ID |
Date |
Author |
Type |
Category |
Subject |
3549
|
Thu Sep 9 08:23:45 2010 |
steve | Update | SAFETY | main laser turned off |
Innolight 2W 1064nm main laser was turned off for more enclosure related work.
The electrician re rooting the power- conduit to the interlock under the floor and bring it through the new concrete tunnel.
Emergency laser power shut off switch was tested at entry door 104M. It worked fine.
No laser glasses required. Laser will be turned back on around 11 am today. |
3548
|
Thu Sep 9 05:58:04 2010 |
kiwamu | Update | PSL | mode matching from PMC to IMC |
I started mode matching of the beam going to IMC. The work is still going on.
According to Rana's calculation (see here), I put the first lens (f=200mm) in between two steering mirrors after PMC.
The distance from PMC to the first lens was adjusted by using a metal ruler. So I believe the accuracy is something like 1mm.
I aligned the beam path going through the broadband EOM and the mode matching lenses.
I could find the optimum position for the second lens (f=-150mm) by sliding the position of the lens and measuring the mode after it.
But the optimum position looked a bit far from the EOM. It's off by about 3-4 inch from the designed position.
Somehow I feel that the beam before the second lens goes with a smaller divergence angle than that of designed.
So tomorrow I am going to restart the work from checking the mode before the second lens.
Maybe at first I should measure the mode without going through the EOM because it changes the waist position and makes the system not straightforward. |
3547
|
Wed Sep 8 16:17:58 2010 |
steve | Update | PEM | particle counter problem |
I played with the particle counter this morning. Now it's running and reading the correct numbers on the old COCHECKLIST.adl medm screen.
However, it can not be seen with dataviewer.
Koji just rebooted the frame builder and the problem was solved. |
3546
|
Wed Sep 8 14:44:37 2010 |
josephb | Update | CDS | Updated parse_mdl_to_ipc.py and feCodeGen.pl |
I updated parse_mdl_to_ipc.py to correctly work with the 3 new cdsIPCx parts, namely cdsIPCx_PCIE (for dolphin connections), cdsIPCx_RFM (for our traditional reflected memory connections), and cdsIPCx_SHMEM (local shared memory on the computer). These parts replaced cdsIPCx awhile back (see here ).
The code now correctly counts each type independantly with regards to ipcNum (I.e. you can have ipcNum = 0 for RFM and ipcNum = 0 for SHMEM for example).
I also went in and modified a few sections of the feCodeGen.pl (in /opt/rtcds/caltech/c1/core/advLigoRTS/src/epics/util/) so as to properly assign names to matrix adl files, matrix of filter bank adl files, and filter bank adl files. |
3545
|
Wed Sep 8 11:56:24 2010 |
kiwamu | Summary | CDS | September CDS test plan |
Joe and Kiwamu
We discussed about our CDS plan for this September. The summary of the plan and "to do list" are now on the wiki page;
http://lhocds.ligo-wa.caltech.edu:8000/40m/Upgrade_09/CDS/September_CDS_plan
Basically there are three major missions that we will do in this month;
1. complete damping of the vertex suspensions
2. Preparation for Green locking
3. Development of Simulated Plants
We also try to keep updating the wiki page. |
3544
|
Wed Sep 8 11:46:53 2010 |
kiwamu | Update | PSL | update of the layout |
I put some green stuff on the layout drawing.
I continue to refine the positions of these stuff.
Notes :
1. I flipped the reference cavity. So now the cavity is sitting on the left hand side of the layout.
2. I removed the ISS stuf. We should think about where ISS should be.
Quote: |
Also, Kiwamu has modified the layout drawing to add the green PLL stuff. This has collapsed the reference cavity's wave function placing it close to its original position.
WE (maybe Valera and Steve) can now put the reference cavity back on the table.
|
|
Attachment 1: 40mPSL.png
|
|
3543
|
Wed Sep 8 09:50:13 2010 |
rana | Update | PSL | PSL update |
Also, Kiwamu has modified the layout drawing to add the green PLL stuff. This has collapsed the reference cavity's wave function placing it close to its original position.
