Sheila, Kiwamu

 We went to the PSL room today to look for any sign of the beam distortion which we saw yesterday on ISCT1 [1].
However there was no obvious sign of the distortion in the PSL.
We are planning to look at the beam around the light pipe by removing it once we transition to laser hazard.

 We brought a Thorlab beam scan to check the shape of the beam in the downstream after the ALS Faraday. We checked the beam shape at various points : (1) right after the first lens behind the Faraday, (2)  before the first steering mirror (~30 cm afar from the 1st lens), (3) right after the lower periscope mirror and (4) right before it enters the penetration hole. None of them showed any obvious sign and they looked quite "Gaussian" copmared with the software fitting curve on them. Probably it is unlikely that the source of the distortion is in the PSL side.

[1] LHO alog 6050 " ISCT1 work"