patrick.thomas@LIGO.ORG - posted 13:46, Thursday 30 January 2014 - last comment - 14:03, Thursday 30 January 2014(9667)
Apollo flying crane over X arm in LVEA
Comments related to this report
Done
Starting work.
This morning Filiberto, Travis and I made grounding checks of the SUS cables on the ISI. We also check a few of the TMS cables that were easy to access near our bundle. Coery checked some prior as well. Long story short, we only found 1 cable route that has a ground issue and it is on a TMS segment that runs to BOSEMs. It is the connection with the D100225-S1104782 cable in it. This cable has been through testing, so likely we can find and remedy this ground. Coery said he'll add it to the TMS hit-list.
We've observed some burn marks on the shielding of the ETMy ring heater cables which occured sometime during the 3 prior weld sessions (May 2012, Dec 2013, Jan 2014). The burns are on the lowest ring heater cable that laces around the test mass and makes a connection between the test mass and the PUM. There is a burn on the right segment and the left segment. I dug up a picture that shows that the burn on the "right" segment (as viewed from the back of the suspension) was there just after the May 2012 weld session, so that one is not new. However the "left" cable burn is new from the Dec or Jan welding. We did not see when this actually occured.
Filiberto tested the ring heater cable and found that all pins are operating as per spec, although he thinks pin 1 is shorting. We are tracking down what this means (did we test it correctly, when was it last tested, is it possible that the burn is contributing to the short, even though it does not look like it is, etc.).
This is the picture of the RH "right" cable taken in May 2012.
And here is the "left" RH segment burn which happened in the Dec or Jan weld.
For the ring heater cable, the following pins were tested. Pins 2,3,4, and 5 are tied together. Pins 14,15,16, and 17 are tied together. The resistance between these two sets is 47.5 ohms. Pins 8,9,10, and 11 are tied together. Pins 20, 21, 22, and 23 are tied together. The resistance between these two sets is 45.9 ohms. Pin 1 is tied to shield and shorted to ground. Filiberto Clara
I'm making a measurement of the ITMX direct reflected beam size on ISCT1. PRM is misaligned, sending the beam to the parking dump for this mesurement. Please do not align PRM as this will make the REFL beam too powerful for the beam analyzer and may fry it.
I'm done for now making measurements with PRM misaligned. I'll realign PRM now and measure the PRM direct reflected beam
Output power is 29.3 W (should be around 30 W) FRONTEND WATCH is green HPO WATCH is red SysStat is good PMC has been locked 1 day, 16 hr (should be days/weeks) Reflected power is 10.9% of transmitted power (should be <= 10%) FSS has been locked for 10 min (should be days/weeks) Resonant threshold is .5V (should be .9V) ISS diffracted power is around 8.8% (should be 10%) Last saturation event was 16 min ago (should be days/weeks)