The laser below is dead. JDSU 1103P, SN P845655 lived for 3.5 years.
JDSU 1103P died after 4 years of service. It was replaced with new identical head of 2.9 mW output. The power supply was also changed.
The return spots of 0.04 mW 2.5 mm diameter on qpds are BS 3,700 counts and PRM 4,250 counts.
It was replaced by JDSU P/N 22037130,( It has a new name for 1103P Uniphase ) sn P919639 of mfg date 12-2014
Beam shape at 5 m nicely round. Output power 2.8 mW of 633 nm
BS spot size on qpd ~1 mm & 60 micro W
PRM spot size on qpd ~1 mm & 50 micro W
May 13, 2014 ETMX, .............laser in place 90 d
May 22, 2012 ETMY,
Oct. 7, 2013 ETMY, LT 503 d or 1.4 y............bad beam quality ?
Aug. 8, 2014 ETMY, .............laser in place 425 days or 1.2 y
Sept. 5, 2014 new 1103P, sn P893516 installed at SP table for aLIGO oplev use qualification
Amstron batteries replaced after 11 months with SP-12-5.5HR, 2 years warranty from replaceUPSbattery.com
Batteries replaced after 3.5 years with Amstron AP-1250F2, 8x 12V 6Ah
APC Smart -UPS 2200 model: SUA2200RM2U batteries were replaced by compatible RBC43, 8x 12V5A
Note: the replace battery LED did not go out ( well pasted 24 hrs ) till the self test bottom was hold down for 2-3 sec
May 23, 2016 ITMX dead He/Ne laser sn P845648 replaced after 1062 days [2.9 yrs] by 1103P, sn P859884, with output 2.6 mW, nicely round beam quality at 15 meters.
Power just before viewport 1 mW, returning light on qpd 154 microW = 7,500 counts
2005 ALL oplev servos use Coherent DIODE LASERS # 31-0425-000, 670 nm, 1 mW
Sep. 28, 2006 optical lever noise budget with DC readout in 40m, LIGO- T060234-00-R, Reinecke & Rana
May 22, 2007 BS, SRM & PRM He Ne 1103P takes over from diode
May 29, 2007 low RIN He Ne JDSU 1103P selected, 5 purchased sn: T8078254, T8078256, T8078257, T8078258 & T8077178 in Sep. 2007
Nov 30, 2007 Uniphase 1103P divergence measured
Nov. 30, 2007 ETMX old Uniphase 1103P from 2002 dies: .............., running time not known......~3-5 years?
May 19, 2008 ETMY old Uniphase 1103P from 1999 dies;.....................running time not known.....~ ?
Oct. 2, 2008 ITMX & ITMY are still diodes, meaning others are converted to 1103P earlier
JDSU 1103P were replaced as follows:
May 11, 2011 ETMX replaced, life time 1,258 days or 3.4 years
May 13, 2014 ETMX , LT 1,098 days or 3 y
May 22, 2012 ETMY, LT 1,464 days or 4 y
Oct. 5, 2011 BS & PRM, LT 4 years, laser in place at 1,037 days or 2.8 y
Sep. 13, 2011 ITMY old 1103P & SRM diode laser replaced by 1125P ..........old He life time is not known, 1125P in place 1,059 days or 2.9 y
June 26, 2013 ITMX 622 days or 1.7 y note: we changed because of beam quality.........................laser in place 420 days or 1.2 y
Sep. 27, 2013 purchased 3 JDSU 1103P lasers, sn: P893516, P893518, P893519 ......2 spares ( also 2 spares of 1125P of 5 mW & larger body )
May 23, 2016 ITMX dead laser sn P845648 replaced after 1062 days [2.9 yrs] by 1103P, sn P859884, with output output 2.6 mW, nicely round beam quality at 15 meters.
July 27, 2016 2 new 1103P from Edmonds in: P947034 & P947039, manf. date April 2016,
South end flow bench and both clean room assembly flow benches measured zero counts for 0.3 and 0.5 micron size particales.
The counting efficiency of 0.5 micron is 100%
0.3 micron particles / cf min
0.5 micron particles / cf min
The PSL HEPA performance was measured at the center of the table with MET ONE #3
The two 40 mm apeture baffles at the ends were replaced by 50 mm one. ITM baffles with 50 mm apeture are baked ready for installation.
Green welding glass 7" x 9" shade #14 with 40 mm hole and mounting fixtures are ready to reduce scatter light on SOS
PEEK 450CA shims and U-shaped clips will keep these plates damped.
The south end door leaky weather seals replaced.
The aim is here to get some overpressure inside / outside so the lab partical count would not depend on outside condition.
