ID |
Date |
Author |
Type |
Category |
Subject |
7067
|
Wed Aug 1 11:50:49 2012 |
Jamie | Update | CDS | added input monitors to LSC_TRIGGER library part |
I added an EPICS monitor to the input of the LSC_TRIGGER part, to allow monitoring the signal used for the trigger. I then added the monitors to the C1LSC_TRIG_MTRX screen (see below). This should hopefully aid in setting the trigger levels. |
Attachment 1: trigmtrx.png
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4019
|
Tue Dec 7 12:12:40 2010 |
kiwamu | Update | CDS | added some more DAQ channels |
[Joe and Kiwamu]
We added some more DAQ channels on c1sus.
We wanted to try diagonalizing the input matrices of the ITMX OSEMs because the motion of ITMX looked noisier than the others
So for this purpose we tried adding DAQ channels so that we can take spectra anytime.
After some debugging, now they are happily running.
(DAQ activation code)
There is a code which activates DAQ channels written by Yuta in this October.
/cvs/cds/rtcds/caltech/c1/chans/daq/activateDAQ.py
If you just execute this code, it is supposed to activate the DAQ channels automatically by editing C1AAA.ini files.
However there were some small bugs in the code, so we fixed them.
Now the code seems fine.
(reboot fb DAQ process)
When new DAQ channels are added, one has to reboot the DAQ process running on fb.
To do this, log in to a certain port on fb,
telnet fb 8088
shutdown
Then the process will automatically recover by itself.
After doing the above reboo job, we found tpman on C1IOO got down.
We don't fully understand why only C1IOO was affected, but anyway rebooting of the c1ioo front end machine fixed the problem.
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14255
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Mon Oct 15 12:52:54 2018 |
yuki | Update | Computer Scripts / Programs | additional comments |
Quote: |
but there's one weirdness: It get's the channel offset wrong. However this doesn't matter in our measurement because we're subtracting the dark level, which sees the same (wrong) offset.
|
When you do this measurement with oscilloscope, take care two things:
- set y-range of scope as to every signal fits in display: otherwise the data sent from scope would be saturated.
- set y-position of scope to the center and don't change it; otherwise some offset would be on the data.
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6941
|
Mon Jul 9 05:02:58 2012 |
yuta | Update | Locking | adjusted ALS filters, current RMS |
I adjusted filters of ALS to give more phase margin.
RMS of stabilized X/Y arm length is 97 pm and 65 pm respectively.
X arm ALS:
- Openloop transfer function
UGF ~160 Hz, phase margin 30 deg
1600 usec delay (LSC-XARM had 1800 usec delay) 500 usec delay (LSC-XARM had 570 usec delay) - Edited by Yuta on July 9

- Arm length spectra
Red is the free run spectrum. Measured using C1:ALS-BEATX_FINE_PHASE_OUT. Calibration factor is 1.32 nm/deg.
Green is the out-of-loop spectrum. Measured using C1:LSC-POX11_I_ERR. Calibration factor is 3.8e12 counts/m.
Blue is the in-loop spectrum. Measured using C1:ALS-BEATX_FINE_PHASE_OUT.
Black is the expected spectrum from openloop transfer function, such as (free run)/|1+G|.

Out-of-loop estimation of RMS during X ALS is 97 pm.
RMS mostly comes from 1 Hz and 3.3 Hz peak.
Out-of-loop and in-loop agrees at around 10-20 Hz.
Y arm ALS:
- Openloop transfer function
UGF ~130 Hz, phase margin 20 deg
2400 usec delay (LSC-XARM had 1800 usec delay) 760 usec delay (LSC-XARM had 570 usec delay) - Edited by Yuta on July 9

- Arm length spectra
Red is the free run spectrum. Measured using C1:ALS-BEATY_FINE_PHASE_OUT. Calibration factor is 1.30 nm/deg.
Green is the out-of-loop spectrum. Measured using C1:LSC-POY11_I_ERR. Calibration factor is 1.4e12 counts/m.
Blue is the in-loop spectrum. Measured using C1:ALS-BEATY_FINE_PHASE_OUT.
Black is the expected spectrum from openloop transferfunction, such as (free run)/|1+G|.

Out-of-loop estimation of RMS during X ALS is 65 pm.
RMS mostly comes from 1 Hz and 3.3 Hz peak.
Out-of-loop and in-loop agrees at around 3-40 Hz. |
2682
|
Thu Mar 18 15:33:17 2010 |
kiwamu | Summary | Electronics | advantege of our triple resonant EOM |
In this LVC meeting I discussed about triple resonant EOMs with Volker who was a main person of development of triple resonant EOMs at University of Florida.
Actually his EOM had been already installed at the sites. But the technique to make a triple resonance is different from ours.
They applied three electrodes onto a crystal instead of one as our EOM, and put three different frequencies on each electrode.
For our EOM, we put three frequencies on one electrode. You can see the difference in the attached figure. The left figure represents our EOM and the right is Volker's.
Then the question is; which can achieve better modulation efficiency ?
