40m surfs: Nicole Ing, Iswita Saikia and Sonali Mohapatra received 40m specific safety training today.
Access to the north side of the PSL table is blocked by the 8" beam guard. This opens the beam pathways between them.
Rod Luna picked up these computers for Larry Wallace yesterday: Dell Inspiron 530, Dell Dimension 4600 and SunBlade 1000
The PRM sus damping restored. C1:SUS-PRM_SDPD_VAR is still 20-30mV and going up. Side gain turned on. This pulled it down to 5-8 mV
Why is the side osem sensing voltage 4.4V ? It can not be higher than ~2.4V.......something is rotten in the state of Denmark?
Edit by KI:
It's because Valera increased the transimpedance gain of the PRM SIDE OSEM to match the signal level to the new ADC range (#3913 ).
The I-P curve was measured again, but this time in a lower current range of 1.0-1.9 [A].
The old days the NPRO ( inside the MOPA ) was running ~1.7A 500 mW
Lightwave Laser Head M126-1064-700 sn238, mounted on full size Al base and side heat sink on
Controller 125/126 Smart Supply sn 201M
ITMY gets new Tamron M118FM50 that has improved close focusing. It is a small fixed focal length camera so the video tube cover can be put on.
The Watec LCL-902K 1/2" ccd camera was losing it power supply voltage because of bad connection. It was replaced.
He has moved the levitation stuff for his surf student to Jan's lab in W-Bridge.
I measured the power incident on REFL11 and REFL55. Steve was concerned that it is too high. If we consider this elog the incident power levels were REFL11: 30 mW and REFL55: 87 mW. (assuming efficiency of ~ 0.8 A/W @1064nm for the C30642 PD). However, currently there is a combination of Polarising BS and Half-waveplate with which we have attenuated the power incident on the REFL PDs. We now have (with the PRM misaligned):
REFL11: Power incident = 7.60 mW ; DC out = 0.330 V => efficiency = 0.87 A/W
REFL55: Power incident = 23 mW ; DC out = 0.850 V => efficiency = 0.74 A/W
and with the PRM aligned::
REFL11: DC out = 0.35 V => 8 mW is incident
REFL55: DC out = 0.975 V => 26 mW is incident
These power levels may go up further when everything is working well.
The max rated photo-current is 100mA => max power 125mW @0.8 A/W.
What is the power level on MC_REFL_ PDs and WFS when the MC is not locked?
Our design kits are full again. They are waiting for a new brilliant PD design.
Photo diodes stored in the east arm cabinet E4: ALL PDs meet here, fast or slow......
Lightwave M126-1064-700 lasers sn415 at east end of the Y arm and sn201 at the AP table are connected individually to one each EMERGENCY LASER SHUT OFF SWITCH.
The fireworks of yesterday showing up in the lab. Pasadena out side air 6.6 million cfm for 0.3 micron particles and 1.5 million cfm for 0.5 micron size.
The PRM sus damping was restored. It's side rms motion came down from 35 to 4 mV immediately. Lab air quality is back to normal.
Please ask the owner unless it is rotten. Do not put food into garbage can inside. Take them outside so you are not inviting ants !
I found baked allen keys on the top of the clean optics cabinet. Somewhat heavy box that can come down in an earthquake on our heads.
NOTHING SHOULD GO ON THE TOP OF THE CABINETS OR RACKS except small plastic boxes that storing our clean clothing.
Alberto is visiting us from Australia. He brought some terrific presents. It is going to be very demanding task to wait for the rest of the 40m team
to return from Wales to taste coffee: PNG Peaberry of Wagonga, Monsooned Malabar of Jindebah and Signature Blue Blend of Cosmorex.
Each bottle has matched seals. They are not interchangeable.
It is critical that the solvent do not reach the rubber bulb. Practice with the pipet.
In case of solvent touching the suction bulb: do not let the solvent go back into the bottle! Remove bulb, let it dry out and rinse pipet.
It is essential that the solvent bottle must be rinsed and refilled if it's content met with the rubber bulb.
Use glass syringe with SS needle in critical application: Hamilton ~0.1 ml
The PRM watchdogs were tripped. The side was kicked up to 180mV Damping was restored.
Please return sensor card to laser log box so others can use it. We have only one larger fluorescent sensor card.
C1:SUS-ETMX_OLPIT_GAIN set to 1.0 OLYAW 1.0
ETMY -0.2 -0.2
ITMY 2.0 -2.0
ITMX 0.5 0.5
BS 0.4 -0.4
PRM 0.5 -0.7
SRM 1.0 1.0
Earlier today Rana and I made power spectra of ETMY_OPLEV_ERROR signals with servo on and off.
It was indicating that the servo is not doing anything. These gain values were not set since IFO rebuilt.
