ID |
Date |
Author |
Type |
Category |
Subject |
6814
|
Wed Jun 13 11:19:05 2012 |
steve | Update | SUS | IDC receptacles clamped |
The MC_ IDC 64 pin cables from sat. amplifiers to junction-interface-board towards whitening - dewhitening at the back of rack 1 X 5 are finally clamped with
All other sus cables of the same kind have the correct short latch arm to lock them in for reliable contact. |
Attachment 1: IMG_1341.JPG
|
|
6813
|
Wed Jun 13 11:10:56 2012 |
rana | Update | Green Locking | my first modescan (sort of) |
You can easily calculate whether or not the coarse readout will work by thinking about the scan resolution you need given the ADC dynamic range and the whitening filter that you use. |
6812
|
Wed Jun 13 03:03:38 2012 |
yuta | Update | Green Locking | my first modescan (sort of) |
Linear range df of the delay line technique is about df ~ c/(2D). So, the linear range for the fine signal(delay line length D=30m) is about 5 MHz.
Arm cavity FSR = c/(2L) = 3.7 MHz.
So, I think we need phase shifting to do mode scan for more than 2 FSRs by holding the arm length finely with fine servo.
For the coarse (D=1.5m), the linear range is about 100 MHz, so if we can do mode scan using coarse servo, it is OK.
In any case, I think it is nice to have linear signal with fixed slope even if we don't adjust the phase every time.
Quote: |
That sounds goofy.
With the delay line technique, you can get a linear signal over 50 MHz with no phase shifting. What is with all this I/Q stuff?
|
|
6811
|
Wed Jun 13 02:24:02 2012 |
rana | Update | Green Locking | my first modescan (sort of) |
That sounds goofy.
With the delay line technique, you can get a linear signal over 50 MHz with no phase shifting. What is with all this I/Q stuff? |
6810
|
Wed Jun 13 02:11:59 2012 |
yuta | Update | Green Locking | my first modescan (sort of) |
I stabilized Y arm length by using only I phase coarse signal from the beat(C1:ALS-BEATY_COARSE_I_ERR).
I sweeped the arm length by injecting 0.05Hz sine wave from C1:ALS_OFFSETTER2_EXC.
Below is the plot of TRY and the error signal(ideally, Y arm length) while the sweep.

I couldn't hold the arm length tight, so you can see multiple peaks close to each other.
We need to
- adjust offsets
- adjust rotation phase of I-Q mixing
- adjust servo filters
to hold the length tighter.
Also, I couldn't sweep the Y arm length very much. I need to calibrate, but to do the modescan for many FSRs, we need to
- introduce automatic phase optimizing system
There were sin/cos function in the CDS_PARTS, so I think we can feedback I_ERR to control rotation phase of I-Q mixing. |
6809
|
Tue Jun 12 23:18:18 2012 |
yuta | Update | Green Locking | I-Q signals for the beat |
[Mengyao, Yuta]
Yes!! We have I-Q signals for the beat!!
What we did:
1. Aligned Y arm to the Y end green incident beam. The transmission to the PSL was about 195 uW.
2. Aligned IR beam to the Y arm by adjusting PZTs and got the transmission, C1:LSC-TRY_OUT ~ 0.86.
3. Aligned green optics on the PSL table to get the beat signal. The beat was found when;
PSL laser temperature on display: 31.41 deg C
C1:PSL-FSS_SLOWDC = 1.43
Y end laser "T+": 34.049 deg C
Y end laser "ADJ": 0
Y end laser measured temperature: 34.14 deg C
C1:GCY-SLOW_SERVO2_OFFSET = 29950
Y end slow servo: off (was on)
4. Connected the beat PD output to the beatbox.
5. Kicked ETMY position to change the cavity length and while the ringdown, we run pynds to get data. We plotted C1:ALS-BEATY_FINE_I_ERR vs C1:ALS-BEATY_FINE_Q_ERR, and C1:ALS-BEATY_COARSE_I_ERR vs C1:ALS-BEATY_COARSE_Q_ERR (below). We got nice circle as expected.
 
Current setup:
Only AA filers are put between the output of the beatbox and the ADC.
 |
6808
|
Tue Jun 12 20:35:46 2012 |
yuta | Update | Green Locking | c1gcv recompiled |
[Jamie, Yuta]
We recompiled c1gcv because the order of the channels were confusing. We found some change in the phase rotation module when we did this.
I did some cabling and checked each signals are actually going to the right channel. I labeled all the cables I know, which go into the AA chasis for ADC1 of c1ioo machine.
Below is the list of the channels. If you know anything about "unknown" channels, please let me know.