Volker and I talked about it and maybe found an answer,
We believe our EOM can be potentially better because we use full length of the EO crystal.
This is based on the fact that the modulation depth is proportional to the length where a voltage is applied onto.
The people in University of Florida just used one of three separated parts of the crystal for each frequency. |
Attachment 1: electrode.png
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2683
|
Thu Mar 18 19:00:04 2010 |
Koji | Summary | Electronics | advantege of our triple resonant EOM |
Did you find what is the merit of their impedance matching technique?
Quote: |
In this LVC meeting I discussed about triple resonant EOMs with Volker who was a main person of development of triple resonant EOMs at University of Florida.
Actually his EOM had been already installed at the sites. But the technique to make a triple resonance is different from ours.
They applied three electrodes onto a crystal instead of one as our EOM, and put three different frequencies on each electrode.
For our EOM, we put three frequencies on one electrode. You can see the difference in the attached figure. The left figure represents our EOM and the right is Volker's.
Then the question is; which can achieve better modulation efficiency ?
Volker and I talked about it and maybe found an answer,
We believe our EOM can be potentially better because we use full length of the EO crystal.
This is based on the fact that the modulation depth is proportional to the length where a voltage is applied onto.
The people in University of Florida just used one of three separated parts of the crystal for each frequency.
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|
9343
|
Tue Nov 5 08:44:21 2013 |
Steve | Update | IOO | after last steering mirror mount swap |
The IOO Angle and IOO Position qpds were recentered after this entry.
Suggested corrections in elog entry #9323 are completed:
1, last steering mirror mount replaced by Polanski mount
2, PSL output shutter mount reconfigured
IOO qpds are not centered. I failed to connect laptops to 40MARSian network. |
Attachment 1: after_Shutter_SMm_installed.png
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Attachment 2: afterlastSMmountswap.jpg
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11705
|
Wed Oct 21 10:03:15 2015 |
Steve | Update | VAC | after running out of N2 |
Quote: |
[ericq, Gautam, Steve]
Following roughly the same procedure as ELOG 11354, c1vac1 and c1vac2 were rebooted. The symptoms were identical to the situation in that ELOG; c1vac1 could be pinged and telneted to, but c1vac2 was totally unresponsive.
The only change in the linked procedure was that we did not shut down the maglev. Since I unwittingly had it running for days without V4 open while Steve was away, we now know that it can handle shorter periods of time than that...
Upon reboot, many channels were readable again, unfortunately the channels for TP2 and TP3 are still blank. We were able to return to "Vacuum normal state," but because of unknowned communication problems with VM1's interlock, we can't open VM1 for the RGA. Instead we opened VM2 to expose the RGA to the main IFO volumn, but this isn't part of the "Normal" state definite, so things currently read "Undefined state".
|
Precondition:
1, Pressure gauges had no communication ( NO COMM ) with c1vac2
2, Lost N2 supply on Oct 9 This triggered a normal all valve closed condition. At this point you replace N2 cylinders and manually swich valves to recreate VAC NORMAL configuration in the correct sequential order.
The very last thing you do is open V1 gate valve.
a, check TP2 that is the forepump of the Maglev. Foreline pressure to drypump ~ 10- 100 mTorr, rotation speed 50 Krpm
b, open V4 if P2 <1Torr
c, check Maglev rotating at 560 Hz
d, open V1 if P1 <500 mTorr
e, check TP3 foreline, rotation speed and open V5 if P3 <1 Torr with VA6 closed
f, open VA6 if PAN <1 Torr
g, open annulos valves one by one , like VASE if PASE <1 Torr and so on...........Now the Current State: should read Vac Normal
3, Maglev run for 7 days with V4 closed. This encreased its foreline pressure to estimated few Torrs and its body temp rose ~30C on the outside.
So it was sweating and it may be back streamed.
The present RGA data is indicating that it had to be very mild.
The RGA will have better sensitivity with VM1 open and VM2 closed.
The PSL output shutter stayed open during these period is pointing to IFO pressure stayed P1 <3 mTorr
PROBLEM: P1 and P2 plot should show nothing where there is no communication.http://nodus.ligo.caltech.edu:8080/40m/151016_182003/oct16Fpm2015.png
How do we check if pressure based software interlocks are working in this no communication condition? |
Attachment 1: 1d_after_reboot.png
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2156
|
Wed Oct 28 14:39:10 2009 |
steve | Update | PEM | after the tour of the 40m |
Illuminators and PSL lights turned off.
HEPA filter speed increased from 20 to 100% |
11259
|
Mon Apr 27 09:09:15 2015 |
Steve | Update | PEM | air cond filters checked |
Quote: |
Quote: |
Yesterday morning was dusty. I wonder why?
The PRM sus damping was restored this morning.
|
Yesterday afternoon at 4 the dust count peaked 70,000 counts
Manasa's alergy was bad at the X-end yesterday. What is going on?
There was no wind and CES neighbors did not do anything.