WE (maybe Valera and Steve) can now put the reference cavity back on the table. |
3542
|
Wed Sep 8 00:01:07 2010 |
rana, valera | Update | PSL | PMC update |
We ran the cables for the PMC: The RF cable for the 35.5 MHz drive was cheap and so we swapped the 29.5 MHz cable for it.
There now remain 1 RG-174 cable to drive the FSS PC (21.5 MHz) and 3 Heliax for the Kiwamu Tri-Mod EOM (11, 29.5, and 55 MHz).
We also changed the BLACK HV drive cable for the RED one (previously used for the MZ). All HV cables MUST be RED.
The BLACK cable is now used for the PMC_REFL DC.
The Heliax cables are routed onto the table - it remains a Alberto/Kiwamu job to strain relieve them and attach them to the TriMod box and EOM in the morning.
The PMC is locked and we did some partially bootless alignment and mode-matching. It locks easily on a TEM00 mode (with very poor visibility), but the
rest of the beam train can now be aligned while Valera does the PMC matching mambo. 
|
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.
|
3540
|
Tue Sep 7 23:34:15 2010 |
Kiwamu, Sanjit | Configuration | Computers | e-log |
e-log was repeatedly hanging and several attempts to start the daemon failed.
problem was solved after clearing the (firefox) browser cache, cookie, everything!!
|
3539
|
Tue Sep 7 23:17:45 2010 |
sanjit | Configuration | Computers | rossa notes |
Quote: |
* rossa needs to be able move windows between monitors: Xinerama?
|
Xinerama support has been enabled on rossa using nvidia-settings. |
3538
|
Tue Sep 7 22:21:47 2010 |
Dmass | Configuration | elog | elog restarted |
Quote: |
elog crashed on an upload. restarted and it worked fine with the same file.
|
Again. Resubmitted an old entry with just text changes. Elog hung for 5 min +. |
3537
|
Tue Sep 7 22:21:17 2010 |
Alberto | Configuration | Computers | elog restarted |
|
3536
|
Tue Sep 7 20:44:54 2010 |
Yoichi | HowTo | COMSOL Tips | COMSOL example for calculating mechanical transfer functions |
I added COMSOL example files to the 40m svn to demonstrate how to make transfer function measurements in COMSOL.
https://nodus.ligo.caltech.edu:30889/svn/trunk/comsol/MechanicalTF/
The directory also contains an (incomplete) explanation of the method in a PDF file. |
3535
|
Tue Sep 7 15:57:07 2010 |
Alberto | Configuration | Computers | Nodus connection not working. Fixed |
[Joe, Alberto]
The Nodus connection to the Martian network stopped working after someone switched cables on the Netgear router. Apparently that router doesn't like to have the 23 and 24 ports connected at the same time.
Joe fixed the connection just freeing either the 23 or the 24 port. |
3534
|
Tue Sep 7 15:31:28 2010 |
josephb, alex | Update | CDS | Binary Output working/ IO chassis fixed |
As noted previously, we were having problems with getting multiple 32 channel binary output cards working. Alex came by and we eventually tracked the problem down to an incorrect counter in the c code. This has been fixed and checked into the CDS svn repository. I tested the actual hardware and we are in fact able to turn our test LEDs on with multiple binary output boards.
Alex and I also looked at the non-functional IO chassis (the one which wouldn't sync with the 1PPS signal and wasn't turning on when the computer turned on. We discovered one corner of the trenton board wasn't screwed down and was in fact slightly warped. I screwed it down properly, straightening the board out in the process. After this, the IO chassis worked with a host interface board to the computer and started properly. We were able to see the boards attached as well with lspci. So that chassis looks to be in working condition now.
