installation, the images are reported in the first plot.
Then, we imaged the ring on a screen after the last lens of the setup. And we realigned the setup in order to obtain a nice balanced ring with the 2 mirrors before axicon.
The final images are reported in second plot.
We checked also the ring on the WI bench. It was OK and we did not realigned the setup.
Conclusion:
- The thermal camera images can be used to monitor any change in the ring.
- The last images can be used as reference ones.
- The images on the thermal cameras are not symmetric when the ring on the input mirrors are symmetric. It seems to be due to a problem in the setup used to pick up the thermal camera beam (same defects on both benches). Probably due the splitter used to pick up the beam in a very divergent point. Indeed the asymmetry is in the horizontal plane (the images are rotated by 90 degrees by the software). This problem might disappear when the final setup will be implemented (the splitter of the central spot is temporary used right now).