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Air cond filters checked by Chris. The 400 days plot show 3 bad peaks at 1-20, 2-5 & 2-19 |
Attachment 1: 400d.png
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13895
|
Tue May 29 16:33:04 2018 |
Steve | Update | PEM | air cond filters replaced |
Chris replaced some air condition filters and ordered some replacement filter today.
Quote: |
Quote: |
Quote: |
Yesterday morning was dusty. I wonder why?
The PRM sus damping was restored this morning.
|
Yesterday afternoon at 4 the dust count peaked 70,000 counts
Manasa's alergy was bad at the X-end yesterday. What is going on?
There was no wind and CES neighbors did not do anything.
|
Air cond filters checked by Chris. The 400 days plot show 3 bad peaks at 1-20, 2-5 & 2-19
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5407
|
Wed Sep 14 15:05:52 2011 |
steve | Update | PEM | air cond maintenance |
Jeff has changed our AC filters inside the lab this morning. Now he is checking on the main filters at CES. He will finish the roof units tomorrow.
Met One #1 counter is on the top of IOO chamber. It is measuring 1 and 0.5 micron size particles. One year of lab condition plot below.
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Attachment 1: ac1y.jpg
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6754
|
Tue Jun 5 14:17:14 2012 |
steve | Update | PEM | air cond maintenance |
Air conditioning maintenance is scheduled for tomorrow from 8 to 11am |
6782
|
Thu Jun 7 09:52:05 2012 |
steve | Update | PEM | air cond maintenance |
Quote: |
Air conditioning maintenance is scheduled for tomorrow from 8 to 11am
|
Jeff checked and replaced filters as needed. Job completed this morning. |
Attachment 1: PEM800d.png
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10773
|
Wed Dec 10 14:26:13 2014 |
steve | Update | PEM | air cond maintenance and particle plot |
Quote: |
AC maintenance is scheduled from 8am till 11am tomorrow morning.
|
IFO air condition maintenance will continue tomorrow morning and it should be finished by 11:30AM
We have new guys taking over this job: Sal and Chris so it takes longer. The units will be shut down for a bit.
They will not enter the IFO lab. The CES housed units will be worked on. |
Attachment 1: 05.png
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10761
|
Mon Dec 8 09:03:49 2014 |
steve | Update | PEM | air cond maintenance tomorrow morning |
AC maintenance is scheduled from 8am till 11am tomorrow morning. |
8314
|
Wed Mar 20 08:59:24 2013 |
Steve | Update | PEM | air cond maitenance is today |
Outside air quality at 8:30am 1.1 million of 0.5 micron particles cf / min with MET counter #2
AC unit output measured directly at the outlet of east end 6,000 and south end 3,000 of 0.5 micron particles cf / min with counter #2
Lab measurement at the top of IOOC 20K of 0.5 micron particles cf / min with MET #1
HEPA filters: 2 mobile units at the middle of the east arm at speed 100%, PSL enclosure 20% and south end flow bench are running.
The PSL, south flow bench and mobile unit (Envirco sn69406003 ) measured zero counts of 0.5 & 0.3 micron particles
Envirco HEPA filter unit sn 69406001 measured 50 particles of 0.5micron and 320 of 0.3 micron particles cf / min with counter #2
This filter will be replaced.
NOTE: inside air quality peaks we can not control. It depends on the weather and our house keeping.
When your work is particle sensitive keep your eyes on the particle counter.
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Attachment 1: 100dPEM.png
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7744
|
Mon Nov 26 10:58:20 2012 |
Steve | Update | PEM | air cond maitenance tomorrow |
Air conditioning maintenance is scheduled for tomorrow morning till noon. |
8219
|
Mon Mar 4 11:30:47 2013 |
Steve | Update | PEM | air cond problem |
The air cond is out of order at the area covered by racks 1 X 1 through 1 X 7
The arm X and Y AC units are working. |
Attachment 1: 40dAC.png
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2972
|
Mon May 24 07:53:57 2010 |
steve | Configuration | PEM | air cond. just turned ON |
IFO room temp 27.5C , Please remember to turn AC back on ! |
Attachment 1: acoff.jpg
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1347
|
Tue Mar 3 08:44:31 2009 |
steve | Update | PEM | air cond. maintenance today |
IFO room 104 air conditions will be shut down for maintenance today.
This should be finished by noon.
The temperature and particle count variation can be more than usual. |
12712
|
Fri Jan 13 14:18:28 2017 |
Steve | Update | PEM | air condition fixed |
The old control room AC has been stick in heating mode for about 2 months. It's thermostate and fan belt was finally replaced. It was calibrated and set to 71 F ( just behind 1X6 on west wall ) around 1pm.
Out belt; sad inside
at 4 pm Rana cried
It must be too tight. |
Attachment 1: PEM_120d.png
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3192
|
Mon Jul 12 10:23:51 2010 |
steve | Update | PEM | air condition maintenance is today |
The AC filters will be checked and/or replaced today. This means the AC will be off for sort periods of time. Temperature and particle count will be effected some what.