Current channel assignments for ADC1 of c1ioo machine:
Red ones were added today. Green ones existed in the past, but channel assignment were changed.
cable
|
# on AA chassis |
name in Simulink |
channel name |
connected
but unknown
|
J1A |
|
|
|
|
not connected |
J1B |
|
|
|
|
not connected |
J2 |
adc_1_2 |
C1:ALS-XARM_BEAT_DC |
not connected |
adc_1_3 |
C1:ALS-YARM_BEAT_DC |
connected
but unknown |
J3 |
|
|
|
|
connected
but unknown |
J4 |
|
|
|
|
connected
but unknown |
J5 |
|
|
|
|
connected
but unknown |
J6 |
|
|
|
|
connected
but unknown |
J7 |
|
|
|
|
beat Y arm fine I |
J8A |
adc_1_14 |
C1:ALS-BEATY_FINE_I |
beat Y arm fine Q |
adc_1_15 |
C1:ALS-BEATY_FINE_Q |
not connected |
J8B |
|
|
|
|
connected
but unknown |
J9A |
|
|
|
|
not connected |
J9B |
|
|
|
|
connected
but unknown |
J10 |
|
|
|
|
connected
but unknown |
J11 |
|
|
|
|
not connected |
J12 |
adc_1_22 |
C1:ALS-BEATX_COARSE_I |
not connected |
adc_1_23 |
C1:ALS-BEATX_COARSE_Q |
not connected |
J13 |
adc_1_24 |
C1:ALS-BEATX_FINE_I |
not connected |
adc_1_25 |
C1:ALS-BEATX_FINE_Q |
beat Y arm coarse I
|
J14 |
adc_1_26 |
C1:ALS-BEATY_COARSE_I |
beat Y arm coarse Q |
adc_1_27 |
C1:ALS-BEATY_COARSE_Q |
not connected |
J15 |
adc_1_28 |
Broken! Don't use this!! |
adc_1_29 |
(not broken) |
not connected |
J16A |
adc_1_30 |
(not broken) |
adc_1_31 |
Broken? Funny signal. |
not connected |
J16B |
|
|
|
|
Memorandum for me:
Recompiling procedure;
ssh c1ioo
rtcds make c1gcv
rtcds install c1gcv
rtcds start c1gcv |
Attachment 1: c1gcv20120612-2.png
|
|
6807
|
Tue Jun 12 17:46:09 2012 |
Jenne | Update | Computers | rtcds: command found |
Quote: |
Quote: |
We can't compile any changes to the LSC or the GCV models since Jamie's new script / program isn't found. I don't know where it is (I can't find it either), so I can't do the compiling by hand, or point explicitly to the script. The old way of compiling models in the wiki is obsolete, and didn't work :(
|
Sorry about that. I had modified the path environment that pointed to the rtcds util. The rtcds util is now in /opt/rtcds/caltech/c1/scripts/rtcds, which is in the path. Starting a new shell should make it available again.
|
Added TRX and TRY and POY11_I_ERR and POX11_I_ERR to the c1lsc.mdl using a new-style DAQ Channels block, recompiled, installed, started the model, all good. Restarted the daqd on the framebuilder, and everything is green. I can go back and get recorded data using dataviewer (for the last few minutes since I started fb), so it all looks good.
Note on the new DAQ Channels block: Put the text block (from CDS_PARTS) at the same level as the channel you want to save, and name it exactly as it is in the model. The code-generator will add the _DQ for you. i.e. if you define a channel "TRY_OUT_DQ" in the lsc model, you'll end up with a channel "C1:LSC-TRY_OUT_DQ_DQ". |
6806
|
Tue Jun 12 17:29:28 2012 |
Den | Update | CDS | dq channels |
All PEM and IOO DQ channels disappeared. These channels were commented in C1???.ini files though I've uncommented them a few weeks ago. It happened after these models were rebuild, C1???.ini files also changed. Why?
I added the channels back. mx_stream died on c1sus after I pressed DAQ reload on medm screen. For IOO model it is even worse. After pressing DAQ Reload for C1IOO model DACQ process dies on the FB and IOO machine suspends.
I rebooted IOO, restarted models and fb. Models work now, but there might be an easier way to add channels without rebooting machines and demons. |
6805
|
Tue Jun 12 17:04:55 2012 |
steve | Update | SUS | PRM oplevs servo is still bad |
Quote: |
Quote: |
Yuta claims he fixed the PRM oplev by centering it the other day, but no one has left it on and watched it for a long while, to make sure it's okay. We watched it now for ~2 min, and it was good, but we're leaving the oplevs off anyway for the night. Tomorrow we should restore PRM (it's currently restored), turn on the oplevs, and let it sit to make sure it doesn't go crazy.
