1/2 open LLCV bypass valve, and the exhaust bypass valve fully open.
Flow was noted after 2 minutes 20 seconds, closed LLCV valve, and 3 minutes later the exhaust bypass valve was closed.
Next over-fill on Friday, March 11th before 23:59 utc.
Attached are 7 day pitch, yaw, and sum trends for all active H1 optical levers.
Almost everything looks good, with no changes from last week. The only concerning thing that we need to keep an eye on is the BS SUM; it has dropped from >20k counts to <10k counts over the last week. As soon as I get back from Germany I can start looking into it.
Pirani gauge on BSC4 was temporarily in the wrong orientation during maintenance yesterday and thus read erroneous pressures for ~3 hrs until it was reinstalled (with valve) by Gerardo. Attached is pressure plot.
I've updated the TCS SIM section of the front end. The changes are summarized here:
This morning I noticed the Diode Chiller in alarm. I added 150ml to rest the float switch and the another 250ml as per Jeff Bartlett's advice. Because the Famis task (#4140) of checking the chillers and adding necessary water was completed yesterday (without being able to accurately diagnose the water level in the diode chiller)and the alarm went red today, there is a plan to remedy this issue being set into motion.
Transition Summary:
Title: Day Shift 16:00 – 00:00 (08:00 – 16:00) All times in UTC (PT)
State of H1: IFO unlocked.
Commissioning:
Ellie working on SRC interface measurements.
Tonight we again weren't able to engage the soft loops without pulling the sideband powers down and dropping lock, so I spent a little time on ASC.
For one thing I looked at the phasing of AS36 A to see if we can reduce the SRM signal in the Q phase. The reasoning for this is that the SRC loops are sensitive to the soft arms through AS_C, and if the BS is also sensitive to SRM this could be one way that moving SOFT misalings the beamsplitter. However, it looks like we are already kind of using a phase that minimizes the SRM signal in Q, (-140), so I left this as is.
I also had a look at the best combination of TMS QPDs to use, since we retuned this on saturday I was curious to see if the combination had changed today with a different alignment. I checked only TMSX pit, but it had only changed by 1%, even with the soft loops off.
Lastly, I tried to increase the bandwidth of the CHARD loops, in part because we know we need to do this, and in part because CHARD is cross coupled with the yaw loops and there is a long slow osciallation in all 3 loops due to this. A screenshot is attached with settings that result in CHARD BWs similar to the DHARD ones, this initially does seem to reduce the long slow oscillation of the soft loops, but we still have the problem that the slow loops misalign the vertex. I've added these settings, which are engaged with a lower gain and not the boosts on, to the guardian, but they will probably add noise, so we can reduce their gains when we want to go to low noise.
Top pannel is IM2 OSEMS. Bottom pannel is select OSEMs from IM1, IM3, and IM4.
State of H1: locking and getting Engage ASC, Sheila working on the ASC
Site Activities:
LVEA and OSB optics lab access:
Currently:
I made a folder called beckhoff in /ligo/lho/h0/ve/medm and copied the new medm screens for the Beckhoff vacuum controls into it. I then changed the 'VE EX' link in the 'VE/FMC' drop down menu on the sitemap to point to /ligo/lho/h0/ve/medm/beckhoff/H0_VAC_EX_CUSTOM.adl. I committed the change to the sitemap into svn. /ligo/lho/h0/ve/medm/beckhoff/H0_VAC_MENU_CUSTOM.adl is a mini sitemap for just these screens. The screens that do not have CUSTOM in the name are generated from a script. The files necessary to generate these screens are in the slowcontrols svn repository in trunk/TwinCAT3/Vacuum/MEDM/LHO.
Kyle, Patrick The new Beckhoff control parameters still need "tuning". As of this writing, the control of CP8's level is via the Proportional term only. Initial attempts resulted in overfilling which then resulted in a closed LLCV which then resulted in a warm transfer line. Patrick and I opened the exhaust check valve bypass valve to relieve the back pressure and then cooled the transfer line via the manual LLCV bypass. With the transfer line cold and the pump level responding to changes in the LLCV, I manually filled the pump to 95% full, closed the exhaust check valve bypass valve am leaving the LLCV manually set at 50% open overnight which is its recent nominal value to maintain the pump level. Jim Batch set up and included two MEDM screens so the X-end status can be monitored from home. Patrick and Cheryl also are leaving an MEDM screen in the Control Room which can be monitored from home. 2135 hrs local -> I'm leaving now and will monitor CP8's level from home (every 2 hours)
I changed the end X channel names to match the new Beckhoff channel names in /opt/rtcds/userapps/release/cds/h1/alarmfiles/ve.alhConfig. There are no new Beckhoff channel names corresponding to HVE-EX:GV19_CCOFFALARM and HVE-EX:GV19_OVERPRESSURE so I commented these out of the file. I will have to see if there are other channels that can be alarmed on instead of these. I committed the changes to svn in cds_user_apps/trunk/cds/h1/alarmfiles/ve.alhConfig. I restarted the alarm handlers on alarm0 to use the updated file.