See 800 days plot |
Attachment 1: pem2y.jpg
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13046
|
Wed Jun 7 10:07:00 2017 |
Steve | Update | PEM | air condition thermostate |
The Y arm ac thermostate was calibrated after cooling water relay replacement by Mike.... yesterday. The set temp is remaind to be 70F
The east end south wall temp is reading 22C |
3297
|
Tue Jul 27 11:43:24 2010 |
steve | Update | PEM | air quality is bad today |
The lab is at 30,000 and Pasadena air is at 1.1 e+6 particles /cf min of 0.5 micron. |
Attachment 1: pemtoday.jpg
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200
|
Wed Dec 19 11:31:01 2007 |
steve | Omnistructure | PEM | aircond filter maintenance |
Jeff is working on all air condiontion units of the 40m lab
This we do every six months. |
Attachment 1: acfilters6m.jpg
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2831
|
Thu Apr 22 09:03:54 2010 |
steve | Omnistructure | PEM | aircondition can not be turned off |
Koji and I wanted to turn off the IFO-room AC so the wind would not blow on MC1-3. We could not. The switches were probably bypassed when the power transformer was replaced at the last scheduled power outage. |
3623
|
Wed Sep 29 18:28:32 2010 |
yuta | Update | Computers | aldabella connects to the wireless network |
Background:
We need laptops that connect to the wireless network to use them in the lab.
aldabella:
Dell Inspiron E1505 laptop
Broadcom Corporation BCM4311 802.11b/g WLAN (rev 01) (PCIID: 14e4:4311 (rev 01))
What I did:
1. I followed this method(Japanese!): http://www.linuxmania.jp/wireless_lan.html
Except I installed ndiswrapper-1.56 and cabextracted sp32156.exe.
http://sourceforge.net/apps/mediawiki/ndiswrapper/index.php?title=Broadcom_BCM4311
Also, I didn't run
# ndiswrapper -m
2. Then I did step #6 in here: http://nodus.ligo.caltech.edu:8080/40m/1275
Note that the hardware is eth1 instead of wlan0.
3. Added the following line to /etc/rc.d/rc.local to make ndiswrapper load on every boot:
/sbin/modprobe ndiswrapper
Result:
aldabella now connects to the wireless martian network on every boot!!
Note:
Somehow, the method that uses Broadcom official driver doesn't work.
http://wiki.centos.org/HowTos/Laptops/Wireless/Broadcom
It returns the following error when activating eth1:
Error for wireless request "Set Encode" (8B2A) :
SET failed on device eth1 ; Invalid argument.
Error for wireless request "Set Encode" (8B2A) :
SET failed on device eth1; Invalid argument.
|
3541
|
Tue Sep 7 23:49:08 2010 |
sanjit | Configuration | Computers | aldabella network configuration |
added name server 192.169.113.20 as the first entry in /etc/resolv.conf
changed the host IPs in /etc/hosts to 192.168.xxx.yyy
made:
127.0.0.1 localhost.localdomain localhost
::1 localhost6.localdomain6 localhos6
as the first two lines of /etc/hosts
/cvs/cds mounts
on ethernet, DNS look-up works without the explicit host definitions in /etc/hosts,
but those entries are needed for wifi only connection.
|
106
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Thu Nov 15 18:06:06 2007 |
tobin | Update | Computers | alex: linux1 root file system hard disk's dying |
I just noticed that Alex made an entry in the old ilog yesterday, saying: "Looks like linux1 root filesystem hard drive is about to die. The system log is full of drive seek errors. We should get a replacement IDE drive as soon as possible or else the unthinkable could happen. 40 Gb IDE hard drive will be sufficient." |
9080
|
Wed Aug 28 06:17:15 2013 |
manasa | Update | Computer Scripts / Programs | alias for MATLAB2010 |
Although Matlab 2013 has not been causing any visible trouble so far, it takes a while to startup.
I have added alias 'ml10' to bash to start Matlab 2010 from the terminal for convenience. |
3929
|
Tue Nov 16 03:33:22 2010 |
yuta | Update | IOO | aligned Faraday, beam reached SM just before PRM |
(Koji, Yuta)
We aligned the Faraday after MC and we are now ready to install PRM.
Background:
MC was roughly aligned (beam spot ~0.7mm from the actuation center).
So, we started aligning in-vac optics.
First thing to align was the Faraday after MC3.
What we did:
1. Ran A2L.py for confirmation.(Second from the last measurement point on the A2L result plot)
2. Aligned the Faraday so that MC3 trans can go through it. We moved the Faraday itself, while we didn't touch IM2.
We turned the pitch nob of the last steering mirror at PSL table in CCW slightly in order to lower the beam at the Faraday by ~1mm.
3. During the alignment, we found that the polarization of the incident beam was wrong. It should have been S but it was P.
As there is the HWP right before the EOM, Rana rotated it so as to have the correct polarization of S on the EOM and the MC.
Note that the PMC and the main interferometer are configured to have P-pol while the MC is to have S-pol.