|
PRM oplev servo was turned on with PITgain 0.5 and YAWgain -0.7
Note: gain settings were PIT 1.0 and YAW --0.5 on Jun 1, 2012 that I measured Feb 23, 2012
|
It is still oscillating. Gains turned down to zero. |
Attachment 1: PRMolvstillosc.png
|
|
6804
|
Tue Jun 12 16:33:32 2012 |
steve | Update | SUS | PRM oplevs servo ON for confirmation |
Quote: |
Yuta claims he fixed the PRM oplev by centering it the other day, but no one has left it on and watched it for a long while, to make sure it's okay. We watched it now for ~2 min, and it was good, but we're leaving the oplevs off anyway for the night. Tomorrow we should restore PRM (it's currently restored), turn on the oplevs, and let it sit to make sure it doesn't go crazy.
|
PRM oplev servo was turned on with PITgain 0.5 and YAWgain -0.7
Note: gain settings were PIT 1.0 and YAW --0.5 on Jun 1, 2012 that I measured Feb 23, 2012 |
6803
|
Tue Jun 12 13:49:32 2012 |
Jamie | Configuration | Computer Scripts / Programs | tconvert |
A nicer, better maintained version of tconvert is now supplied by the lalapps package. It's called lalapps_tconvert . I installed lalapps on all the workstations and aliased tconvert to point to lalapps_tconvert. |
6802
|
Tue Jun 12 11:54:50 2012 |
Jenne | Update | Green Locking | c1gcv recompiled |
Yuta added channels so we can get the Q phase of all the beat PDs to the c1gcv model. I showed him how to recompile/install/start.
During the install, it couldn't find: Unable to find the following file in CDS_MEDM_PATH: LOCKIN_FILTER.adl
On all the screens (ALS and SUS), lockin parts are white. Someone changed something, then didn't go back to fix the screens.
Otherwise, things look to be working fine. |
Attachment 1: c1gcv20120612.png
|
|
6801
|
Tue Jun 12 11:25:05 2012 |
Jamie | Update | Computers | rtcds: command not found |
Quote: |
We can't compile any changes to the LSC or the GCV models since Jamie's new script / program isn't found. I don't know where it is (I can't find it either), so I can't do the compiling by hand, or point explicitly to the script. The old way of compiling models in the wiki is obsolete, and didn't work :(
|
Sorry about that. I had modified the path environment that pointed to the rtcds util. The rtcds util is now in /opt/rtcds/caltech/c1/scripts/rtcds, which is in the path. Starting a new shell should make it available again. |
6800
|
Tue Jun 12 02:09:43 2012 |
Jenne | Update | Computers | mini boot fest |
Quote: |

|
I'm starting to feel like a wine-o here. Yuta wanted to glance at the PRM oplev dataviewer, and lo and behold, the fb lost connection just as he decided to do that. We had checked the front end status screen not 1 minute beforehand, and everything was green. Lame. |
6799
|
Tue Jun 12 02:07:42 2012 |
Jenne | Update | SUS | PRM oplevs left off |
Yuta claims he fixed the PRM oplev by centering it the other day, but no one has left it on and watched it for a long while, to make sure it's okay. We watched it now for ~2 min, and it was good, but we're leaving the oplevs off anyway for the night. Tomorrow we should restore PRM (it's currently restored), turn on the oplevs, and let it sit to make sure it doesn't go crazy.
|
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. |
6797
|
Tue Jun 12 01:03:18 2012 |
Jenne | Update | Computers | mini boot fest |
As usual, we noticed the frame builder wasn't connecting happily with the rest of the computers just as we were about to lock some stuff (we never notice it being bad when we're not trying to use the frame builder....)
All the big rectangles by each computer were white. I restarted daqd, and that brought most things back. c1lsc and c1sus needed their mx_streams restarted manually to get everything green again.

I've had about enough whine with my computers for tonight. |
6796
|
Tue Jun 12 00:15:51 2012 |
Jenne | Update | Computers | rtcds: command not found |
We can't compile any changes to the LSC or the GCV models since Jamie's new script / program isn't found. I don't know where it is (I can't find it either), so I can't do the compiling by hand, or point explicitly to the script. The old way of compiling models in the wiki is obsolete, and didn't work :(
This means we can't (a) record TRY or (b) add the Q quadrature of the beat PD to the real time system tonight.
We're going to try just using Yuta's pynds script to capture data in real time, so we can keep working for tonight. |
6795
|
Mon Jun 11 22:51:11 2012 |
Jenne | Update | Computers | tdsavg not working |
tdsavg isn't working:
controls@rossa:/opt/rtcds/caltech/c1/scripts/LSC 6$ tdsavg 10 C1:LSC-ASDC_IN1
ERROR: LDAQ - Unable to find NDS host "fb0"
ERROR: LDAQ - Unable to find NDS host "fb1"
ERROR: LDAQ - Unable to open socket to NDS.
When this command is executed inside a script, it doesn't return anything. eg:
set offset = `tdsavg 10 C1:LSC_ASDC_IN1`
echo $offset
returns a blank line.
