I went through various IFO configurations to see if there are glitches or not.
Here is a summary table of the glitch investigation tonight. Some of the cells in the table are still not yet checked and they are just left blank.
| IFO configuration |
Yarm
|
Xarm
|
MICH
|
Half PRMI
|
low finesse PRMI
|
PRMI (carrier)
|
PRMI (sideband)
|
DRMI
|
| AS55 |
NO |
NO |
NO |
|
up conversion noise |
glitch |
glitch |
glitch |
| REFL11 |
NO |
NO |
NO |
|
up conversion noise
|
glitch |
glitch |
glitch |
| REFL33 |
NO |
NO |
NO |
|
- |
glitch |
glitch |
glitch |
| REFL55 |
NO |
NO |
NO |
|
up conversion noise
|
glitch |
glitch |
glitch |
| REFL165 |
NO |
NO |
NO |
|
- |
glitch |
glitch |
glitch |
| POX11 |
- |
NO |
NO |
|
|
glitch |
glitch |
glitch |
| POY11 |
NO |
- |
NO |
|
|
glitch |
glitch |
glitch |
| POP55 |
- |
- |
|
|
|
|
|
|
| |
|
|
|
|
|
|
|
|
Low finesse PRMI
The low finesse PRMI configuration is a power-recycled MIchelson with an intentional offset in MICH to let some of the cavity power go through MICH to the dark port.
To lock this configuration I used ASDC plus an offset for MICH and REFL33 for PRCL.
The MICH offset was chosen so that the ASDC power becomes the half of the maximum.
In this configuration NO glitches ( a high speed signal with an amplitude of more than 4 or 5 sigma) were found when it was locked.
Is it because I didn't use AS55 ?? or because the finesse is low ??
Also, as we have already known, the up conversion noise (#6212) showed up -- the level of the high frequency noise are sensitive to the 3 Hz motion. |