4. Setup the video camera to monitor the entrance aperture of the Faraday. It required 4 steering mirrors to convey the image to the CCD.
5. Moved all of the OSEMs for MC1 and MC3 so that the sensor output can have roughly half of their maxima.
6. Ran A2L.py. (The last measurement point on the A2L result plot)
7. Aligned the IO optics so that the beam goes Faraday -> MMT1 -> MMT2 -> SM3.
Result:
1. OSEM sensor outputs for MC1 and MC3 are;
(V) |
MC1 |
MC3 |
max |
current value |
max |
current value |
ULSEN |
1.3 |
0.708 |
1.37 |
0.699 |
URSEN |
1.4 |
0.845 |
1.71 |
0.796 |
LRSEN |
1.45 |
0.743 |
1.77 |
0.640 |
LLSEN |
1.56 |
0.762 |
1.56 |
0.650 |
SDSEN |
1.67 |
0.801 |
1.59 |
0.821 |
2. A2L result is;

The beam position slightly got lower(~0.2mm), because we touched SM at PSL table.
Alignment slider values changed because we moved MC1 and MC3 OSEMs.
3. Now, MC_RFPD_DCMON is ~0.39 when MC unlocked and ~0.083 when locked.
So, the visibility of MC is ~79% (for S-pol).
4. Now the incident beam to the MC has S polarization, the cavity has higher finesse. This results the increased MC trans power.
It was ~8e2 when the polarization was P, now it is ~4.2e3 when the MC is locked.
5. The beam reached SM3 at BS table. The alignment of the SM2, MMT1, MMT2 were confirmed and adjusted.
6. All pieces of the leftover pizza reached my stomach.
Plan:
- Install PRM to the BS chamber.
- Align PRM and get IFO reflection beam out to the AP table
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6713
|
Wed May 30 01:35:15 2012 |
yuta | Update | Green Locking | aligned Y arm green beam |
[Jenne, Yuta]
We aligned the Y arm for IR (C1:LSC-TRY_OUT is now ~ 0.9), and aligned the green beam from the ETMY table. The Y arm green is now resonating in TEM00 mode, but we need some monitors (green trans or green refl) to maximize the coupling.
We noticed that the MC beam spot are oscillating at ~ 1 Hz, mostly in YAW. This wasn't observable before the PMC realignment (elog #6708). We should find out why and fix it. |
6798
|
Tue Jun 12 01:58:33 2012 |
yuta | Update | Green Locking | aligned Y arm to Y end green |
[Jenne, Yuta]
We aligned Y arm to the Y end green incident beam.
We noticed two TEM00, bright and dim, so we decreased Y end laser temperature to 34.13 deg C.
It doubled the transmission of the green, and now the transmission to the PSL table is 178 uW, which is close to the maximum(197 uW) we got so far.
Current settings for Y end laser is;
Y end laser "T+": 34.049 deg C
Y end laser "ADJ": 0
Y end laser measured temperature: 34.13 deg C
C1:GCY-SLOW_SERVO2_OFFSET = 31025
Y end slow servo: on (was off)
We aligned IR beam to the Y arm by mostly adjusting PZTs and got the transmission, C1:LSC-TRY_OUT ~ 0.9.
We tried to calculate the mode-matching ratio for IR by taking TRY data while ITMY and ETMY are swinging (without ALS), but it was difficult because we see too many higher order modes.
Tomorrow, we will (1) connect the beatbox to ADC, (2) edit c1gcv model, (3) scan the arm using I-Q signals. |
1327
|
Thu Feb 19 23:50:31 2009 |
pete | Update | Locking | aligned pd's on AP table |
Yoichi, Peter
While continuing our efforts to lock, we noticed the procedure failed at a point it had gotten past last night: turning on the bounce/roll filters in MICH, PRC, and SRC. We checked the MICH transfer function and noticed that the unity gain point was ~10 Hz, well below the bounce modes. We tried increasing the gain but found saturation, and Rob suggested that there could be misalignment on the AP table, which Steve worked on today. We went out and found two of the PDs (ASDD133 and AS166) to be badly misaligned probably due to a bumped optic upstream. We re-aligned.
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4016
|
Mon Dec 6 22:18:39 2010 |
kiwamu | Update | Green Locking | aligned the beam axis |
[Suresh and Kiwamu]
We aligned the green beam to the X arm cavity more carefully.
Now the green beam is hitting the centers of ETMX, ITMX and BS.
Also we confirmed that the green beam successfully comes out from the chamber to the PSL table.
(what we did)
- opened the BS, ITMX and ETMX chambers.
- checked the positions of the beam spots on ITMX, BS and ETMX
The spot position on ETMX was fine,
But at BS and ITMX, the spots were off downward.
We decided to move the beam angle by touching a steering mirror at the end green setup.
- changed the beam axis by touching the steering mirror at the end station.
- checked the spot positions again, they all became good. It looks the errors were within ~ 1mm.
- moved the position of a TT, which is sitting behind the BS, by ~10mm, because it was almost clliping the beam.
