[Uchiyama, Ushiba]

We inserted 2-inch BS (NPPH(+/-5%)Q-50.8C08-20-W0.5D-1064) between RBS1 and RBS3 TMSY as shown in fig1 (yellow square).
The ghost beam generated by BS was caught by existing beam dump, which dumps surface reflection of RPD2 (see also fig1).
Figure 2 shows the photos, and BS and beam dump are shown by yellow and blue arrows, respectively.

After that, we centered GR/IR QPDs, and PDs including S/P-pol monitors.
I also added a gain of 2 at FM1 of K1:TM-Y_IR_PDA1 to compensate the power reduction.
Michimura-san and Yokozawa-san performed the similar work at TMSX (32183).

After the work on TMSX/Y, we confirmed PRFPMI can be locked with RF signals, so the work doesn't affect to the lock acquisition.