We performed the Finesse measurement Xarm.
1. HWP vs IMC trans power relationship
We checked the relationship between PSL HWP and IMC trans power.
Fig.1. showed the result.
Detail would be reported by Dan-san.
2. Hand initial alignment.
When we perform IR lock, the transmittance power of TMSX IR PD was about 0.5.
And GRX flash was very weak.
Fig.2. showed the status of GRX
After performing the hand on alignment for PR3, ITMX and ETMX, the IR trans power became 0.8.
3. Finesse measurement
When I started the script of finesse measurement, IR lock loss always happened when PSL HWP changed from 15 to 16.
So I changed the target HWP value from 20 to 15
DATE : 2024/05/20 22:59 UTC
ARM : X
TEMP ITM : 296.8
TEMP ETM : 296.3
NUM : 10
IFO REFL HWP : 146.0
PSL HWP : 15.0
IMC POWER : 3.9
VALUE : 1475.3
ERROR : 16.5
Measured data is stored to /users/Commissioning/data/Finesse/Xarm/20240520-2259\
00
HWP vs IMC trans power relationship
| HWP [degree] | IMC trans [W] |
| 7 | 1.45 |
| 8 | 1.72 |
| 9 | 2.0 |
| 10 | 2.3 |
| 11 | 2.6 |
| 12 | 2.9 |
| 13 | 3.25 |
| 14 | 3.6 |
| 15 | 3.9 |
| 16 | 4.25 |
| 17 | 4.65 |
| 18 | 5.0 |
| 19 | 5.3 |
| 20 | 5.7 |