[Aidan, Thomas, Elli] Following some strange behavior in the Hartmann sensor signals, we checked the layout of the telescope on the ALS table and found that the lenses were out of position. The target and measured distances are show in the following table.
| Distance | Target | Measured |
| F0 to F1 | 614 mm | 675. mm |
| F1 to F2 | 1313 mm | 1232. mm |
| F2 to HWS | 1338 mm | 1530. mm |
We adjusted the positions of the lenses until they matched the target distances.
Separately, I calculated the tolerance of the conjugate plane of the ETM near the HWS to the position of these lenses. The ratio of the displacement of the conjugate plane to variation in the distances between optics is ~14x for F0-to-F1 and ~ 0.02x for F1-to-F2. As such, we placed lens F1 on a translation stage oriented along the optical axis. This will give us fine control over the position of the image plane of the ETM near the HWS.
The beam now looks much more uniform and Gaussian on the HWS. The beam size is 11% smaller than the expected beam size of 1.58mm (see attached plot).
We removed the Hartmann plate from the sensor last night and left a version of the code running that measured the beam position on the CCD. Watching this in real-time we could see the beam wandering around as Keita and Rana swung the TMS telescope around.
