Some mirrors are installed on PSL table.

And also  EOMs are replaced, because the PSL layout was changed. The transmittance of each EOMs are as below

EOM1 : 69.8mW/70.7mW = 98.7%

EOM2 : 68.9mW/69.5mW = 99.1%

 

The beam travel roughly 9m after last lens(L9) and measured the beam size around same position as  MC waist. The beam diameter was around 6000um in horizontal and,4000um in vertical and it does not change so much before and after some meter around the MC wais distance.  Target beam is 4700um in diameter at MC waist, so the beam is not so bad mode. We have not had PMC yet. The fine mode match is not necessary at this point. We think it's good enough already.

 

First of all I marked off the input beam line projection to the optical table. That was calculated by the survey at iKAGRA(2015 July). Then we aligned two mirrors before the periscope so as to travel along with that line. We used a laser marker to alignment as the attached picture. The laser marker was set so that the vertical laser is along to that beam line and the height is same as the target seal attached yesterday. 

Then the beam went out through the MCF REFL viewport to MC REFL optical table and after small alignment of periscope mirrors, the beam hit almost center of RFQPDs installed at IMC asc test experiment. 

 

 

Concern

The beam hit the viewport between the MCF chamber and the PSL room at the point close to edge of it (it might be some cm from edge). We didn't care where hit at viewport on iKAGR operation, so possibly it hit close to edge also on iKAGRA operation.