[Ohishi, Sugawara, Michimura]

We placed and aligned bKAGRA IMMT1 using the interferometer beam.
Now the beam hits bKAGRA IMMT1 at the center and iKAGRA IMMT2 at the center.

What we did:
1. Placed the bKAGRA IMMT1 (mirror locked, first contact on HR surface removed, FC still on AR surface) to the place roughly where iKAGRA IMMT1 was, and tuned the position so that the beam hits IMMT1 at the center.

2. To do so, we had to remove iKAGRA IMMT1 and the beam dump behind IMMT1 (the one used to dump IMMT1 trasmitted IFO REFL beam). We couldn't remove iKAGRA IMMT1 completely outside the chamber since picomotor cabling was pretty tight.

3. Aligned bKAGRA IMMT1 in yaw by rotating the suspension frame, in pitch by adjusting the earthquake stops, to center the beam on iKAGRA IMMT2.

4. Iterate 1 and 3 to get the beam both centered on bKAGRA IMMT1 and iKAGRA IMMT2.

5. Using some spare time, we removed things on iKAGRA IFO REFL table since it will be replaced to 2400mmx1200mm table on the week of Feb 6.

Result:
1. Photo 1 and Photo 2 show the beam at bKAGRA IMMT1 and iKAGRA IMMT2, respectively. The beam is centered.

2. Photo 3 and Photo 4 show current bKAGRA IMMT1 position with respect to the optical table in IMM chamber.

3. Photo 5 shows current situation in IMM chamber.

Next:
1. Remove the white sheet under the bKAGRA IMMT1 without destroying the alignment

2. Remove iKAGRA IMMT2 and place bKAGRA IMMT2.

3. Measure the beam profile around IMMT1 and IMMT2.

4. Remove iKAGRA IMMT1 and iKAGRA IMMT2 from the chambers.