The Beckhoff control system upgrade was performed at X-end today and I just wanted confidence for this value -> Both values agreed to with 1%.
Kyle. Gerardo, Chandra Gerardo -> Installed 12" CFF at HAM10 D8 and gauge pair isolation valve on BSC4 Chandra -> R&R LVEA Turbo levitation batteries Kyle -> Drilled and tapped holes, mounted scroll pump local to Diagonal Turbo and upgraded gauge controller on Diagonal Turbo Kyle, Chandra -> Ran QDP80s, YBM, XBM and Diagoanl Turbos and vent/purge air supply (KOBELCO). The KOBELCO displayed a "HIGH LUBE OIL TEMP" Warning after having run for a while. Chandra noticed that the chilled water booster pump was off and that the output pressure once on was only 60psi (this may be the result of a reduced frequency running of the chilled water circulating pump - nominally this would be 90 psi - we need to investigate) The measured dewpoint after > 1 hour of run time was <-30C. Gerardo noticed that the Diagonal volume was still left connected to the purge air header from when it had last been purged, the isolation valve was then closed. NOTE: The XBM Turbo spun up to full RPM but tripped off during the braking phase. This Turbo has a history of high vibration - typically during the accelerating phase.
The Turbo pump controllers are being left energized overnight in the LVEA to allow the Turbo rotors to come to a full stop
No FRS required. Lower than expected pressure in output from booster pump in chilled water system is likely due to difference in building chilled water pressure (variable speed pumps).
A line at 47.683 Hz has appeared in the output of the stochastic O1 (time shifted) analysis. We have used the coherence tool to search for look for the source of this line in H1 and L1. The line at 47.683 Hz appears very clearly in H1 in the h(t) coherence with H1:PEM-EY_MAG_EBAY_SEIRACK_X_DQ (week 13 example attached) and H1:PEM-EY_MAG_EBAY_SEIRACK_Y_DQ, in weeks 12, 13, 14, 16. It also appears clearly in the L1 h(t) coherence, apparently associated with some other lines (eg, 47.42Hz) in weeks 5-10, 14, and 16 in these channels: L1:SUS-ETMX_L1_WIT_P_DQ (week 5 example attached) L1:SUS-ETMX_L1_WIT_L_DQ L1:SUS-ETMX_L1_WIT_Y_DQ L1:PEM-EX_MAINSMON_EBAY_3_DQ (week 5 example attached) L1:PEM-EX_MAINSMON_EBAY_QUAD_SUM_DQ L1:PEM-EY_MAG_EBAY_SUSRACK_X_DQ
These lines are also visible in the run-averaged spectra for H1 and L1. See attached figures (ignore the S6 labels in the legend, corresponding to traces that are off-scale). Can anyone think of a device, common to both observatories, that produces such a frequency, e.g., a flat-screen monitor?
Finished the wiring and installation of the electronics for the new CPS timing distribution at EX, EY, and LVEA. CPS interface units need to be modified before switching to the new timing distribution.
The attached plot (and script) shows the nominal TCS power levels required for O2 to correct for just the ITM substrate lenses.
The following values are assumed:
The bottom line is that we will cease to need central heating around 45W on ITMX and 30W on ITMY and will need to start using the RHs to compensate for the thermal lenses. No consideration is yet given to HOM correction with annular CO2 heating.
Subject: Re: RC as-built designDate: May 14, 2015 at 7:54:37 PM EDT
Hi All,
The value of the thermal lens that was always used when adjusting the cavities is 50 km.
The issue which caused all of the confusion last summer was one of definition; i.e. what does it mean to have a 50 km thermal lens. The plots Muzammil put together, on which the decision to include the thermal lens was based, modeled the thermal lens as being inside the ITM. The model we used to adjust the optic positions had the 50 km thermal lens immediately in front of the ITM. The effective focal length in the two cases differs by a factor of n (the index of refraction), with it being stronger in the model which was used to calculate the positions. Because of this the positions were tuned to have a slightly stronger thermal lens than was originally decided on based on Muzammil's plots.
Fortunately, Lisa and I discovered that this is essentially a non-issue since the length changes needed to tune for the two different thermal lenses are less than the length changes needed to compensate for tolerances in the measured radii of curvature of the optics.
Thank you Aidan for working on this.
Speaking of the thermal lensing, we (the LHO crews) have been discussing a possible TCS pre-loading strategy. Here are some summary points of our (future) strategy:
Any comments/questions are welcome.
