we tried to find the TR GRY signal using the TMSY GR PD and TCams
(Uchiyama-san agreed to use GRY laser in this early morning)
1. Opened the GRY shutter
2. Set SR3 suspension to ALIGNED state
3. Check the image of TCam at IY (Fig.1.)
As you can see, the GR beam spot at IY is relatively higher
4. Changed the TM set value to center the beam spot at IY by my eye
We changed the set value
P : -6 -> 250
Y : 7 -> -50
5. Check the image of TCam at IY again (Fig.2.)
We confirmed the beam spot close to center.
6. Set SR3 suspension to OLDAMP_OFF state
7. Started the oscillation using the awggui(about +/- 20 urad in both P and Y).
But, I cannot find the GRY light at TMSY GR PD in this morning.
(I noticed that SR2 state was SAFE ...)
Different points are
1. Set SR2 suspension to ALIGNED state (with SR3 suspension to ALIGNED state)
Fig.1. SR2 SAFE
Fig.2. SR2 ALIGNED
2. Oscillate the SR3 TM about +/- 100 urad.
But I couldn't find the GRY beam at TMSY GR PD.
Anyway, the TCam image of EYA is too bright compared with other suspensions, I will check it later.
The search region expanded to >300 urad (100 cnt in P and 500 cnt in Y).
For Yaw case, we can scan almost all range of ITMY mirror.
(For P, by adding the offset value to TM stage, we can follow almost all range of ITMY)
Only once, I can find some signal in TMSY GRPD (Fig.1. and Fig.2.)
The TCam image of ITMY can be seen in Fig.3.
TM P : 200.1 [urad]
TM Y : -309.21 [urad]
After finding, I tried to search better alignment around finding angle of SR3, but I cannot find signal after that.
Anyway, length setting of SR3 (or check of GR beam on the SR3 or POS table) would be necessary.
(Or accident scattering light?)
I tweeked the SR3 alignment but could not find the GRY at Yend.
Scan range is probably 500 urad or more for both pitch and yaw (we could not measure the exact angle because of the limitation of the range of OpLevs).
During the measurement, we could clearly see that beam spot on ITMY moves, so scan range shoud be large enough.
It is neccessary to check POS table and GRY beam spot on SR3.