- aligned the green optics
- got the beam coming out from the chamber.
|
7658
|
Thu Nov 1 19:28:48 2012 |
Jenne | Update | Alignment | aligned, AS beam on camera |
After everyone else did the hard work, I moved the AS first-on-the-table steering mirror sideways a bit so the AS beam is on the center of the mirror, then steered the beam through the center of the lens, onto the 2" 99% BS. I also moved the camera from it's normal place (the 1% transmitted through that BS) to the AS110 PD path, as we did last vent. We'll need to put it back before we go back to high power. |
7657
|
Thu Nov 1 19:26:09 2012 |
jamie | Update | Alignment | aligned, this time without the crying |
Jamie, Jenne, Nic, Manasa, Raji, Ayaka, Den
We basically walked through the entire alignment again, starting from the Faraday. We weren't that far off, so we didn't have to do anything too major. Here's basically the procedure we used:
- Using PZT 1 and 2 we directed the beam through the PRM aperture and through an aperture in front of PR2. We also got good retro-reflection from PRM (with PRM free-hanging). This completely determined our input pointing, and once it was done we DID NOT TOUCH the PZT mirrors any more.
- The beam was fortunately still centered on PR2, so we didn't touch PR2.
- Using PR3 we direct the beam through the BS aperture, through the ITMY aperture, and to the ETMY aperture. This was accomplished by loosening PR3 and twisting it to adjust yaw, moving it forward/backwards to adjust the beam translation, and tapping the mirror mount to affect the hysteresis to adjust pitch. Surprisingly this worked, and we were able to get the beam cleanly through the BS and Y arm apertures. Reclamped PR3.
- Adjusted ITMY biases (MEDM) to get Michelson Y arm retro-reflecting to BS.
- Adjusting BS biases (MEDM) we directed the beam through the ITMX and ETMX apertures.
- Adjusted ITMX biases (MEDM) to get Michelson X arm retro-reflecting to BS.
At this point things were looking good and we had Michelson fringes at AS. Time to align SRC. This is where things went awry yesterday. Proceeded more carefully this time:
- Loosened SR3 to adjust yaw pointing towards SRM. We were pretty far off at SRM, but we could get mostly there with just a little bit of adjustment of SR3. Got beam centered in yaw on SR2.
- Loosened and adjusted SR2 to get beam centered in yaw on SRM.
- Once we were centered on SR3, SR2, and SRM reclamped SR2/SR3.
- Pitch adjustment was the same stupid stupid jabbing at SR2/3 to get the hysteresis to stick at an acceptable place.**
- Looked at retro-reflection from SRM. We were off in yaw. We decided to adjust SRM pointing, rather than go through some painful SR2/3 iterative adjustment. So unclamped SRM and adjusted him slightly in yaw to get the retro-reflection at BS.
At this point we felt good that we had the full IFO aligned. We were then able to fairly quickly get the AS beam back out on the AS table.
We took at stab at getting the REFL beam situation figured out. We confirmed that what we thought was REFL is indeed NOT REFL, although we're still not quite sure what we're seeing. Since it was getting late we decided to close up and take a stab at it tomorrow, possibly after removing the access connector.
The main tasks for tomorrow:
- Find ALL pick-off beams (POX, POY, POP) and get them out of the vacuum. We'll use
Jenne's new Suresh's old green laser pointer method to deal with POP.
- Find all OPLEV beams and make sure they're all still centered on their optics and are coming out cleanly.
- Center IPPOS and IPANG
- Find REFL and get it cleanly out.
- Do a full check of everything else to make sure there is no clipping and that everything is where we expect it to be.
Then we'll be ready to close. I don't see us putting on heavy doors tomorrow, but we should be able to get everything mostly done so that we're ready on Monday.
** Comment: I continue to have no confidence that we're going to maintain good pointing with these crappy tip-tilt folding mirrors.
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Fri Jun 8 15:08:27 2012 |
yuta | Update | Green Locking | aligned/mode-matched Y green beat setup |
Laser temperature settings for Y arm green work today are;
PSL laser temperature on display: 31.38 deg C (PSL HEPA 100%)
C1:PSL-FSS_SLOWDC = 1.68
Y end laser "T+": 34.049 deg C
Y end laser "ADJ": 0
Y end laser measured temperature: 34.13 deg C (*)
C1:GCY-SLOW_SERVO2_OFFSET = 29845
Green transmission from Y end and PSL green power on the beat PD are;
P_Y = 28 uW
P_PSL = 96 uW
P_Y decrease from its maximum we got (75 uW, see elog #6777) is because the alignment for Y arm green is decreased. I can see the decrease from the green reflection on ETMT camera, but I will leave it because we already have enough beat.
I aligned PSL optics, including the mode-matching lens to maximize the beat note. The beat note I got is about 26dBm.
The calculated value is -14 dBm, so we have about 75 % loss.
