Yesterday I measured the IMC input beam (measurement location: in front of the bottom periscope mirror), and compared that to the reading on the IMC IN PD.

• measured beam power = 1.63W (power meter)
• PD reading = 1.88W
• difference of +0.25W on the PD
• calibration needs to be evaluated
• unknown state of dark offsets
• this is true for the IMC IN PD and all PDs in the IO path
• true for all PDs on the PSL (Jason)

IO path PD Status:

• PD layout in the IO path is currently being reworked
• the ISS PD was moved back into the ISS box today
• where it was located, there is one new PD to add: the large area DC PD
  • this new DC PD  is on site, and is in Jason's office
  • it came with an AC power supply
  • other options for powering the PD are being looked at
  • other IO PDs are being powered with a box that is under the PSL table, so this may be an option
• while the ISS PD was in the IO path, it was looking at the transmitted beam from IO_AB_W1 (where the new large area PD will be installed)
• there was a Thorlabs DC PD on the reflected beam from IO_AB_W1, and it's unknown if this is intended to stay
• the Thorlabs DC PD on the transmitted beam of the PMC is a temporary setup, and will not stay (since it's not in the planned O3 configuration)
• NOTE : this PD, looking at the PMC transmitted beam, was being read into the DAQ through a channel labeled EOM power PD, starting when the ISS PD moved out of it's box

The pressure in corner station is 6.5e-7 Torr. Attached is a projection of *rough* dates at lower pressures. Ideally, we want to wait to open to the arms until the corner pressure is 1e-7 Torr on the turbos alone, and then valve in IPs and CPs. Last May when we vented corner for one day, we opened back up to arms at 2e-7 Torr in 16 days. Will consult Vacuum Review Board on how to proceed with opening up GV5 for y-arm commissioning.

J. Oberling, P. King

Today we worked on recovering the PSL ISS, and began by re-installing the ISS AOM.  The AOM mount was moved to a place where the beam was ~1mm in diameter (unfortunately I forgot to take pictures, will take some tomorrow and upload as a comment) and installed the AOM.  The mirror that sits downstream of the AOM and reflects the 1st order diffracted beam into a beam dump was also re-installed and aligned.  A power meter was placed in this beam path and the alignment of the AOM tweaked to maximize the power in the 1st order beam.  We then adjusted the ISS offset to find the point where the AOM was diffracting ~2W; this was found at an offset of 8.0.  The offset was then set to 0, and increased to 20 in steps of 1; a power reading for the 1st order beam was taken at each step.  This allows for calibration of the diffracted power graph on the ISS MEDM screen.  Peter has the data and is analyzing it.

The beam from the PMC to the ISS box had to be re-aligned, as we had not re-aligned this path since moving the ISS box to accommodate the damping bars for the new PMC.  This complete, we then roughly aligned ISS PDB.  The PD assembly was then removed from the ISS box so we could re-install ISS PDA (recall that PDA had been removed from the ISS box and installed in place of IO_AB_PD3 prior to O2).  With PDA back on the PD assembly, this was installed back in the ISS box, and both PDs aligned.  They both now read ~10.0 V.  Next step on the ISS (for tomorrow) is to get the loop to close and measure TFs to optimize its operation.

15:00 JeffB to LVEA

15:45 Fil to MSR 

16:15 Betsy, Travis to EX

16:15 Gerardo to EY

17:00 Jason to PSL

18:00 Marc to HAM6

20:15 Jason Peter to PSL

20:45 JeffB to ITMX camera

21:15 Betsy, Travis to EX

21:30 Aidan, Marie, Dan, Alexei to EY

files saved in:

• .../QUAD/H1/ITMX/SAGM0/Data
• .../QUAD/H1/ITMY/SAGM0/Data
• all TFs looked acceptable, with some noise, but nothing missing or added

   I added 100ml water to crystal chiller and no water to the diode chiller. Both filters are clean and clear. 

Rough pump down was faster than normal.  Implies that the majority of the gas load comes from the O-ring sealed QF flex lines that connect the scroll pump assembly to the HAM6 connection as these were pumped overnight.  Typically, these get pumped simultaneous with HAM6.  In other words, it seems that the time needed to rough pump HAM6 down to the point of switching over to the turbo pump is significantly determined by how wet the connecting flex lines are.  We have always suspected this but never realized to what degree. 

Large units over HAM3, HAM4, HAM5, HAM6 and the Beer Garden, as well as, the small change rooms etc. on north side of OMC tube.

Filiberto C., Daniel S., Marc P.

Today we successfully applied E1600252v2 to the OMC DCPD ISC Split Whitening Chassis S1101627.  This change better accommodates the violin modes of the main LIGO optics in the vicinity of 500Hz that have a tendency to saturate the whitening chain's filters.  The new filter replaces a 1Hz-10Hz zero-pole, with a 50Hz-500Hz pole-zero on the second filter channel.  LLO had already completed these changes August 2016,  ALOG.

FRS Ticket 6031

WP7583

On Chandra's request, the high alarm level for PT245 was raised from 5.0e-09 Torr to 5.0e-07 Torr.

-<Channel name="H0:VAC-MY_Y4_PT245B_PRESS_TORR" low="1.0e-10" high="5.0e-09" description="VE gauge, MY CP4, CC">
+<Channel name="H0:VAC-MY_Y4_PT245B_PRESS_TORR" low="1.0e-10" high="5.0e-07" description="VE gauge, MY CP4, CC">

All of H1 models are now running back at RCG3.2, some with their most recent code. Those with new code are waiting for a DAQ restart to resync the channel lists (scheduled for noon).