Onwards to the RFM test. |
3533
|
Tue Sep 7 14:42:02 2010 |
Dmass | Configuration | elog | elog restarted |
elog crashed on an upload. restarted and it worked fine with the same file. |
3532
|
Tue Sep 7 13:31:49 2010 |
Alberto | Update | Electronics | RF System - Frequency Distribution Box - Priority Plan |
We need a distribution unit in the LSC rack to: 1) collect the demod signals coming from the Frequency Generation Box 2) adjust the power level 3) generate 2nd harmonics (for POP) 4) distribute the demod signals to the single demodulation boards.
The base line plan is the following:

The box can be build up gradually, but the priority goes to these parts:

I need help for this work. I know exactly how to do it, I just don't have the time to do it all by myself.
Besides the Distribution Box, the demodulation part of the upgrade would still require two steps:
1) upgrade the Band Pass Filters of the demodulation boards (I have all the parts)
2) cabling from the distribution box to the demod board (one-afternoon kind of job) |
3531
|
Tue Sep 7 10:50:53 2010 |
josephb | Configuration | Computers | rossa notes |
The controls group is user id 500 by default on most new machines. Unfortunately, the user ID used across the already existing machines is 1001. One method of doing this switch is in this elog. You can also do the change of the controls ID by becoming root and using the graphical command system-config-users. This will let you change the user ID and group ID for controls to 1001. This graphical interface also lets you change the login shell.
Unfortunately, I had some minor difficulty and I ended up removing the old controls and creating a new controls account with the correct values and using tcsh. The .cshrc file has been recreated to source cshrc.40m. The controls account now has correct permissions, although some of the preferences such as background will need to be reset.
Quote: |
**** Deleted
apps/emacs
apps/linux64/firefoxold
apps/linux64/comsol (old v. 3.5)
* running up2date on rossa
* rossa needs to be able move windows between monitors: Xinerama?
* there are permissions problems: controls on rossa can't
make and delete directories made by 'controls' elsewhere.
Some sort of user# or group issue?
|
|
3530
|
Tue Sep 7 08:56:00 2010 |
Alberto | Update | Electronics | Frequency Generation Box Assembly - Phase Noise Measurements |
Here are the results of my phase noise measurements on the 7 outputs of the Frequency Generation Box. (BIN=95L applied by DTT). See attached pdf for a higher definition picture.

The plot shows that the phase noise of the 11 MHz outputs (Source, EOM modulation signal, Demodulation signal) is as low as that of the Marconi. The Marconi is limiting my measurement's resolution.
The mode cleaner signal's oscillator (29.5 MHz output, blue trace) is higher than the 11MHz above 1KHz.
The 55MHz signals have all the same phase noise (traces overlapped), and that is higher than the 11 MHz ones from about 100Hz up. i don't know what's going on.
I need to use the spare 11MHz Wenzel crsytal to have a better reference source for the measurement. |
Attachment 2: 2010-09-03_FreqBoxPhaseNoise_AllOutputsComparison_smooth.pdf
|
|
3529
|
Mon Sep 6 22:09:11 2010 |
Alberto | Update | Electronics | RF Frequency Generation Box heat sink installed and tested |
Last week I noticed that the high power amplifiers in the Frequency Generation Box became hot after 2 hours of continuous operation with the lid of the box closed. When I measured their temperature it was 57C, and it was still slowly increasing (~< 1K/hr).
According to the data sheet, their maximum recommended temperature is 65C. Above that their performances are not guaranteed anymore.
These amplifiers aren't properly dissipating the heat they produce since they sit on a plastic surface (Teflon), and also because their wing heat dissipator can't do much when the box is closed. I had to come up with some way to take out their heat.
The solution that I used for the voltage regulators (installing them on the back panel, guaranteeing thermal conduction but electrical isolation at the same time) wouldn't be applicable to the amplifiers.
I discussed the problem with Steve and Koji and we thought of building a heat sink that would put the amplifier in direct contact with the metal walls of the box.
After that, on Friday I've got Mike of the machine shop next door to make me this kind of L-shaped copper heat sink:

On Saturday, I completely removed the wing heat dissipator, and I only installed the copper heat sink on top of the amplifier. I used thermal paste at the interface.