Oct. 5, 2015 ETMY He/Ne replaced by 1103P, sr P919645, made Dec 2014, after 2 years
Jan. 24, 2017 ETMY He/Ne replaced by 1103P, sr P947049, made Apr 2016, after 477 hrs running hot
The ITMX oplev beam is clipping. It will be corected with locked arm
The MET#1 particle counter was moved from CES wall at ITMX to PSL enclousure south west corner at 11am.
The HEPA filter speed at the Variac was turned down to 20V from 40
This counter pumps air for 1 minute in every 20 minutes. Soft foam in bags used to minimize this shaking as it is clamped.
Our new janitor Francisco is started working in IFO room today.
Large film crews are working just out side the north west corner of the lab. They started around ~ 5:30am Do not plan on working late tonight.
ETMX sus damping restored.
C1:PSL-FSS_RMTEMP, C1:PSL-PMC_PMCTRANSPD and C1:PEM-count_temp channels are not reading since Friday
ETMX sus damping recovered. PSL enclousure is dusty at 20V rotation speed. Rainy days as outside condition.
ETMX sus damping recovered.
Note: The giant metal garbage container was moved from the south west corner of CES months ago.
The logging script is multiplying by 100 instead of 10 !
It can look back 7 days trends now. There is still no vacuum channels. I can bring back the channels through the restore directory, but there are no data.
Light bulb replaced.
Bulb went out ~10am today. Looks like the lifetime of this bulb was <100 days.
Steve: bulb is arriving next week
The ITMX oplev still clipping
Bulb replaced at day 110 We have now spare now.
Healthy BS oplev
I repeated the BS oplev spectrum today and I do not understand why it does look different. I did it as Kiwamu describes it in entry#4948 The oplev servo was left ON!
It is working today! Finally I repeated the BS spectra, that we did with Kiwamu last week
The optical levers were centered during these measurements without the reference of locked cavities. They have no reference value now.
SRM sus need some help. ITMX is showing pitch/yaw modes of the pendulum .....OSEM damping is weak?
The San Gabriel mountain has been on fire for 6 days. 144,000 acres of beautiful hillsides burned down and it's still burning. Where the fires are.
The 40m lab particle counts are more effected by next door building-gardening activity than the fire itself.
This 100 days plot shows that.
We did the following:
1, closed V1, VM1, annuloses: VASE, VASV, VABS, VAEV, VAEE and VA6
2, stop rotation of Maglev-TP1, waited to decellerate and turned off power to it
3, closed V4, stoped rotation of TP2, waited to decellerate and turned power off
4, opened VM3 to RGA that is still running
I will come in tomorrow 9-10am to restart pumping.
The folding crane was fixed and tested this morning by the NNN rigging company. Pictures will be posted by Steve in the morning.
Afterwards, the ITM-east door was installed, jam-nuts checked. No high voltage was on for the in-vac PZTs.
The annulus spaces were roughed down to 350mTorr by Roughing Pump RP1. For this operation, we removed the low flow valve from the RP1 line.
After the spaces came down to ~400 mTorr, we closed their individual valves.
Warning: The VABSSC1 and VABSSC0 valves are incorrect and misleadingly drawn on the Vacuum overview screen.
Our idea is to have a much slower pumpdown this time than the last time when we had a hurricane kick up the dust. Looks like it worked, but next time we should do only 1/2 turn.
The pumpdown started at 4 PM (2300 UTC). At 10 PM, we (Jenne, Jan, and I) opened up the RV1 valve to full open. That's the second inflection point in the plot.
The 1 Ton yellow crane support beam jammed up at Friday morning, June 25.
The 40m vertex crane has a folding I-beam support to reach targeted areas. The rotating I-beam is 8 ft long. The folding extension arm gives you another 4 ft.
The 12 ft full reach can be achieved by a straightening of the 4 ft piece. There is a spring loaded latch on the top of the I-beam that locks down when the two I-beams align.
This lock joins the two beams into one rigid support beam for the jib trolley to travel. The position of this latch is visible when standing below, albeit not very well.
To be safe it is essential that this latch is locked down fully before a load is put on the crane.
We were preparing to pump down the 40m vacuum system on Friday morning. The straight alignment of the 8 and 4 ft piece made us believe that
the support beams were locked. In reality, the latch was not locked down. The jib trolley was driven to the end of the 12 ft I-beam. The 200 lbs ITM-east door was lifted
when the 4 ft section folded 50 degrees around the pivot point. This load of door + jib-trolley + 4 ft I-beam made the support beam sag about 6 inches
The door was removed from the jib hoist with the blue Genie-lift. The sagging was reduced to ~3".