Valera's entries were searched also. He did not do such thing. Rana may know where it is in the elog if it happened.
OSEM voltages to be corrected at upcoming vent: threshold ~ 0.7-1.2V, ( at 22 out of 50 )
ITMX_UL, UR, LL, LR, SD
ETMX_UL, UR, LL, LR, SD
SRM_UL, UR, LL
MC3_UL, LR, LL
Present values agree with conlog records. It can be concluded that there were no big changes made. There are some 0.1-0.2 gain and one polarity changes during the periods of Valera's visits.
Dec 21, 2010 we pumped down the MARK4 rebuilt 40m-IFO and the malev has been pumping on it since than
[Kiwamu / Steve]
We checked some electronics noise on the ETMY shadow sensor system.
Noise from the WF, AA board and ADC are below the shadow sensor spectra on ETMY.
It means something funny is going on in the upstream side (including the satelight box and shadow sensors)
OR the coil drivers side are going crazy ??
As Rana pointed out in his entry (#5025), the spectra of the shadow sensors on ETMY were quite bad below 3 Hz. The floor are higher than that of ETMX by factor of 10 or so.
To check if the noise comes from some of the electronics, we disconnected D15-sub from pd to whitening in.
The spectra with/without shadow sensors are attached below.
The curves in brown and green are the ones taken when the shadow sensors were disconnected from the WF board.
So these two curves represent the summed noise of the WF, AA and ADC.
This tells us to look toward the OSEM.
I test drove ETMY biases.
PITCH worked well in slow and fast modes. Slow drive was from the IFO alignment screen C1:SUS-ETMY_PIT_COM and
the fast one from C1:SUS-ETMY_ASCPIT_OFFSET
YAW did not. It was always diagonal. It was specially bad with the fast drive. I compared them with ETMX. ETMX yaw is diagonal a little bit too.
The OPLEV return spots on the qpd ETMX and ETMY are big 5-6 mm diameter. The ETMY spot has weird geometry to qpd.
80 days: PMC is drifting
We have cleaned, baked, rga scaned traps for vacuum. Thorlabs LB1 on 1" OD ss posts and forks. The effective surface area is 43 x 18 mm of stacked razors.
Seven pieces are mounted on New Focus #9962 1" OD SS vented- pedestrals to 5.5" center height and 5 pieces to 4.875"
Our surf student Manuel Marchiò received 40m specific safety training today.
OSEM damping gains were adjusted by observing real time dataviewer to get Q of 5
OSEMs were kicked up one by one with 200 counts ~1sec. The error signal was optimized to get 1/2 of exitation amplitude at the 5th sinusoid wave.
C1: SUS-ITMX_SUSPOS_N1 gain 111 -> 65, PIT 7.2 -> 8, YAW 12 -> 6, SIDE 280
ITMY 277 -> 120, 19.2 -> 7, 24 -> 19, 420 -> 470
ETMY 10 -> 32, 20 -> 3, 20 -> 10, 50
ETMX 22 -> 25, 3, 3, -170
ETMX having problems: 1, YAW can not be excited
2, SIDE has no error signal in dataviewer. Sensing voltage on MEDM screen 0.142V
Jamei fixed the computer. Now I had a healthier ETMX with SIDE signal that allowed me to set gains to get Q of 5
The Y arm restore locked the arm at TRY -out 2.4V, the X arm still did not lock or align to lock. It has some fringes.
ETMX POS gain 22 -> 17, PIT 3 -> 1, YAW 3, SIDE -170 -> -110
PRM 50 -> 30, 1, 2, 50
SRM 55 -> 20, 2.4 -> 1.5, 4.8 -> 2, 140 -> 100
Now all SUS OSEM gains are set
Both arms locked easely around 1V transmited. We should recenter oplevs.
Kiwamu, Koji and Steve,
Arm aligned separatly and oplev qpds were centered including BS. Than we realigned manually DRM and centered their qpds.
ALL SUS oplevs were centered to resonating cavities.
SUS-ETMY_QPD is not responding. It is reading zero in dataviewer and 4,400 counts on QPD MEDM screen.......must be wrong cable connected
IP-POS is sick. Last time alive 7-19-2011
IP-ANG beam is clipping on pick-up mirror at ETMY chamber. This will have to be fixed at the vent. The qpd itself is responding to light.
The vacuum system is coming up to atm. The vent was started with slow N2 flow. The PSL output is blocked 2 places on the table.
ITMX watchdog tripped around 5 Torr and the PRM around 450 Torr of this vent. They were restored than.
We are at 580 Torr now.
P1 at 750 Torr, Vent valve VV1 is left open to atm. It will reach equilibrium in an hour. The PSL power is not turned down yet. The beam path is blocked at two places inside the enclosure.
The low power 20 mW input MC can be locked tonight.
