Alexa, Kiwamu, Koji, Sheila, Stefan
In the morning we worked on getting the green beam correctly positioned onto the periscope mirror and onto ISCT1. First we adjusted PR3 such that the beam was centered through the Swiss cheese baffle opening and the viewport. We then had to move the periscope mirror by 1.5inch toward the east, and move the top mirror up slightly. Following this, we finessed our adjustment of PR3 so that the ALS-X green beam was 4mm toward the east in the horizontal direction and 6mm up in the vertical (as specified by Ketia's alog). We also ensured the beam hit the periscope on ISCT1 with M11.
In the afternoon we were able to see IR POP flashes in HAM1. We had to adjust M10, M15, M16, BDIV1. The pop beam was centered on the LSC_POP_A PD; however, we do not see a strong enough signal. We do see a signal when we shine a flashlight onto the PD. We also aligned the pop beam onto the viewport towards ISCT1. Koiji adjusted the periscope location on ISCT1 so that the pop beam was well centered.
Another thing we were not able to get finished was fine placement of the black glass beam dump for the reflected light off of the POP LSC PD. I was unable to see this beam even with an IR viewer. I will place the beam dump at a place which can be derived by the angle of the incident beam and the diode. I took several pictures of the PD for this particular purpose. Once I figure out a good location for the beam dump, we will enter HAM1 again today.
Also, Stefan and I installed an iris on ISCT1 for the X arm green light to record its landing point right. It is placed after the bottom periscope mirror. This should allow us to help speeding up the alignment recovery process. Note that when we put the iris, the green light coming to ISCT1 was the straight shot from TMSX and the arm cavity was intentionally misaligned.
I forgot to mention about one important quantity:
X arm green light at HAM1 was measured to be 27 uW with ETMX misaligned (i.e. non-resonant beam).
Supplimental info:
- Alignment adjustment by PR3
Pitch: H1:SUS-PR3_M1_OPTICALIGN_P_OFFSET
Yaw: H1:SUS-PR3_M1_OPTICALIGN_Y_OFFSET
- PR3 alignment at the middle of the visible range for the X green
Pitch: -254.0 / Yaw -254.4
- PR3 alignment to clip the beam at the edge of the mirror
Pitch: clipped at the top of the mirror: -228
Pitch: clipped at the bottom of the mirror: -265
Yaw: clipped at the negative Y side of the mirror: -226.4
Yaw: clipped at the positive Y side of the mirror: -288.4
- PR3 alignment to give the X green at the center of the periscope top
Pitch -246.5 / Yaw -257.4
- PR3 alignment slider to the spot displacement on the projection plane
Pitch 1.030 cnt/mm / Yaw 1.220 cnt/mm
- PR3 alignment slider to give the spot at (-4.2mm, 5.99mm) on the projection plane
Pitch -240.328 / Yaw -252.276