I measured the reflection from the PD window and its reflectivity was about 30%. We still have unknown 45% loss. |
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Mon Jul 20 12:35:21 2009 |
rob | Configuration | Locking | alignment biases funny |
I found the alignment biases for the PRM and the SRM in a funny state. It seemed like they had been "saved" in badly misaligned position, so the restore scripts on the IFO configure screen were not working. I've manually put them into a better alignment. |
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Wed Sep 19 09:32:24 2012 |
Steve | Update | SUS | alignment centering jig |
SOS alignment tool with ID 9.5 and 6.3 mm |
Attachment 1: IMG_1639.JPG
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Attachment 2: IMG_1651.JPG
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Sat Dec 11 00:41:55 2010 |
kiwamu | Update | IOO | alignment of IP_ANG is done |
[Jenne, Koji and Kiwamu]
We finished a coarse alignment of IP_ANG.
The beam for IP_ANG successfully reached to the ETMY chamber and is ready for the final alignment.
(Additionally we again tried looking for a resonance for TEM00 in the X arm, but we obtained only flashes of some higher order modes.)
--- what we did
* installed the steering mirrors for IP_ANG and IP_POS.
* checked PZT1 if it worked correctly or not. It was healthy.
* neutralized and realigned PZT1.
* flipped a window, which is standing before PRM, because the wedged side of the window was at wrong side.
* realigned PZT2 and checked the spot positions on the TTs.
* repositioned more carefully the TTs and aligned them to the correct angles.
* aligned the beam to the center of both the BS and ITMY by rotating the last TT.
* aligned the beam more precisely by tweaking PZT2 while looking at the spot at the Y end.
The beam is still hitting the center of ETMY.
* aligned the steering mirror for IP_ANG while looking at the spot at the Y end.
In fact IP_ANG is visible with a card.
* aligned the BS by looking at the spot on ITMX.
* covered ETMX with aluminum foil, and made a ~1cm hole on the foil as a target.
The hole was placed on the center of ETMX.
* more precisely aligned the BS by looking at the spot on the aluminum foil.
The spot was clearly visible on CCD monitor.
* aligned the ITMX by looking at a spot on the foil. The spot represented the beam reflected by ITMX back to ETMX.
* saw flashes on the foil but couldn't make it TEM00 because it was difficult to see any flashes on the surface of either ETMX or ITMX.
It means the flashes are visible only when the beam is hitting some scattering surface.
The mirror surface of the test masses are less lossy than that of the old test masses ??
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Tue Dec 14 01:04:23 2010 |
kiwamu | Update | SUS | alignment of ITMs and PRM done |
The alignment of the ITMs and the PRM has been done.
As a result their reflections now come out at the REFL port successfully.
The vacuum work is going on well as we scheduled at the last meeting.
(plan for tomorrow)
- installation of ETMY
- installation of OSEMs on ETMY
- alignment of the beam to the center of ETMY
- alignment of the ETMY to the beam
- final alignment of IP_ANG
- setting up the oplev for ETMY
- replace one of the steering mirrors at the RFEL path by a 0 deg mirror (see here).
- setting up POX/POY (if there are time)
(today's activity)
- aligned the PRM tower such that the reflected beam goes back to exactly the same path as that of the incoming beam.
- leveled the ITMY table because the OSEMs of ITMY had been completely out of range.
- aligned the ITMY and ITMX in order to let the reflections back to REFL.
- with a help from Osamu, we put a CCD camera, which actually had been used as OMC_T, just after the view port on the AP table.
- looking at the CCD monitor we were able to see the reflected lights from the ITMs. (In fact sensor cards didn't help looking for the lights.)
- playing with the alignment of the ITMs, we easily obtained Michelson fringes, which were also visible on the CCD monitor.
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Tue Aug 16 04:25:34 2011 |
Suresh, Kiwamu | Update | SUS | alignment of MC output to Y-arm using PZTs |
We did several things today+night. The final goal was to lock the PRC so that we could obtain the POX, POY and POP beams. However there were large number of steps to get there.
1) We moved the ITMY into its place and balanced the table
2) We then aligned the Y-arm cavity to the green beam which was set up as a reference before we moved the ETMY and ITMY to adjust the OSEMS. We had the green flashing in Y-arm
3) We checked the beam position on PR2. It was okay. This confirmed that we were ready to send the beam onto the Y arm.
4) We then roughly aligned the IR beam on ETMY where Jamie had placed an Al foil with a hole. We got the arm flashing in both IR and green.
5) We used the PZTs to make the green and IR beams co-incident and flashing in the Y arm. This completed the alignment of the IR beam into the Y-arm.
6) The IPPO (pick-off) window had to be repositioned to avoid clipping. The IPANG beam was aligned such that it exits the ETMY chamber onto the ETMY table. It can now be easily sent to the IPANG QPD.
7) Then BS was aligned to direct the IR beam into the X-arm and had the X-arm flashing. It had already been aligned to its green.
8) It was now the turn of the SRC. The beam spots on all the SRC related optics were off centered. We aligned all the optics in the AS path to get the AS beam on to the AP table.
9) The AS beam was very faint so we repositioned the AS camera to the place intended for AS11 PD, since there was a brighter beam available there.