Next day's - Thursday notes:
We reached 760 Torr of atm in 8 hrs at 1.7 Torr/ min with 5 cylinders of instrument grade air.
Used 500 PSI of nitrogen to get to 20 Torr at first. This flow and the first cylinder of N2 has to be slower next time.
We did the following:
1, oplevs were centered on locked caveties 2 days ago
2, just before vent we rechecked arms pointing, they wre still locking
3,eloged strain gages and turned HVs off at PZT-steering at 1Y3 rack and OMC-PZT ps at 1X2 aux rack. They were actually off.
4,,checked jam nuts 6 places x 3
5, turned oplev servos off
6, eloged SUS summery page
7, checked particle counts at ITMY: 1 micron 300, 0.5 micron 3K, 0.3 micron 30K particles / cft-min. All three cranes were wiped 2 days ago.
8, blocked laser into IFO: main 1064 in 1.25W were blocked by manual 2 blocks on PSL table. The PSL output shutter was left open to be triggered by interlock at P1 3 mTorr. It did!
Aux NPRO-AP and green light input at both ends were blocked.
ITMX and PRM moved alot. BS and ITMY just a little based on oplev reference.
We need a plan how to minimize cross coupling in the OSEMs now
The horizontal trolley drive stopped working at the east end this morning. It is working intermittently. In the worst case we can take the door off with the manual -Genie- lift.
I'm working with Konecrane to solve the wormgear drive problem.
Just a reminder that a film crew will be here Monday morning, filming Christian Ott for some Discovery channel show.
They are slated to be here from 8am to 12:30pm or so. They will take a couple of shots inside the lab, and the rest of the filming should be of Christian in the control room (which they will "clean up" and fit with "sexy lighting"). I will try to be here the whole time to oversee everything.
Konecrane Fred was early this morning. He diagnosed the ETMY crane horizontal drive gear box dead and left just before the film crew showed up.
New gear box should be here by the end of this week for installation.
The lab air quality is high ~20,000 counts of particles of 0.5 micron. Keep an eye on this before you open the chamber.
While Kiwamu was finalizing the X green alignment, I started to prepare to remove the ETMY door, and begin checking out its OSEMs, etc, so we could start moving it to it's new place, and figure out why it's been wonky for a while. I ran the particle counter, and we have a factor of ~5 more particles than normal. Kiwamu and I agreed not to open ETMY. Since we had briefly opened the IOO and Output Optics chambers to check the X green's position on the PSL table, we immediately shut those doors. They were probably open for ~15 minutes or so. (Yes Steve, we should have checked before opening any doors, but at least we remembered to check at all, and the doors were only open for a few minutes rather than for a few hours.)
I attach a 24hrs trend of the particle counts, for reference. It looks like it's been a little high for a while, but today it's really dirty in the air.
The east end particle count is 155K for 0.3 micron and 15K for 0.5 micron counts/cf min. In order to minimize diffusion of dirt into the IFO we set up the mobile HEPA with CP Stat 100 tent.
This set up gives us practically ZERO inside the tent
The RGA region is beeing monitored during the vent. This will tell us how clean the RGA itself is.
I measured the particles coming off of new- unused clean room coat. Tyvek, Convertors, Allegiance #9393 measured 10 counts of 0.3 micron at 1 minute and 0 count at 7 minute.
The 0.5 micron size measured 0 at both times. Jenne's used coat measured 20 counts of 0.3 micron and 0 counts for 0.5 micron at 1 minute. ( counts / cf- min)
The HEPA tent background is consistently 0 when it's CP STAT 100 curtains are closed.
Jenne found a big scratch on the north vac door of ITMY. Fortunately it does not reach the inner annulos 0 -ring seal.
This is precisely what we have to avoid to preserve our vacuum system!
Suresh and I tweaked the OSEM angles in ETMX yesterday. Last night the ETMs were left free swinging, and today I ran Rana's peakFit scripts on ETMX to check the input diagnolization:
It's well inverted, but the matrix elements are not great:
pit yaw pos side butt
UL 0.3466 0.4685 1.6092 0.3107 1.0428
UR 0.2630 -1.5315 1.7894 -0.0706 -1.1859
LR -1.7370 -1.5681 0.3908 -0.0964 0.9392
LL -1.6534 0.4319 0.2106 0.2849 -0.8320
SD 1.0834 -2.6676 -0.9920 1.0000 -0.1101
The magnets are all pretty well centered in the OSEMS, and we worked at rotating the OSEMS such that the bounce mode was minimized.
Rana and Koji are working on ETMY now. Maybe they'll come up with a better procedure.
I'm having this problem with DTV every morning at Rosalba only. It wants to start with a negative GPS time and it can not connect to the frame builder.
Normally after a few time of starting it, it will work.
Gear box found, it's lead time one week at $825 The crane may be functional round August 25