The first thing I looked at tonight was locking the PRMI on REFL 165.
I locked the PRMI (no arms), and checked the REFL 165 demod phase. I also found the input matrix configuration that allowed me to acquire PRMI lock directly on REFL165. After locking the arms on ALS, I tried to lock the PRMI with REFL 165 and failed. So, I rechecked the demod phase and the relative transfer functions between REFL 165 and REFL 33. The end of the story is that, even with the re-tuned demod phase for CARM offset of a few nanometers, I cannot acquire PRMI lock on REFL 165, nor can I transition from REFL 33 to REFL 165. We need to revisit this tomorrow.
| IFO configuration |
CARM offset [cts] |
REFL 165 demod phase [deg] |
| Found as-is |
N/A |
+145 |
| PRMI, no arms |
N/A |
-135 |
| PRFPMI |
+3 |
+110 |
| PRFPMI |
+2 |
+110 |
| PRFPMI |
+1 |
+110 |
| PRFPMI |
+0.5 |
+120 |
| IFO configuration |
REFL 33 I / REFL 165 I (PRCL) |
REFL 33 Q / REFL 165 Q (MICH) |
| PRMI, no arms |
+0.1 |
+0.22, although easier to acquire lock with +0.1 |
| PRFPMI, CARM offset = +3 |
-0.09 (TF measured, no lock) |
+0.033 (TF measured, no lock) |
For the PRMI-only case, I ended up using 0.1's in the input matrix, and I added an FM 1 to the MICH filter bank that is a flat gain of 2.2, and then I had it trigger along with FM2.
I turned this FM1 off (and no triggering) while trying to transition from REFL33 to REFL165 in the PRFPMI case, but that didn't help. I think that maybe I need to remeasure my transfer functions or something, because I could put values into the REFL165 columns of the input matrix while REFL33 was still 1's, but I couldn't remove (even if done slowly) the REFL33 matrix elements without losing lock of the PRMI. So, we need to get the input matrix elements correct.
I also recorded some time series for a quick RAM investigation that I will work on tomorrow.
I left the PRM aligned, but significantly misaligned both ITMs to get data at the REFL port of the RAM that we see. I also aligned the PRMI (no arms) and let it flash so that I can see the pk-pk size of our PDH signals. I need to remember to calibrate these from counts to meters.
Raw data is in /users/jenne/RAM/ .
I have not tried any new DARM signals, since PRMI wasn't working with 3f2.
We should get to that as soon as we fix the PRMI-3f2 situation. |