Past elog research said lots of things about test points. I didn't suspect that, since there aren't many test points occupied (according to the CDS status screens), but I cleared the test points anyway (elog 6319). Didn't change anything, still broken.
LSCoffsets script, and any others depending on tdsavg will not work until this is fixed. |
6794
|
Mon Jun 11 21:50:08 2012 |
yuta | Update | Green Locking | beatbox looks OK |
Summary:
We need I-Q frequency deiscriminator to control the arm length fine and continuously.
I checked the beatbox (LIGO-D1102241-v4; see elog #6302) and it was working.
What I did:
1. Measured some transferfunctions with a network analyzer (Aligent 4395A) and checked the cabling is correct.
2. Put 30 m/1.5 m delay line and checked I-Q outputs are actually orthogonal. I did this by sweeping the frequency of RF input to the beatbox. See attached picture. You can see nice circle on the oscilloscope.
Some measurement results:
- Gains of the transferfunctions(@ 10-100MHz) between;
RF in -> RF mon: -25 to -20 dB
RF in -> fine delay out: -50 to -40 dB
RF in -> coarse delay out: -50 to -40 dB
RF in -> LO of mixer RMS-1: ~ +4 dB (RMS-1 needs +7 dB LO)
- 30m delay line(RG-142B/U) had -2 dB loss.
Note:
- RF input must be larger than about -3 dBm to get enough LO to the mixer. Otherwise, you won't get I-Q outputs.
- The comparator, whitening filter and differential DAQ outputs are not installed in the current beatbox.
- Current beatbox only has electronics for the one arm.
- The print on the board D1102241 says +15V and -15V, but they are actually opposite. Cabling is swapped in order to supply correct power to the ICs. |
Attachment 1: CIMG1522.JPG
|
|
6793
|
Mon Jun 11 21:35:55 2012 |
Jenne | Update | Environment | Rattling in the HEPA |
Quote: |
There is an intermittent rattling sound coming from the HEPA in the NE corner of the PSL table (right above the PMC, all of our input optics).
Steve says it might be a bad bearing, but he'll check it out in the morning and get it fixed.
|
MC was having a hard time staying locked, with no discernable reason from the control room (i.e. no big seismic, no PMC PZT railing). The HEPA was on 100%, so I turned it down to 50% to hopefully reduce the rattling, if that was what was wrong. |
6792
|
Mon Jun 11 16:08:58 2012 |
Jenne | Update | Environment | Rattling in the HEPA |
There is an intermittent rattling sound coming from the HEPA in the NE corner of the PSL table (right above the PMC, all of our input optics).
Steve says it might be a bad bearing, but he'll check it out in the morning and get it fixed. |
6791
|
Mon Jun 11 09:37:16 2012 |
steve | Update | IOO | PMC locked |
Quote: |
Quote: |
IOO Angle & IOO Position QPDs centered.
|
PMC trend of 400 and 1200 days
The Innolight 2W based PSL- IOO was implemented in the ~ summer of 2010
|
The PMC was locked and the MC followed intantly |
Attachment 1: PMClocked.png
|
|
6790
|
Fri Jun 8 15:24:08 2012 |
steve | Update | VAC | RGA scan at day 276 and pressure plots |
Quote: |
We tried not to open chambers above 10,000 particles of 0.5 micron cf/min
New items going in: 2 rasor beam traps, 5 badly oxidized old silver plated setscrew with spring loaded tips......to be replaced in the future, viton tips for eq screws....some are lose, gold plated allen wrench installed at ITMX bottom, reglued magnet on ITMX
Bad hardware things found: nylon ball "locking elements" on OSEM locking set screws with screwdriver slot, lose 1064 nm filter on OSEM pd
|
40m - pumpdown 71- maglev pumping speed - at day 276........all normal |
Attachment 1: 40m71pdM276d.png
|
|
Attachment 2: pd71m276d.png
|
|
Attachment 3: pd71d276.png
|
|
6789
|
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. |
6788
|
Thu Jun 7 18:46:13 2012 |
yuta | Update | SUS | PRM oplev centered |
PRM oplev beam was not hitting on the QPD since Jun 1, so I centered it. I reverted the oplev servo gains and now oplev servo looks fine.
C1:SUS-PRM_OLPIT_GAIN = 1.0
C1:SUS-PRM_OLYAW_GAIN = -0.7
There's SIDE to UL/UR/LL/LR coil element in PRM TO_COIL matrix. They were 0 until Mar 31, 2012, but someone changed them to -0.160. I couldn't find elog about it.
Same thing happened to BS on Mar 13, 2012 (see elog #6409), so I think somebody did the same thing to PRM. |
6787
|
Thu Jun 7 17:49:09 2012 |
Jamie | Update | CDS | c1sus in weird state, running models but unresponsive otherwise |
Somehow c1sus was in a very strange state. It was running models, but EPICS was slow to respond. We could not log into it via ssh, and we could not bring up test points. Since we didn't know what else to do we just gave it a hard reset.