I turned on the power, left the lid open and monitored the temperature again. After 2 hours the temperature of the amplifier had stabilized at 47C.
Today I added the wing dissipator too, and monitored again the temperature with the lid open. then, after a few hours, I closed the the box.
I tracked the temperature of the amplifier using the temperature sensors that I installed in the box and which I have attached to the heat sink.
I connected the box temperature output to C1:IOO-MC_DRUM1. With the calibration of the channel (32250 Counts/Volt), and Caryn's calibration of the temperature sensor (~110F/Volt - see LIGO DOC # T0900287-00-R), the trend that I measured was this:

Conclusion
The heat sink is avoiding the amplifier to overheat. The temperature is now compatible with that of the other component in the box (i.e., crystal oscilaltors, frequency multiplier).
Even with the lid closed the temperature is not too high.
Two things remain untested yet:
1) effect of adding a MICA interface sheet between the heat sink and the wall of the chassis. (necessary for gorund isolation)
2) effect of having all 3 amplifiers on at the same time
I am considering opening air circulation "gills" on the side and bottom of the chassis.
Also we might leave the box open and who ever wants can re- engineer the heat sink.
For posterity.
- Ideally we would like that the heat sink had the largest section area. A brick of metal on top the amplifier would be more effective. Although it would have added several pounds to the weight of the box.
- We need these amplifiers in order to have the capability to change the modulation depth up to 0.2, at least. The Mini-Circuit ZHL-2X-S are the only one available off-the-shelf, with a sufficiently low noise figure, and sufficiently high output power. |
3528
|
Mon Sep 6 21:08:44 2010 |
rana | Update | CDS | Susension model reviewed |
We must remember that we are using the Rev.B SOS Coil Drivers and not the Rev. A. 
The main change from A->B was the addition of the extra path for the bias inputs. These inputs were previously handled by the slow EPICS system and not a part of the front end. So we used to have a separate bias screen for these than the bias which is in the front end. The slow bias is what was used for the alignment to avoid overloading the range of the main coil driver path. |
3527
|
Mon Sep 6 20:38:58 2010 |
Koji | Update | CDS | Susension model reviewed |
I have reviewed the suspension model of C1SUS and refined it.
It is comaptible to the current one but has minor additions. |
Attachment 1: suspension_model.pdf
|
|
3526
|
Mon Sep 6 10:08:10 2010 |
Alberto | Configuration | Computers | Netgear Network Switch fan broken. |
The Netgear Network Switch in the top shelf of Nodus' rack has a broken fan. It is the one interfaced to the Martian network.
The fan must have broken and it is has now started to produce a loud noise. It's like a truck was parked in the room with the engine running.
Also the other network switch, just below the Netgear, has one of its two fans broken. It is the one interfaced with the General Computer Side.
I tried to knock them to make the noise stop, but nothing happened.
We should consider trying to fix them. Although that would mean disconnecting all the computers. |
3525
|
Mon Sep 6 01:46:58 2010 |
rana | Update | PSL | PSL update of the day |
To bypass the polarizer issue, I just used cubes. One I took from the FSS-Refcav path and the other from the power control part of the old MOPA, just downstream of the MOPA's periscope.
We'll swab these out with the thin-film polarizers after we get the mounts made.
With the cubes in, I also installed the Faraday + its 1/2-wave plate. The transmission looks good and we're getting into the PMC and its flashing a TEM00 mode sometimes. I set up a signal generator to drive the SLOW actuator by 1 FSR at 0.1 Hz.
I have set up a PMC transmission camera and transPD so that its easy to align. The flashing mode already allows us to align most of the rest of the table (except FSS).
Our next step should be to run the cables for locking the PMC:
- RF cables to the PMC_REFL
- Dsub for the PMC RFPD
- HV cable between the PMC servo board and the PMC PZT (why is this not RED? we have to make sure to abide by the cabling color code).
- RF cable from 35.5 MHz Frequency Reference card to the PMC EOM via the RF summing box on the table.
