Besides the ongoing tripping, everything else looks normal.
Laser Status: SysStat is good Front End Power is 35.24W (should be around 30 W) HPO Output Power is 140.2W Front End Watch is GREEN HPO Watch is GREEN PMC: It has been locked 0 days, 3 hr 16 minutes (should be days/weeks) Reflected power = 23.22Watts Transmitted power = 41.32Watts PowerSum = 64.54Watts. FSS: It has been locked for 0 days 3 hr and 16 min (should be days/weeks) TPD[V] = 1.968V (min 0.9V) ISS: The diffracted power is around 3.9% (should be 3-5%) Last saturation event was 0 days 3 hours and 12 minutes ago (should be days/weeks) Possible Issues: PMC reflected power is high
Came in this morning to find the oscillator off. The front end was still running. Looks like the watchdog kicked in
some ime around 5:30 pm Saturday.
The power decay from head 1 is the reason for the decay in laser output power. I upped the current of the 3 other
diode boxes by 0.5 A.
Laser restarted without any major hiccups. Other stuff came on-line pretty quickly. Witnessed a couple of
occasions where the injection locking was lost.
In an attempt to stabilize HPO DB1, I adjusted the operating temperatures of the 7 individual pump diodes in DB1. The changes are summarized below:
| Operating Temperature (°C) | ||
| Old | New | |
| D1 | 24.0 | 24.5 |
| D2 | 24.0 | 24.5 |
| D3 | 22.5 | 21.5 |
| D4 | 24.0 | 23.5 |
| D5 | 24.0 | 23.0 |
| D6 | 24.0 | 24.5 |
| D7 | 24.0 | 24.5 |
This took the output power of the HPO from 138.9 W to 140.4 W, an increase of 1.5 W simply from temperature tweaks. We will continue to monitor.
VPW, LVEA, Mechanical Room. I expect to be here less than one hour and will make comment to this entry when leaving.
1705 heading to Y-end to check on purge air
1725 hrs. local - Leaving site now
After a negative rail was added to the PZT driver and a new Beckhoff scanning tool became available (thanks Daniel!), I was able to simplify the SHG auto locker and modified it such that the positive and negative rails are taken into account. SHG guardian no longer toggles the offset slide bar to look for resonance but instead sends in a scan to look for resonance. Once the resonance is found, the PZT is offset by that X amount of voltage and the loop is engaged. The code currently looks at Trans PD output power. At some point I'd like to make it look at the reflected green power and make it dependent of the input power (which can be done with the LASER IR PD). If SHG is locked with too much or negative voltage being sent to the PZT, it will drop lock to find another sweet spot. The low limit is currently set to 0V, and high limit is set to 85V.
More warning messages and fault conditions will be added in the future. For now it is relatively robust (I think).
Terry, Nutsinee, Sheila
After looking at the fiber collimators we decided to try swapping them so that the one that has a greenish tint in the lens is used for 1064 and the one that looks very clear is used for 532, based on advice from Lisa, Lee and Maggie. After doing this we were able to align the cavity and saw that our mode matching isn't too bad although we haven't tried to optimize it by moving any lenses yet.
Terry, Nutsinee
Here I attached the waist measurement and fit of 532nm coming out of the correct green coupler. The Thorlabs beam profiler we use is not great with beam diameter < 1000um for 532 so we took that into account this time. The waist size we got was 183um (radius) located 270mm away from the coupler.
I also attached a photo of the couplers we have. Couldn't capture the reddish color very well but the left coupler was for 532 and the right coupler was for 1064.
Kyle, Chandra
IP4 is back from rebuild and shipped under vacuum (measured mid e-5 Torr range). We pumped down with an aux cart, isolated the turbo, and then turned on high volts and measured 1.8-2 micro-amps at 7 kV on each channel. The pump is now vented with dry N2. Monday we will vent the blank on IP4's new gate valve, verify there is no leak into main volume, and then install IP4.
Kyle, Chandra
We tested the leaks in GV12's gate o-rings by flooding the gate annulus with dry N2 (with active turbo connected and ready to be valved in to evacuate) and discovered the adjacent volumes' pressures rise too high too quickly. The Y2 beam tube rose to 7e-8 Torr and CP4 side rose to 1.4e-6 Torr in less than one minute. We may try to jog the gate on Monday to see if we can get a better seal, at least on inner o-ring. Will also re-evaluate the bake enclosure dimensions so see if gate annulus tubing can stay (GV11's definitely gets in the way and had to go).
We realized that we did not get any email or text alarms when we should have - pressure was well past the 5 minute and 15 minute set point thresholds on PT-245B and PT-256B. Will contact Dave B. about this.
Dave Barker rebooted alarm system this morning after a crash yesterday morning.
