Agenda/Minutes of the VIS Meeting on 2020/4/17
2020/4/17 14:00 -
Participants: Takahashi, Sato, Hirata, Tanaka, Shoda, Aso, Fabian, Miyo, Lucia
(Miyo) I'm gathering information about the hardware part. (e.g. cabling, calibration of sensors and actuators.)
JGW-T2011597 Calibration factors of LVDTs .
JGW-D2011573 Cabling diagram which includes connections among AEL circuits and pin assignment at the feed-through.
Purpose : To make a consensus about the cabling with AEL and CRYO group for O4.
Status Need information about the pin assignment for all suspensions -> Sato-san? and Shoda-san?
Revising the Type-A installation procedure.
In the context of writing a paper I gathered information about OSEMs and LVDTs and uploaded a document at : JGW-T2011612, which I will be updating.Currently the content is
- Linear ranges of 24 OSEMs and
- Sensitivity of the six SRM OSEMS.
- I gave feedback to Miyo-kun about LVDTs: all the current calibration factors in medm screens are consistent with klog reports. Just as a reminder:
- The polarity of LVDTs is set in hardware: increase in LVDT output always means upwards motion or positive yaw in the IPs. Therefore, calibration factors in medm screens should always be positive.
- An exception seems to be BS IP H2 LVDT, whose medm screen I have to check for a minus sign somewhere.
- The offsets in medm screens correspond to the nominal places of keystones per the 3D-CAD, not the mid-point of the linear range.
- Started the design of LVDT combiner with additional filters.
Post O3 (4/21~)
- Type-B: Fabian. Share the contents.
- Type-A: Lucia. Ask Fujii-kun about his situation.
- Operation mode at the shutdown of KAGRA
- Basically safety mode is employed.
- DC control is turned off for the GAS filters. Monitor the drift. If necessary, require temperature adjustment.
- DC control is kept for the IPs. Monitor the drift. If necessary, offload by remote.
- DC control is kept for the BF yaw after the offload. Monitor the drift. If necessary, offload again by remote.
Plan: Confusing with the post-O3 task. Should be combined with priority.
For a summary of the current status of inertial damping in Type-B suspensions see the appendix (p14 onwards) in this presentation shown the Commissioning Meeting on the 27th of September 2019.
- Had the control meeting.