Once it came it, none of the models were running. I think this is a separate problem with the model startup scripts that I need to debug. I logged on to c1sus and ran:
rtcds restart all
(which handles proper order of restarts) and everything came up fine.
Have no idea what happened there to make c1sus freeze like that. Will keep an eye out. |
6786
|
Thu Jun 7 13:25:37 2012 |
Koji | Update | SUS | PRM is still oscillating |
Done.
C1:SUS-PRM_OLPIT_GAIN 1.0 -> 0
C1:SUS-PRM_OLYAW_GAIN -0.7 -> 0
Quote: |
Set the PRM OL servo gains to zero until someone can take care of this. Turning off the buttons doesn't help anything if people run the alignment scripts.
|
|
6785
|
Thu Jun 7 13:18:42 2012 |
rana | Update | SUS | PRM is still oscillating |
Set the PRM OL servo gains to zero until someone can take care of this. Turning off the buttons doesn't help anything if people run the alignment scripts. |
6784
|
Thu Jun 7 12:49:50 2012 |
Jamie | Update | Computers | zita network configured |
Added zita to the martian host table, and configured his network accordingly:
zita A 192.168.113.217
https://wiki-40m.ligo.caltech.edu/Martian_Host_Table |
6783
|
Thu Jun 7 10:39:21 2012 |
Jamie | Update | Computers | pianosa dual monitor working |
I decided to remove what I thought was the problematic extra nVidia video card, since there are already two DVI outputs build-in. The card turned out to not even be nVidia, so I don't know what was going on there.
I futzed with the BIOS to configure the primary video card, which is some new Intel card. The lucid (10.04) support for it is lacking, but it was easy enough to pull in new drivers from the appropriate Ubuntu PPA repository:
controls@pianosa:~ 0$ sudo apt-add-repository ppa:f-hackenberger/x220-intel-mesa
controls@pianosa:~ 0$ sudo apt-add-repository ppa:glasen/intel-driver
controls@pianosa:~ 0$ sudo apt-get update
...
controls@pianosa:~ 0$ sudo apt-get upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be upgraded:
libdrm-intel1 libdrm-nouveau1 libdrm-radeon1 libdrm2 libgl1-mesa-dri libgl1-mesa-glx libglu1-mesa xserver-xorg-video-intel
8 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 3,212kB of archives.
After this operation, 25.2MB disk space will be freed.
Do you want to continue [Y/n]?
...
controls@pianosa:~ 0$
After a reboot, both monitors came up fine.
http://www.subcritical.org/running_ubuntu_lts_on_sandy_bridge/ |
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
|
|
6781
|
Thu Jun 7 08:12:20 2012 |
steve | Update | SUS | PRM is still oscillating |
Quote: |
Quote: |
What not to do:
The PRM oplev servo was left on and it was driving this oscillation overnight.
|
Oplev servo turned off and sus damping restored. What is kicking up the PRM?
|
The PRM oscillation stopped by turnig off oplev servo.
Do not turn Oplev Servo on when PRM is missaligned !
|
Attachment 1: PRMoscil.png
|
|
6780
|
Thu Jun 7 07:27:27 2012 |
Koji | Update | Green Locking | improved Y arm green alignment - even more |
Yes. The end PDH servo should be checked more carefully.
The end PDH seems to have insufficient gain at around 100Hz.
The attached is the ALS noise budget calculated with the simulink model for the green locking paper.
The residual error of the end AUX laser (green) is contributing to the final ALS signal (black).
In particular, the residual AUX frequency noise, which is shown as the blue, is contributing to the noise above 100Hz.
In the model I also confirmed that the servo still has a room for improvement.
By having more suppression of the AUX frequency noise, we will be able to increase the ALS servo bandwidth
without increasing the ALS residual RMS by a servo bump. This will give us the improvement of the seismic
noise suppression at 10Hz (i.e. more suppression of red). |
Attachment 1: freq_noise_AUX.pdf
|
|
6779
|
Thu Jun 7 05:39:41 2012 |
yuta | Update | Green Locking | coarsely stabilized Y arm length with ALS |
I coarsely stabilized Y arm length to off resonance point for IR using ALS.
Currently, ASL servo loop is unstable and oscillates so much that I can't hold the length to the resonance point.
We need more investigation on the servo loop before doing the mode scan.
Below is a snapshot of ALS medm screens and time series data of the error signal for ALS coarse loop (C1:ALS-BEATY_COARSE_I_ERR) and IR transmission for the Y arm (C1:LSC-TRY_OUT) when I turned the servo on.

Note:
I took off amplifiers right after the beat PD on PSL table.