TITLE: 01/27 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:
LOG:
14:13 Terry out to Squeezer bay
16:00 Karen ad Vanessa out to EY
17:00 Karen and Vanessa back
17:04 Karen ad Vanessa back to EY - with stock
17:05 Marc out to LVEA-returning chassis to SUS rack near HAM
17:12 Dust Monitor at EY not responding
17:21 Betsy out to EY
17:32 Betsy power cycled dust monitor 2 at EY
17:40 Patrick reset the HV at EX
17:43 Travis, Danny, and Angus to EY
17:47 Patrick back
17:57 Richard out to LVEA - camera check PSL
18:01 Richard back
18:06 Terry back
18:20 Betsy back
18:23 Greg out to LVEA - resetting TCSY LASER
18:28 N out to optics lab
18:30 Greg back
18:37 Kyle and Chandra moving new ION pump from large high bay to S side floor near HAM4
18:40 Betsy out to EY
19:19 Terry and N back
19:19 Greg out to LVEA - movin curtains from TCSY to TCSX
19:20 Angus, Travis and Danny back
19:40 Dany out to LVEA - pics
20:00 Danny back
20:00 Betsy back
20:05 Jeff back
21:14 Tvo and Sheila out for lunch
21:45 Kyle out to MY
22:02 Peter and Jeff B out to LVEA- ITMX camera
22:10 N, Sheila and Terry into optics lab
22:16 Kyle back
22:30 N back
22:54 Kyle and Chandra to MY
00:10 Jeff and Peter finished with the ITMX and ITMY cameras.
J. Kissel, for A. Bell, T. Sadecki, and D. Sellers While on my way to and from B&K hammering the EY PCAL periscope, I snapped a few publicity photos of Angus, Travis, and Danny who were fine-tuning the alignment and measuring violin modes of the brand new fibers of newly suspended H1 SUS ETMY. Thanks and keep up the good work, gents!
The violin modes were remeasured (with 0.25 Hz accuracy) position (Hz) fibre S/N +X/+Y 504.5 S1400157 -X/+Y 503.0 S1400159 +X/-Y 513.25 S1800486 -X/-Y 510.5 S1800491 as these will shift after in-chamber alignment, we didn't go for higher accuracy. The laser we used was quite noisy and should be replaced before using the kit again.
In order to compensate for the missing mass of the new holey AERM optic being installed in the ETMY suspension, I had to rework the PenRe mass to be heavier. SYS had designed a heavier new set of parts to swap, and I'll report that the rebuild went smoothly - the weigh compensation was pretty spot on and the install of the parts which we have had fit troubles with in the past, went in easy (thanks to Eddie's tweak on the design based on my feedback).
For the record, the weights of these masses are as follows. Note, the idea is to make the old PenRe mass plus the old ERM mass weight equal the total of the new sets, such that the suspension hangs in the same vertical position as before.
| OLD ETM01 mass | 25,993g | NEW AERM07 | 14,873g |
| OLD PenRe mass | 53,236g | NEW PenRe mass | 64,356g |
| Total | 79,229g | 79,229g |
Assembly weighs of the new PenRe:
| OLD PenRe | New PenRe | |
| Keeping Same Main Body | 29,857g | 29,857g |
| Keeping Same batch of small parts | 3,002g | 3,002g |
| Keeping Same wire clamp assys | 168g | 168g |
| Cans and Plates (new and old species) | 19,087g | 30,284g |
| Addable mass assys, to make total weight | 1,122g | 1,045g |
| Total from above | 53,236g | 64,356g |
Doh - Typo, the ETMY AERM is AERM06, not 07.
The difference in weight between these 2 is a negligable 8g however.
I created a medm screen to control all of the illuminators and added it to the sitemap under SYS. The controls for the illuminators in the corner station are not connected to the hardware yet. I also removed the link to the older analog video camera medm screen.
J. Kissel, R. McCarthy, M. Pirello FRS Ticket 9771 After solving all of ZM2's signal chain problems (all of which were mis-jumpered boards inside its new HAM-A coil driver and US Sat Amp, see LHO aLOG series starting with 40237), I'd accidentally told Marc to jumper the SatAmp to the AOSEM setting (ZM2, an HTTS, uses BOSEMs). He's jumpered it to the BOSEM setting this morning, so I've taken another diagnostic suite. Turns out, though the OSEM sensor response dropped by an inconsequential ~13%, ZM2's BOSEMs don't care whether they're read out with a Sat Amp jumpered in the AOSEM or BOSEM configuration. Richard and I recall that perhaps all US sat-amps are jumpered to the same configuration, because (as Richard specifies) one species of OSEM doesn't use the feature implied in that configuration, it just needs to be jumpered to either/or. So we recall having set all US sat-amps one way (or the other). We'll figure out which (by checking the OMs and RMs), and set all the new US Sat Amps (for OFI, ZMs, and VOPO) the same way. For all intents and purposes, ZM2 is now fully functional.
J. Kissel, M. Pirello, R. McCarthy Marc has verified that all US Sat Amps are jumpered to the BOSEM position. As such, we need not make any change to the current configuration of the Sat Amp, and we should consider the electronics and suspension in its final functional state. Thanks for all your help Marc!
