Oli P, TJ S
Single Bounce AS_C level
To check that we can get light through to HAM6, we brought the IFO to the same alignment as in alog79193, where they also had HAM5,6 HEPI locked. We started with the fast shutter closed. With alignments the same we went into a single bounce configuration with ITMY aligned and went up to 10W. There was no light on AS_C initally, so Oli had to move SR2 about 200urads before there was light on the sensor. SR2 moved about 60urads to center on AS_C. With AS_C centered, H1:ASC-AS_C_SUM_OUTPUT was at 0.0078 vs the 0.0045 reported on July 17 reported in the linked alog above (73% increase). We ran into some P motion when we turned sensor correction on, but maybe this is expected while we have some HEPIs locked. The AS Air camera had the slightest bit of a spot on the top left corner of it when we were centered.
| Aug 16 | July 17 | May 7 | April 17 | |
| AS_C_SUM_OUTPUT | 0.0078 | 0.0045 | ||
| AS_C_NSUM_OUT | 0.0230 | .017 | .0226 | 0.0227 |
Fast Shutter Test
While centered on AS_C we opened the fast shutter. We immediately saw light on AS_A and AS_B (1600 and 2000 counts respectively). We closed the shutter and it went away. 1st attachment
The fast shutter still exhibits a bounce when closing, as discussed in alog79397. On this particular instance, after the fast shutter initially blocked the beam, 37ms later it allowed light through for 10ms more, before closing for 38ms, then it lets one more bit of light through for 5ms - 2nd attachment shows it better. AS_C also seems to see some of this, perhaps from scattered light.