Also, I reverted the gain change Jenne made last night (elog #6750), because they no longer show overload lights. |
6778
|
Thu Jun 7 03:37:26 2012 |
yuta | Update | CDS | mx_stream restarted on c1lsc, c1ioo |
c1lsc and c1ioo computers had FB net statuses all red. So, I restarted mx_stream on each computer.
ssh controls@c1lsc
sudo /etc/init.d/mx_stream restart
|
6777
|
Thu Jun 7 02:59:31 2012 |
yuta | Update | Green Locking | Y green beat - found it!! |
Summary:
I found the big green beat note for the Y arm. The alignment of the green optics on the PSL table was crappy.
What I did:
1. By adjusting PSL laser temperature, I found tiny beat note when
PSL laser temperature on display: 31.35 deg C (PSL HEPA 100%)
C1:PSL-FSS_SLOWDC = 1.75
and
PSL laser temperature on display: 33.21 deg C (PSL HEPA 100%)
C1:PSL-FSS_SLOWDC = -6.82
Y end laser temperature settings are fixed as follows during the measurement.
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
Bryan's formula (swapped one; see elog #6746), suggests the paring
(Yend laser temp, PSL laser temp) = (34.13 deg C, 31.09 deg C).
2. Checked that beat PD is working by swapping the beat PDs for Y arm and X arm.
3. Checked that the mode-matching of the two beams, one from Y arm and the other from PSL, is OK by moving mode-matching lens and measuring the beam spot size at near/far field are the same.
4. When checking the beam spot size at far field(~ 1 m from the BS), I noticed the relative beam tilt by ~ 1 mrad. We aligned them few days ago, but I think the green beam from the Y arm has shifted. Of course we align IR to the Y arm first, but we difinitely need dither servo or A2L for the arm, too.
5. As soon as aligning the PSL green optics near the BS, I found a large beat note. The measured amplitude was ~ -26 dBm, without any amplifiers after the PD.
Currently the measured green beam power onto the beat PD from Y end is 75 uW and from PSL is 92 uW. So the calculated beat amplitude will be ~ -10 dBm (see calculation in elog #6746). So there is about 84% loss. Anyway, I will go on to the mode scan. |
6776
|
Thu Jun 7 02:25:27 2012 |
yuta | Update | Green Locking | improved Y arm green alignment - even more |
[Koji, Yuta]
Summary:
We improved the Y arm green transmission to the PSL table. It is now 197 uW.
The improvement was done mainly by adjusting the Y arm green servo gain.
What we did:
1. Fine-adjusted steering mirrors after the faraday on Y end table by monitoring Y arm green transmission (used Thorlabs PDA36A as a PD, C1:GCV-GREEN_TRY as a channel). We decided which way to adjust the mirrors by just pushing/pulling its mount.
2. The output of the reflection PD on the oscilloscope seemed like the Y end frequency servo was oscillating. So, we reduced the amplitude of the frequency modulation from 2.83 V to 0.13 V.
3. We noticed there were two TEM00, one is brighter and the other is dim. We thought this came from a mode-hopping or something. So, we changed the Y end laser temperature from 34.68 deg C to 34.13 deg C (measured). This reduced dim TEM00 and the main one got brighter. C1:GCY-SLOW_SERVO2_OFFSET was changed from 29425 to 29845.
4. Fine-adjusted the position of the mode-matching lens by reduing LG modes.
Current green power:
Current measured green power values are as follows.

Calculated value for the Y arm green transmission is ~ 600 uW, but we think we are almost at the maximum we can get. So, we have about 70% loss from the Y end table to the PSL table. There may be large loss in windows. The beam shape of the transmitted beam seems OK, but there may be some clipping.
To do:
- Fine tune the Y end frequency servo loop. Reducing the amplitude of the frequency modulation for reducing the gain is not a very good idea. |
6775
|
Thu Jun 7 01:46:05 2012 |
yuta | Summary | Green Locking | Y green beat - found it!! |
I found the big big Y green beat. Details will be posted later.
 |
6774
|
Wed Jun 6 22:25:05 2012 |
Jamie | Update | Computers | zita now running ubuntu 10.04 |
I'll finish the rest of the config to turn it into a full-fledged workstation tomorrow. |
6773
|
Wed Jun 6 22:23:53 2012 |
Jamie | Update | Computers | Failed attempt to get pianosa to support dual monitors |
I managed to get pianosa working again with just a single monitor. I'm done trying to configure it for dual, though. |
6772
|
Wed Jun 6 22:04:19 2012 |
Jamie | Update | Computers | Failed attempt to get pianosa to support dual monitors |
I've spent an inordinate amount of time trying to figure out how to get pianosa to support dual monitors. It apparently has some special nvidia graphics that are not well supported in Ubuntu (10.04 at least). I've tried installing a newer kernel (3.0.0) and installing the special nvidia compile-from-source Ubuntu packages, but nothing is working. And now unfortunately he's not giving me any video at all. I'm sick of this today, so I'll try again tomorrow.
