CARM signal detection by using 2nd PD 2023/07/24
Participants: Komori, Aso, Miyoki, Ushiba, Uchiyama, Miyakawa, Akutsu, Dan, Oshino, Washimi, YamaT, Takahashi.R, Kanda,
Zoom meeting: https://zoom.us/j/5045179604
Minutes
- 2/7 CARM out of loop measurement.
Old estimation: shotnoise should be below the unknown noise (< kHz).
- For noise budget: If shot noise at in-loop PD1 limits, the shot noise of PD2 has no coherence with shot noise at PD1.
- Analog excitation is necessary for injection. But MOC is connected at this point. So we need cable reconnection. SW can be introduced?
- 3/7 RF PD
- We have several.
- Shunt R should be removed. Tune RF properties.
- 5/7 Reck preparation: OK
- 6/7 Where we should put PD2?: Wide space
- 7/7 Schedule: Aug/21~28 (2 days)
- 2/7 CARM out of loop measurement.
- Opinion:
- How about 3rd PD for the MICH control?
- CARM PD can be used, however, the laser power is minimized for CARM. While MICH requires more power!
Haoyu calculated we could obtain a better S/N signal or not -> Yes!! 10 times better than CARM Q phase signal.
- 2nd PD can be used for this purpose?
- 50mW can be detected by these PDs.
- 10W is necessary.
- Model number will increase. Can we?? Dual IQ can be added in a rack?. Quad IQ can be used for minimization? Whitening one more.
- Let's put 3rd PD anyway. After we will check DGS.
- The 2nd PD will not require Dolphine?
MICH signal switch is supposed btw the present MICH PD and PD2? -> Maybe can be done by the digital system.
- The mysterious shutter problem can be solved at the same time??
- Power adjustment can be acceptable if we increase the IMC out power.
- BNC-Dsub is available?
- How about 3rd PD for the MICH control?