On Tuesday, we need to make sure that all of our mounts' drawings are in the cue for the shop. I'll put the list of mounts onto the PSL upgrade wiki page.
We also have to come up with a plan for wiring some of the 2W NPRO's channels into the cross-connect so that we can have some laser channels recorded by EPICS. |
3524
|
Sun Sep 5 21:35:41 2010 |
rana | Configuration | Computers | rossa notes |
**** Deleted
apps/emacs
apps/linux64/firefoxold
apps/linux64/comsol (old v. 3.5)
* running up2date on rossa
* rossa needs to be able move windows between monitors: Xinerama?
* there are permissions problems: controls on rossa can't
make and delete directories made by 'controls' elsewhere.
Some sort of user# or group issue? |
3523
|
Fri Sep 3 23:42:34 2010 |
Jenne | Update | PSL | PSL update of the day |
Rana and I were poking around on the PSL table today, getting a few more items raised to the correct height.
I checked the polarization state of the new NPRO by using a HWP to minimize the transmission through a PBS cube, and then compared the power transmitted through the cube vs. reflected. When the NPRO current was 0.772 \pm 0.001 (as read on the LCD), the transmission through the cube was 1.44mW, while the reflected was 10.53mW. The reading of the Ophir power meter with no incident light was 0.03mW. This factor of 10 means that the NPRO beam is ~10% circularly polarized and ~90% linearly polarized. In order to improve the beam, we need a Quarter Wave Plate, which it turns out we don't have. We need a QWP!
After that, using the linearly polarized part of my beam (maximizing the transmission through the PBS by rotating my HWP by 45deg), I tried to tune the angle of the polarizers that Rana pulled out of the MOPA. I think I'm confused / too tired, because I can only get the polarizer to reflect a bunch of light, and I can't get it to pass any significant amount of light through, no matter where in its actuation range I put it (It's on a rotation stage with a few degrees of range). It should just be a Brewster's Angle thing, and since I already have P-pol coming through the BS cube, this shouldn't be so hard.....
In any case, it may not be useful to do the final fine tuning of these polarizers until they are in their final places. The hacky stack of mounts that I have has some slop in the position / alignment of the base of the polarizer, so no matter what we'll have to redo the tuning after the mounts are finalized. |
3522
|
Fri Sep 3 13:04:30 2010 |
Koji | Frogs | Electronics | Cable cutting tools |
Yeah, this looks nice.
And I also like to have something I have attached. This is "HOZAN P-90", but we should investigate American ones
so that we can cut the wires classified by AWG.
Quote: |
I found this very interesting German maker of cool cable cutting tools. It's called Jokari.
We should keep it as a reference for the future if we want to buy something like that, ie RF coax cable cutting knives.
http://www.jokari.de/en.htm
|
|
Attachment 1: P90.jpg
|
|
3521
|
Fri Sep 3 11:23:16 2010 |
josephb | Configuration | Computers | rossa nvidia driver and dual monitor configuration |
At LLO the machines are running Centos 5.5. A quick login confirms this. Specifically the release is 2.6.18-194.3.1.el5.
Quote: |
Why are we running CentOS 4.8 instead of 5.5 ? What runs at LLO? What runs in Downs?
|
|
3520
|
Fri Sep 3 11:03:41 2010 |
Alberto | Frogs | Electronics | Cable cutting tools |
I found this very interesting German maker of cool cable cutting tools. It's called Jokari.
We should keep it as a reference for the future if we want to buy something like that, ie RF coax cable cutting knives.
http://www.jokari.de/en.htm |
3519
|
Fri Sep 3 06:55:42 2010 |
rana | Update | PSL | PSL beam hitting the PMC! |
NPRO
Koji and I inspected and photographed the laser after opening up its case. I then drilled the clearance holes in the 4 corners and tapped holes for 1/4-20. I was careful to tap with the laser sideways, to avoid shavings getting into the laser and suctioned out as much of the pieces as I could. The laser is now mounted on some bad 1/4-20 based NewFocus style pedestals. The riser block can now be made with 1/4-20 through holes and the laser will sit on its for corner feet. We'll make the base aluminum to avoid differential CTE based stress in the laser base.