In the future we should avoid these bullshit nvidia cards like the plague. |
6771
|
Wed Jun 6 21:11:45 2012 |
yuta | Update | Green Locking | improved Y arm green alignment |
Summary:
Y arm green transmission to the PSL table improved from ~ 20 uW to 61 uW. Improvement was done by adjusting steering mirrors before and after the faraday on the Y end table.
But 61 uW is not enough!
What I did:
1. The incident power to the faraday for the green beam on the Y end table was 1.4 mW, but the transmission was 1.2 mW. So, I adjusted the steering mirrors and the transmission increased to 1.4 mW.
2. I found that adjusting the steering mirrors to the faraday also increased alignment of the green beam to the Y arm. We always adjusted only the steering mirrors after the faraday for the alignment. I adjusted the alignment using both steering mirrors this time. Reflection of the green beam on the ETMYT camera seems more reasonable now and more frequently lock to TEM00 when closing and opening the Y end green servo loop.
3. For the adjustment, I tried to utilize PD at the reflection port, or the transmission port. However, I couldn't do that because they fluctuates too much. I don't know why.
4. Measured the green transmission to the PSL table, The transmitted power was ~20 uW, but after the aligning, it improved to 61 uW.
Current green power:
I measured the green beam power at various places using Newport power meter (Model 840) with its filter on.

Incident green power to the Y arm is ~ 1 mW (more than 1 mW because the aparture of the power meter was smaller than the beam size) and Y arm transmission is designed to be 55%. So, if the alignment and mode matching are perfect, the transmission to the PSL table should be ~ 600 uW. The measured value 61 uW seems too small. Kiwamu says it was 140 uW when he did Y arm.
Next:
I will find the beat note again tonight and check if the beat PD is working correctly and if the mode matching of the two beams at the PSL table is good. |
6770
|
Wed Jun 6 19:46:46 2012 |
Suresh | Summary | IOO | Tip-tilt assembly: current status and work remaining |
Recent History
The lower blades which I had given to the Physics Workshop for making a vacuum relief hole (using a sinker-EDM process) came back about ten days ago. Merih Eken <meken@caltech.edu>, the supervisor at the Physics Dept workshop, handled this matter for us. The blades were sent to a local EDM machineshop and returned in about three working days ( a weekend intervened).

Bob cleaned and handed them over to me yesterday evening.
Current status
Today I have reassembled the four tip-tilts. I have repacked them in clean bags (double bagged) shifted them to Clean Optics Cabinet (near the ETMX chamber). The four tip-tilts are in the bottom-most shelf in the cabinet. There are also some tip-tilt spares in a separate envelope.
Note: The mirror holder is now held tightly by the eddy current dampers. This was done for safety of the wires during transportation from LHO. The eddy current damper in the front of the mirror has to be retracted to allow the mirror holder to swing free. It has be to about 1mm away from the suspended mirror holder
Work Remaining
1) We need to install the quadrapus cables. The connector placement on the BOSEM side will have some issues. It is best to loosen the BOSEM seating as well as the connector seating screws and then push the cable connector into place. Caution: when the connector seating screws on the BOSEM are loosened the flexible ckt could be damaged by the loose connector.
2) Insert the mirrors into the mirror holders and balance the suspension such that the mirror's hang vertical and do not have a large yaw offset.
3) Adjust the wire suspension point height so that the flags are in the center of the BOSEM aperture. Else they will strike against the
4) We need to adjust the position of the BOSEMs such that the shadow sensor signals are at 50%. This ensures that all the magnets hang at an appropriate distance from their respective coils.
5) To do (3) we need to set up a shadow sensor read-out set-up for one tip-tilt (four sensors)
|
Attachment 2: IMG_0687.JPG
|
|
6769
|
Wed Jun 6 18:22:52 2012 |
Jamie | Update | Computer Scripts / Programs | hacked ezca tools |
Quote: |
I didn't like this solution, so I hacked up something else. I made a new single wrapper script to handle all of the utils. It then executes the correct command based on the zeroth argument (see below).
I think moved all the binaries to give them .bin suffixes, and the made links to the new wrapper script. Now everything should work as expected, with this new retry feature.
|
Yuta and I added a feature such that it will not retry if the environment variables EZCA_NORETRY is set, e.g.
$ EZCA_NORETRY=true ezcaread FOOBAR |
6768
|
Wed Jun 6 18:04:22 2012 |
Jamie | Update | Computer Scripts / Programs | hacked ezca tools |
Quote: |
Currently, ezca tools are flakey and fails too much.
So, I hacked ezca tools just like Yoichi did in 2009 (see elog #1368).