The Genie-lift platform was raised to support the sagging crane jib-trolley. The lab was closed off to ensure safety and experts were called in for consultation. It was decided to bring in professional riggers.
Halbert Brothers, Inc. rigging contractor came to the lab Tuesday morning to fix the crane. The job was to unload the I-beam with safety support below. They did a very good job.
The static deformation of I-beams sprung back to normal position. There are some deformation of the I-beam ~2 mm where the beams were jammed under load.
It is not clear if this is a new deformation or if the crane sections have always been mis-aligned by a couple of mm.
The crane was tested with 450 lbs load at 12 ft horizontal travel position. The folding of I-beams were repeatedly tested for safe operation. Its a 1 ton crane, but we tested it with 450 lbs because that's what we had on hand.
We're working on the safety upgrade of this lift to prevent similar accident from happening.
Atm 1) load testing 2007
Atm 2) jammed-sagging under ~400 lbs, horizontal
Atm.3) jammed-folded 50 degrees, vertical
Atm.4) static deformation of I-beams
Atm.5) unloading in progress with the help of two A-frames
Atm.6) it is unloaded
Atm.7-8) load testing
Atm.9) latch locked down for safe operation
Atm.9) zoom in of the crane sections misalignment
IFO pressure was 2.3 mTorr this morning,
The Maglev's foreline valve V4 was closed so P2 rose to 4 Torr. The Maglev was running fine with V1 open.
This is a good example for V1 to be closed by interlock, because at 4 Torr foreline pressure the compression ratio for hydrocarbones goes down.
V4 was closed by interlock when TP2 lost it's drypump. The drypump's AC plug was lose.
To DO: set up interlock to close V1 if P2 exceeds 1 Torr
We added C1:Vac-CC1_pressure to the alarm handler, with the minor alarm at 5e-6 torr and the major alarm at 1e-5 torr.
We swapped the PMC s/n 2677 for s/n lho006.
The table below summarizes the power levels before and after the PMC swap.
- The power into the PMC (1.67 W) was measured with Scietech bolometer before the first steering PMC mirror. The leakage through the steering mirrors was measured with Ophir power meter to be 12+8 mW. There is also a lens between the mirrors which was not measured.
- The power through the PMC was measured after the doubler pick off (105 mW), steering mirror (4 mW), and lens (not measured).
- The estimated reflection from four lens surfaces is 1-2% hence 1% uncertainty in the losses in the table.
- The beams into the PMC and on REFL PD were realigned. The beams downstream of the PMC are blocked as we did not realigned the PMC and doubler paths.
- The trans PD ND filters were removed. The VDC=1.28 V now.
- The NPRO current is 2.102 A
Atm 1 old
Atm 2 is showing the butterfly valve that closes down down the orifice at higher pressure to slow down the pumping speed.
See elog entry #2573
Seems like DTT also works now. The trick seems to be to run sudo /usr/bin/diaggui instead of just diaggui. So this is indicative of some conflict between the yum installed gds and the relic gds from our shared drive. I also have to manually change the NDS settings each time, probably there's a way to set all of this up in a more smooth way but I don't know what it is. awggui still doesn't get the correct channels, not sure where I can change the settings to fix that.
DON"T RUN DIAGGUI AS ROOT
Here is a partial list of stuff which is being packed at LLO to be shipped to CIT. The electronics ckt boards are yet to be added to this list. Will do that tomorrow.
The suggested layout of the 1Y2 Rack is shown below.
To simplify the wiring, I have largely kept demod boards with the same same LO frequency close to each other.
The Heliax cables land on the top and bottom of the of subracks. These are currently flexible plastic sheets. Steve has agreed to replace them with something more rigid. It would be good to have eight N-type connectors on the top and eight at the bottom. As demod boards occur in sets of eight per subrack. So it would be convenient if the 11 and 55 Mhz Heliax cables land on the top and the rest at the bottom. In the layout I have shown the current situation.
The LO signals to the boards come from the RF Distribution box and this is kept in the middle so that cables to both the subracks can be kept short.
The outputs of the AA filter boards from both subracks have to be connected to the SCSI Interface board with a twisted pair ribbon cable.
I restarted the frame builder in the last 15mins.
I was making a change to a DAC channel in the C1IOO model.
I realigned the PSL beam going into the MC.
The MC beam was realigned so as to maximise the power in the MC. I minimised the MC_RFPD_DCMON dial on the MC_ALIGN screen while adjusting the two zig-zag mirrors at the end of the PSL table.
c1sus has been shutdown so that the optics dont bang around. This is because the watch dogs are not working.
It seems that neither c1scx nor c1scy is working properly as their ADC counts are showing digital-zeros.
