Valera and I placed F 572.7 mm lens ~15 cm away from the ang qpd (in the same mount with ND filter) so that two qpds see different combination of ang and pos motion - there was no lenses prior to this change. The beam diameter is reduced to ~half .
I found that a He-Ne laser which has been used for ETMX_OPLEV was NOT giving the light.
Since I didn't find the switch key for it I have no idea if the laser is simply off or dead.
The dead laser was replaced by new JDSU 1103P of 2.6mW. The return beam is big ~5 mm diameter of 0.3 mW, 1400 counts
The SRM qpd cable was removed from the BS-table. It's path was changed from 1x4 to ITMY-table following the inner cable tray.
Laser diode oplev SRM is working. Qpd matrix values were reset like others.
In 0.44mW, returning 0.1mW, -500 counts.
Aux- rack _1Y2 is just behind 1Y3 It contains Kepco Analoge DC power supplies for +- 5, 15 and 24V
Placing these power supplies away from the LSC rack was an effort to minimize pick up from them.
A cable for IP_POS has been disconnected at the LSC rack, 1Y2. Due to it currently no IP_POS signal shows up on the digital side.
It looks like we disconnected the cable together with some unused cables when we were cleaning up the wiring of the LSC rack.
The cable, a shielded flat-cable, is supposed to send DC power to the QPD and send the signals from the QPD to an interface board on the LSC rack.
I will check how it used to be and reconnect it.
I found the disconnected cable, but I do not see the interface board at the LSC rack
I found ITMX-ISCT and BS-ISCT ( IFO sensing-control table) not covered this morning. Please do not leave tables open.
1X1 is strain relieved in the back. I will use similar approach on the rest of the racks .
Steve pulled the top AA filter box from 1X5 which handled some of the suspensions channels. We turned off all the watchdogs before pulling it out, as well as recorded which cables were connected to which inputs.
The case is undergoing a structural modification to have the ADC adapter card which previously was loosely connected via cables, securely attached to the case.
Steve still wants to do some cabling in the rack while the box is out, and will return it this afternoon once he has finished that.
Job is done. Sus damping are back on. Cabling-strain reliefing are not finished yet at 1X5 and 1X4
LSC rack 1Y2 cables are strain relieved and labeled. Spare and/or obsolete cables are laid out on the top of the beam tube and on the outside of the rack.
The POY 110 MHZ demodboard has a very touchy position in the VME crate. Watch out for it! It has to be fixed.
1064 nm transmison were measured of 40m safety glasses as shown . Their performance did not degrade. They are as good as their labels.
ETMY's watch dogs were found tripped. They were restored.
AA filter box was removed and modified at 1Y7 today. The -5V power supply was current limited when I plugged it back in. It was removed for medical attention.
NO PEM channels available! because of this.
D68L8EX-850Hz filter chips were removed and bypassed-shorted as Rana's entry on March 17, 2006 in old elog.
This unit is still has a short somewhere.
Computar 75-12.5 zooms were installed for closer look at the resonant spots. Their alignment and focus needs more loving adjustment.
Atm 1, ITMX ( it was 10-40 mm Tamron before )
Atm 2, ITMY ( it was 12mm wide angle showing the towers before )
The PMC is losing power.
While preping 1X4 for installation of c1lsc, we removed some old VME crates that were no longer in use. This freed up lots of space in 1X4. We then moved the SUS binary IO chassis 2 and 3, which plug into the 1X4 cross-connect, from 1X5 into the newly freed space in 1X4. This makes the cable run from these modules to the cross connect much cleaner.
Are we keeping these?
- I was investigating the SUS whitening issue.
- I could not find any suspension which can handle the input whitening switch correctly.
- I went to 1X5 rack and found that both of the two binary output boxes were turned off.
As far as I know they are pulling up the lines which are switched by the open collector outputs.
- I tried to turn on the switch. Immediately I noticed the power lamps did not work. So I need an isolated setup to investigate the situation.
- The cables are labelled. I will ask steve to remove the boxes from the rack.
I shut down damping to the Vertex optics and removed Binary IO Adapter chassy BO0 and BO1
About a week ago I discussed the BO0's power indicator lights with Kiwamu. They were not on or they were blinking on-off.
I put screws into ps connectors in the back, but it did not helped.
ITMY sus damping restored.
ETMX sus damping restored
Put the serial numbers into the elog. So we can identify the laser and controller in the future.
The old days the NPRO ( inside the MOPA ) was running ~1.7A 500 mW
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].
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"