For now,
/ligo/apps/linux-x86_64/gds-2.15.1/bin/ezcaread
/ligo/apps/linux-x86_64/gds-2.15.1/bin/ezcastep
/ligo/apps/linux-x86_64/gds-2.15.1/bin/ezcaswitch
/ligo/apps/linux-x86_64/gds-2.15.1/bin/ezcawrite
are wrapper scripts that repeats ezca stuff until it succeeds (or fails more than 5 times).
Of course, this is just a temporary solution to do tonight's work.
To stop this hack, run /users/yuta/scripts/ezhack/stophacking.cmd. To hack, run /users/yuta/scripts/ezhack/starthacking.cmd.
Original binary files are located in /ligo/apps/linux-x86_64/gds-2.15.1/bin/ezcabackup/ directory.
Wrapper scripts live in /users/yuta/scripts/ezhack directory.
I wish I could alias ezca tools to my wrapper scripts so that I don't have to touch the original files. However, alias settings doesn't work in our scripts.
Do you have any idea?
|
I didn't like this solution, so I hacked up something else. I made a new single wrapper script to handle all of the utils. It then executes the correct command based on the zeroth argument (see below).
I think moved all the binaries to give them .bin suffixes, and the made links to the new wrapper script. Now everything should work as expected, with this new retry feature.
controls@rosalba:/ligo/apps/linux-x86_64/gds-2.15.1/bin 0$ for pgm in ezcaread ezcawrite ezcaservo ezcastep ezcaswitch; do mv $pgm{,.bin}; ln ezcawrapper $pgm; done
controls@rosalba:/ligo/apps/linux-x86_64/gds-2.15.1/bin 0$ cat ezcawrapper
#!/bin/bash
retries=5
pgm="$0"
run="${pgm}.bin"
if ! [ -e "$run" ] ; then
cat <&2
This is the ezca wrapper script. It should be hardlinked in place of
the ezca commands (ezcaread, ezcawrite, etc.), and executing the
original binaries (that have been moved to *.bin) with $retries
failure retries.
EOF
exit -1
fi
if [ -z "$@" ] || [[ "$1" == '-h' ]] ; then
"$run"
exit
fi
for try in $(seq 1 "$retries") ; do
if "$run" "$@"; then
exit
else
echo "retrying ($try/$retries)..." >&2
fi
done
echo "$(basename $pgm) failed after $retries retries." >&2
exit 1
|
6767
|
Wed Jun 6 15:16:00 2012 |
yuta | Update | IOO | MC WFS offsets adjusted |
MC reflection (C1:IOO-MC_RFPD_INMON) got worse when WFS servos were on. After aligning MC optics, it will be ~0.5 but if I turned on WFS, it became ~0.8.
I measured the beam spot positions on MC optics. They seemed like the same from the measurement yesterday.
# filename MC1pit MC2pit MC3pit MC1yaw MC2yaw MC3yaw (spot positions in mm)
./dataMCdecenter/MCdecenter201206052111.dat 3.234388 4.234564 2.654212 -6.656221 -0.677541 4.506170
./dataMCdecenter/MCdecenter201206061420.dat 3.300867 4.567555 2.692971 -6.484464 -1.705443 4.423250
So, I ran /opt/rtcds/caltech/c1/scripts/MC/WFS/WFS_FilterBank_offsets to adjust the WFS offsets.
C1:IOO-MC_RFPD_INMON is now ~ 0.5 and C1:IOO-MC_TRANS_SUM is now ~ 2.7e3 with WFS on. |
6766
|
Wed Jun 6 14:36:58 2012 |
steve | Update | SUS | ETMY oplev work finished |
Quote: |
Quote: |
Quote: |
The typical sign of a dying gas laser is that it glows for a few minutes only. The power supplies are fine.
Two new JDS - Uniphase 1103P lasers ( NT64-104 ) arriving on Monday, May 21
|
Yesterday I swapped in new He/Ne laser with output power 3.5 mW The return spot on qpd is large ~6mm in diameter and 20,500 counts
The spot size reduction require similar layout as ETMX oplev.
|
The oplev path is relayed and the spot size on the qpd is reduced. I still have to clean up and replace "Miki Mouse" lens holder.
|
Late entry for Monday morning June 4, 2012
Cables were stress relieved. Cable entry - exit ports enlarged. Air gaps were minimized. |
6765
|
Wed Jun 6 14:17:56 2012 |
steve | Update | Computers | iMac ordered |
Rana, Steve,
- Part number: Z0M6
Configuration
- 2.7GHz Quad-Core Intel Core i5
- 16GB 1333MHz DDR3 SDRAM - 4x4GB
- 1TB Serial ATA Drive
- AMD Radeon HD 6770M 512MB GDDR5
- Apple Mouse
- Apple Keyboard with Numeric Keypad (English) & User's Guide
- Accessory Kit
|