10) We could then obtain reflections from ITMY, ITMX and PRM at the AS camera.
11) Problems:
a) ITMY osems need to be readjusted to make sure that they are in mid-range. Several are out of range and so the damping is not effective.
b) When we tried to align SRC the yaw OSEM had to be pushed to its full range. We therefore have to turn the SRM tower to get it back into range.
12) We stopped here since moving the SRM is not something to be attempted at the end of a rather long day. Kiwamu is posting a plan for the rest of the day. |
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Fri Jan 18 15:08:13 2013 |
jamie | Update | Alignment | alignment of temporary half PRC |
[jenne, jamie]
Jenne and I got the half PRC flashing. We could see flashes in the PRM and PR2 face cameras.
We took out the mirror in the REFL path on the AP that diverts the beam to the REFL RF pds so that we could get more light on the REFL camera. Added an ND filter to the REFL camera so as not to saturate. |
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Wed Nov 21 01:31:37 2012 |
Koji, Ayaka | Update | Locking | alignment on ETMX table |
Since the transmission beam on ETMXT camera seemed to be clipped, we checked the optics on ETMX table.
We aligned the lens so that it is orthogonal to the beam, then the beam shape looks fine.

Also we removed some an-used optics which were used for fiber input. |
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Sat Oct 27 23:13:12 2012 |
rana | Update | Alignment | alignment strategy |
Maybe we have already discarded this idea, but why not do the alignment without the MC?
Just lock the green beam on the Yarm and then use the transmitted beam through the ITMY to line up the PRC and the PZTs? I think our estimate is that since the differential index of refraction from 532 to 1064 nm is less than 0.01, using the green should be OK. We can do the same with the Xarm and then do a final check using the MC beam.
In this way, all of the initial alignment can be done with green and require no laser Goggles (close the shutter on the PSL NPRO face). |
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Fri May 10 18:24:29 2019 |
gautam | Update | NoiseBudget | aligoNB |
I pulled the aligoNB git repo to /ligo/GIT/aligoNB/aligoNB. There isn't a reqs.txt file in the repo so installing the dependencies on individual workstations to get this running is a bit of a pain. I found the easiest thing to do was to setup a virtual environment for the python3 stuff, this way we can run python2 for the cdsutils package (hopefully that gets updated soon). I'm setting up a C1 directory in there, plan is to budget some subsystems like Oplev, ALS for now, and develop the code for the eventual IFO locking. As a test, I ran the H1 noise budget (./aligonb H1), works, so looks like I got all the dependencies... |
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Thu Oct 11 11:57:40 2012 |
jamie | Update | CDS | all IOP models rebuild, install, restarted to reflect fixed ADC/DAC layouts |
Quote: |
As Rolf pointed out when he was here yesterday, all of our IOPs are filled with parts for ADCs and DACs that don't actually exist in the system. This was causing needless module error messages and IOP GDS screens that were full of red indicators. All the IOP models were identically stuffed with 9 ADC parts, 8 DAC parts, and 4 BO parts, even though none of the actual front end IO chassis had physical configurations even remotely like that. This was probably not causing any particular malfunctions, but it's not right nonetheless.
I went through each IOP, c1x0{1-5}, and changed them to reflect the actual physical hardware in those systems. I have committed these changes to the svn, but I haven't rebuilt the models yet. I'll need to be able to restart all models to test the changes, so I'm going to wait until we have a quiet time, probably next week.
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I finally got around to rebuilding, installing, and restarting all the IOP models. Everything went smoothly. I had to restart all the models on all the screens, but everything seemed to come back up fine. We now have many fewer dmesg error messages, and the GDS_TP screens are cleaner and don't have a bunch of needless red.
A frame builder restart was also required, due to name changes in unused (but unfortunately still needed) channels in the IOP. |
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Sat Jul 18 14:55:33 2015 |
jamie | Update | General | all front ends back up and running |
After some surgery yesterday the front ends are all back up and running:
- Eric found that one of the DAC cards in the c1sus front end was not being properly initialized (with the new RCG code). Turned out that it was an older version DAC, with a daughter board on top of a PCIe board. We suspected that there was some compatibility issue with that version of the card, so Eric pulled an unused card from c1ioo to replace the one in c1sus. That worked and now c1sus is running happily.
- Eric put the old DAC card into c1ioo, but it didn't like it and was having trouble booting. I removed the card and c1ioo came up fine on it's own.
- After all front end were back up and running, all RFM connections were dead. I tracked this down to the RFM switch being off, because the power cable was not fully seated. This probably happened when Steve was cleaning up the 1X4/5 racks. I re-powered the RFM switch and all the RFM connections came back on-line
- All receivers of Dolphin (DIS) "PCIE" IPC signals from c1ioo where throwing errors. I tracked this down to the Dolphin cable going to c1ioo being plugged in to the wrong port on the c1ioo dolphin card. I unplugged it and plugged it into the correct port, which of course caused all front end modules using dolphin to crash. Once I restarted all those models, everything is back:

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