SQZ SHG guardian improved

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).

OPO aligned for 532

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. 

IP4 tested and vented

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.

Mid-Y work

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.

Shift Summary - Day

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.

ETMY Welding Pics

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.

ETMY PenRe reworked

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

 

Added illuminators to sitemap

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.

Updated h0vacex and h0vacey

WP 7312

I updated and restarted the h0vacex and h0vacey PLCs to create separate sync units for each Inficon gauge. The X2-8 and Y2-8 Inficon gauges are still powered off, but no longer disabled in TwinCAT. With the addition of the separate sync units this no longer prevents the remainder of the system from running. I burtrestored both h0vacex and h0vacey to 6am local time this morning.

The high voltage at each end station has likely tripped off and will need to be reset.

I reset the high voltage at end X.

Shift Transition - Day

TITLE: 01/26 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    Wind: 24mph Gusts, 20mph 5min avg
    Primary useism: 0.04 μm/s
    Secondary useism: 0.45 μm/s
QUICK SUMMARY:

 

fiber collimators

Terry, Sheila

We seem to have a mix up with our fiber collimators.  We measured the beam profile out of our 532 nm collimator this afternoon, because our mode matching into the OPO is very poor, and found it to be 52 um.  This afternoon Terry and I measured the waist out of both of our collimators for both wavelengths. 

	532 nm horizontal waist	532 nm vertical waist	1064 nm horizontal waist	1064 vertical waist
collimator supposedly for 532 (SN4)	52um @ 0.11m	53 um @ 0.10m	256um @ 0.27m	253um @ 0.27m
collimator supposeldy for 1064	209um @0.22m	255um @ 0.33m	155um @ -0.22m	156um @ -0.23m

The 532 collimator that we have is SN4.  Maggie sent a link to a git where she has measured data from SN4 for 532nm, this data shows that the waist is 264 um 0.6 meters from the collimator.  I am not sure right now what the serial number of our 1064 collimator is, but the data on the git says SN01 has a waist of around 280um @0.3 meters while SN17 and 18 have waists around 315/320um.  

It seems like the most plausible explanation is that we have the collimators swapped somehow even though we have been careful not to do that since taking them out of the bag.  If the one that we think is the 532nm SN4 is really 1064nm SN01, these measurements aren't as crazy, although there is still a discrepancy between the waist position of the 1064 beam coming out of our SN4 collimator and what Maggie measured for SN01.  

The data for all four of the measurements that Terry and I took this afternoon are in the comments in the attached script. 

The collimators can be (quite easily, I would say) distinguished by looking at them, if you know the "color code".

The 1064nm ones have a milky looking color, while the 532nm ones have a pink-ish color. 

Hope this helps to confirm your theory..

OMC Alignment and Locking Update

Jenne, Keita, TVo

Successful locking of the OMC on the 00-mode!

First, the OM1-OM2-OM3 path into the OMC using QPD_A and QPD_B as a reference and closing the loops.  This left OM1 pretty close to railing in yaw and so there were some attempts to offload OM1 onto the other two but it would rail the OMC actuators when the loops were engaged.  We remedied this by zeroing the OMC alignment sliders while the OMC_ASC loops were on (this worked pretty smoothly). So Jenne offloaded again so that we do the least amount of optics sliding/rotating on the HAM6 optics table.

Fil turned the high voltage on for the PZT so that we could try to lock. There was some confusion when the OMC_DC_IN1 was railing when sweeping the PZT_OFFSET, this is still not clear why so we turned off all stages of whitening to avoid saturating.  Then we were able to achieve lock after Keita turned off the purge air,  we've left the purge turned on but lower than the previous setting.

Jenne pointed out that having about 1mW of input power from HAM5 should register about 1mA on the OMC_DC_SUM_OUTPUT when on the right mode and we're getting about that with PZT_OFFSET = 1.8. 

Laser locking

Nutsinee, Marc, Terry, Daniel

We finally wrestled the new TTFSS to the ground. Ugf is around 500kHz with good phase margin and somewhat less good gain margin. The crossover is around 10kHz. It cannot be raised by much due to two smaller peaks in the 70-95kHz range. A couple of electronics modifications were needed.

For the frequency counter of the beat note to work we need >-12dBm pf RF power in the cable going towards the CER. Ideally we have at least 0dBm. The beat note strength from the photodiode was only around 30mV and we had to change the directional coupler in the TTFSS preamplifier to a splitter to give us more umpf.

Tested GV12 annulus volumes for leaks

Kyle, Gerardo 

We vented GV12's annulus volume (minus the gate volume) with bottled UHP N2 and observed no leaks into the CP4 volume.  Next, we pumped out the vented volume, combined the gate annulus volume and then administered UHP N2 into the entirety of the annulus volumes.  We observed pressure rises on both the Y2 module side of the closed gate valve as well as the CP4 side - thus indicating that both the inner and outer gate O-rings leak.  We evacuated the system, isolated the gate annulus volume, restarted the AIP (pumps all but gate volume in this configuration) then isolated and shut down the connected turbo+cart.  

Another useful test would be to fully vent the annulus volumes adjacent to the leaking gate annulus volume and then "dump" this gas all at once as a step change into the gate annulus volume and then observe how much time we would have to decouple plumbing and install a blank on one of the two gate annulus pump ports and a pump port valve on the other gate annlulus pump port as was done to GV11 yesterday.   

ETMy fiber welding update

Today, we measured the violin modes of the new monolithic ETMy with the goal to determine what contributed to the large-ish pitch offset we were seeing.  Nothing egregious was found from violin modes themselves, so we decided to attempt to fix the pitch by re-stress-relieving the stock welded to the horns.  This technique has been done before, once here at LHO and once at LLO with success.  This time around, we went from ~5mRad differential pitch to ~500 uRad differential pitch.  Now, if only we could get a factor of 10 improvement in other aspects of LIGO in the course of a day. . . 

ZM2 Fully Functional, Doesn't Care Whether Sat Amp Jumpered to AOSEM or BOSEM Configuration

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!