The power was turned back on at 4pm It took some time for Suresh to restart the computers. We have damping but things are not perfect yet. Auto BURTH did not work well.
When Steve and I restarted the c1iscex and c1iscey computers after the power shutdown, the models within them did not start-up automatically. I had to start them manually from a terminal in the control room.
I also tried rebooting the FB a couple of times. Did not make any difference.
Manually starting the c1x05, c1scy and c1x01, c1scx models (with the Burt Restore button ON) did not resolve the issue of zeros in the epics screens. though it did re-establish timing.
If I catch anyone putting small booties into the large bootie bin, I will make said person eat small booties.
I keep a set of new TTFSS for 40m in electronic cabinet along the North arm.
The set number is #6. It is working and has not been modified by me.
Other two sets,# 5 and #7, are kept at PSL lab.
I brought TTFSS set #7 to 40m and kept it in the electronic cabinet.
note that Q4 transistor has not been replaced back to PZT2907A yet. It's still GE82.
Q3 is now pzt3904, not PZT2222A.
We removed the curved mirror behind the AOM (ROC=0.3m) on PSL table. The mirror is now in PSL lab. See PSL:905 for more detail.
I calculated thermal noise in mode cleaner (MC) mirrors and compared it with the measured MC noise. Thermal noise won't be a significant noise source for MC.
There is an idea of using MC and a refcav to measure coating thermal noise. One laser is frequency locked to MC, another laser is locked to an 8" refcav. Then the two transmitted beams are recombined so that we can readout the frequency noise. In this case, the transmitted beam from MC is a better reference (less frequency noise) than the beam from refcav. However, we need to make sure that we understand the noise sources, for example brownian noise, thermoelastic noise in both substrates and coatings, in MC more thoroughly.
I used Rana's code for MC's technical noise sources from, svn. The same plot can be found in appendix C of his thesis. Then I added my calculation to the plot. Jenne pointed me to 40m:2984 for the spot size and the cavity length. The spot radius on MC1 and MC3 is ~ 1.5mm, and ~3.4 mm@MC2, The round trip length is ~27m, thus the frequency fluctuation due to thermal noise is lower than that of refcav by 2-3 orders of magnitude. I calculated Brownian noise in coatings, Brownian noise in substrate, Thermoelastic noise in substrate. I assumed that the coatings are SiO2/Ta2O5, quarter stacks, coatings thickness for MC1/3 = 5um, for MC2 = 8um. The code can be found in the attachment.
Total thermal noise on MC (Brownian + Thermoelastic on substrate and coatings of MC1-MC3) is plotted in dashed red. It is already below 10^-5 Hz/rtHz at ~20 Hz. This is sufficiently low compared to other noise sources. Beat signal from CTN measurement with 8" cavities is plotted in pink, the estimated coating brownian noise is plotted in a yellow strip. They are well above the measured MC noise between 100 Hz to a few kHz. Measuring coating thermal noise on 8" refcav seems plausible with this method. We can beat the two transmitted beams from IMC and refcav and readout the beat signal to extract the displacement noise of refcav. I'll discuss this with Koji if this is a good surf project.
[the internal thermal noise in the original plotted is removed and replaced with the total thermal noise plot instead]
note:I'm not sure about the current 40m MC configuration. The parameters used in this calculation are summarized in mcnoiseS2L1.m (in the svn page).
I measured the RC transmitted light signals here at the 40m. I made all connections through the PSL patch panel.
Other than two steering mirrors in front of the periscope, and the steering mirror for the RFPD which were used to steer
the beam into the cavity and the RFPD respectively, no optics are adjusted.
We re-aligned the beam into the cavity (the DC level increased from 2 V to 3.83V) (Fig2) (We could not recover the power back to what it was 90 days ago)
and the reflected beam to the center of the RFPD.
I measured the spectral density of the signal of the transmitted beam behind RefCav in both time and frequency domain.
This will be compared with the result from PSL lab later, so I can see how stable the signal should be.
I did not convert Vrms/rtHz to Hz/rtHz because I only look at the relative intensity of the transmitted beam which will be compared to the setup at PSL lab.
We care about this power fluctuation because we plan to measure
photo refractive noise on the cavity's mirros
(this is the noise caused by dn/dT in the coatings and the substrate,
the absorption from fluctuating power on the coating/mirror changes
the temperature which eventually changes the effective length of the cavity as seen by the laser.)
The plan is to modulate the power of the beam going into the cavity,
the absorption from ac part will induce frequency noise which we want to see.
Since the transmitted power of the cavity is proportional to the power inside the cavity.
Fluctuations from other factors, for example, gain setting, will limit our measurement.
That's why we are concerned about the stability of the transmitted beam and made this measurement.