As of this morning there were several models which would not run: all ISI-HAM (h1isiham[2-6]) and h1susauxh34. These models got new code yesterday, but others did also and they had no reversion issues.

To verify that a clean rebuild of the new code against RCG3.2 fixes the problem, I used h1isiham6 on h1seih16 as a test case. To minimize the risk of Dolphin glitching the corner station if this did not work, h1seih16 was removed from the switch fabric prior to testing.

1. Remove h1seih16 from the Dolphin fabric and powered off the computer

2. Disconnected the Dolphin cable from the rear of h1seih16 and powered it up

3. Rebuilt/installed and restarted h1isiham6 code. At this point everything was running, SWWD was of course tripped due to the disconnected Dolphin cable.

4. Repeated step 1.

5. Plugged the Dolphin cable back into h1seih16, powered up computer, started models

Initially all was good, but after a few seconds the IOP Dolphin IPC for the SWWD went to no reception (64kHz error rate). I restarted the IOP several times and the problem appears to have resolved itself with no input from me.

I ran some diagnostics on h1susauxh34 during its crashes, then rebuilt that code against 3.2 and it is also now stable. Finally I rebuilt h1susauxe[x,y]  and h1pemmx.

ISI-HAM systems now have the Ramped-Watchdog code.

The HEPI database running the Pump speed controllers monitors the differential and Pump Station output pressure; the usuals originally used to set the alarm level must have drifted.  The Pump Station filters were recently changed and this may have changed the steady state.
Will investigate.  FRS 10725.

[Aidan, Marie, Dan, Keita, Alexei, TJ]

Yesterday we started the process of installing the new green LED source for the ETM HWS, per T1800229. 

We started by making sure the ALS beam was aligned to the TMS and there was a return beam getting to the ALS photodiode. We inserted two irises, one immediately after ALS-M11 and another about half way up the periscope. These were aligned to the existing ALS beam to secure the axis. Unfortunately, subsequent analysis at the end of the day showed that one of the PZT mirrors railed at some point during or after this process of aligning the irises. We're not currently sure if they really represent the ALS axis. We will investigate this further this morning.

We inserted all the optics per T1800229 (the fiber LED source, 4 steering mirrors, a polarizer, a 50/50 beam splitter). Also, we added the polarizing beam splitter which transmits the P-polarized (horizontally polarized) HWS light and reflects the S-polarized ALS beam. This PBS has not yet been aligned to get the ALS beam back to centered on the irises.

The new HWS beam was aligned to the centers of the existing optics. We have yet to align it to the PBS or the irises.

A couple more notes:

• when designing the system, I forgot that HWS-M3 and HWS-M4 were not HR mirrors for 532nm. These are uncoated optics to attenuate the return beam getting to the Hartmann sensor. We had to replace both of these optics with HR mirrors for 532nm. 
• We found, much to our delight, that the 20 uW HWS beam coming out of the fiber-optic launcher is visible through the laser safety goggles (because of the 30nm linewidth). This makes aligning it much easier. However, the polarizing beam splitter strips off much of the blue portion of the light and the remaining green portion is much more difficult to see through the goggles. So alignment is easy up to the PBS.

Some photos from installation are attached.

1. Photo of fiber launcher [IMG_3829]
2. HWS probe beam from fiber launcher on card between first mirror and second mirror [IMG_3828]
3. HWS fiber launcher and injection optics installed [IMG_3827]
4. Fiber launcher [IMG_3826]
5. 2" diameter uncoated beam sampler that was replaced with 2" diameter max R mirror - the former ALS-M11 [IMG_3825]
6. 1" diameter uncoated beam sampler [IMG_3824]
7. HWS PBS and iris [IMG_3823] 

WP7578. Hugh, Jenne, Jonathan, Dave:

After upgrading the H1 models to RCG-3.4.2 and the front ends to Gentoo 3.0.8 we ran into a Dolphin network manager issue at 3pm PDT. Given the lateness of the hour, we decided to revert back to rcg-3.2/gentoo 2.6.34. All systems are now back with the exception of the HAM Seismic systems which are crashing on start-up. We will resolve this in the morning.

During the reversion process all three of the Gen-2 front end systems (h1suse[x,y], h1lsc0) lost connection with their IO Chassis and required a full system power cycle. This is unusual as recently only h1susex has infrequently required this type of reboot.

To revert, I restored the archived target directories, the IPC file, the original INI and PAR files for those systems whose code had changed and the DHCP service on h1boot.

[Gary T, Danny S, Matt H, Stuart A, Norna R]

During the close-out work of the BSC9 chamber (see LHO aLOG entry 13085) we were able to further investigate the source of the excess noise that had previously been observed on the ETMX (QUAD) L2 (PUM) UL channel (see LHO aLOG entry 13047).

Previously, I had swapped field cables at the Satellite Box between ETMX L1 and L2 stages running to the chamber. This indicated that the noise was downstream, i.e. with the field cables themselves or in-chamber. We repeated this test, but this time swapping field cables at the air side of the vacuum flange. Further measurements then eliminated the field cables and confirmed the issue resided in-chamber.

Gary inspected and re-seated the in-chamber connectors from the vacuum flange to the OSEM, but this offered no improvement. Finally, the L2 UL AOSEM (s/n #270) was removed and a spare unit connected up in it's place, but again, unfortunately this offered no improvement.

This indicates that the excess noise is most likely a in-vacuum harness problem, which would be invasive to attempt to replace. Therefore, it was decided to generate an integration issue and proceed with the close-out of the chamber, with the excess sensor noise on this channel.