We checked the level of the laser. With the new mounting the beam is level to within ~1 mrad and has a 4" beam height.
Faraday
I've mounted the Faraday Rotator from the old MOPA. It has 8-32 mounting holes (who's shafts are curiously not parallel). We need an aluminum block of the proper height (2 3/4" ??) to make a permanent solution.
I've also mounted the thin-film polarizer. This works well, but it also needs a block machined to get the mounting to be less Mickey Mouse.
Pockel Cell for phase correction and 35.5 MHz PMC modulation
The EOM is mounted as before on the angle bracket to align it for P-pol light. The beam now goes cleanly through there. No further mounting hardware required.
Lenses
The 2 lenses in the 'mode matching telescope' between the laser and the PMC are in place, but not placed with any accuracy.
By sheer luck, I saw the PMC flashing in the TEM27 mode without any alignment from me. Next step is to get the lens positions tuned and then do the beam scan on the beam going towards the PMC to verify the approximate mode matching. This is all crude, but I just want to get the beam going into the vacuum as fast as possible. |
3518
|
Thu Sep 2 23:35:33 2010 |
rana | Configuration | Computers | rossa nvidia driver and dual monitor configuration |
Why are we running CentOS 4.8 instead of 5.5 ? What runs at LLO? What runs in Downs? |
3517
|
Thu Sep 2 21:22:31 2010 |
Sanjit, Koji | Configuration | Computers | rossa nvidia driver and dual monitor configuration |
Simple steps (but don't try these on a working computer without getting some experience on a spare one, you may find it difficult to restore the system if something goes wrong):
- download the appropriate driver from NVIDIA website for this computer
- we did: NVIDIA GeForce 310 64bit Linux, version: 256.53, release date 2010.08.31
- keep/move the driver in /root (use "sudo" or "su")
- reboot the computer in "single user" mode
- in the GRUB screen edit the boot command by pressing the appropriate key listed in the screen
- in the boot command-line put " single" in the end (no other change is normally needed), don't save
- press ENTER and the system will reboot to a root shell (# prompt)
- cd /root
- run the NVIDIA driver script
- exit the shell (ctrl-d), let the system reboot
- it should flash (mostly green) "nvidia" screen before starting X
- in case of problems run system-config-display and revert to vesa driver
- login as "root" and run "nvidia-settings" from command line or GUI menu to add/configure display
|
3516
|
Thu Sep 2 17:43:30 2010 |
josephb | Update | CDS | One working BO output module, others not so much |
Joe and Kiwamu:
We found one bug in the RCG code, where the second input for the CDO32 part (32 binary output) was simply a repeat of the first input, and totally ignored the second input. This was fixed in the /advLigoRTS/src/epics/util/lib/CDO32.pm file by changing
$calcExp .= $::fromExp[0];
to
$calcExp .= $::fromExp[1];
This fix has been added to the svn. Unfortunately, while we have a single working binary output module, the 2nd and later modules do not seem to be responding at all. We've done the usual swaping parts of the path in both software and hardware and can't find any bad pieces in our model files or the actual hardware. That leaves me wondering about the c code, specifically if the CDO32Output[1], CDO32Output[2], and so forth array entries in the code are being handled properly. I'll try to get some thoughts on it from Alex tomorrow. |
3515
|
Thu Sep 2 16:45:48 2010 |
josephb | Update | CDS | Numbering scheme of the PCI bus |
Rolf has recently written a document describing how one should fill out an IO chassis and how the numbering works out. This can be found in the DCC at Rolf's PCIe numbering guide (T1000523).
Basically it works out that slot 1 corresponds to PCIe number 1, but slot 2 corresponds to PCIe number 6. And so forth. The following table gives a quick summary.
Slot |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
11 |
12 |
13 |
14 |
15 |
16 |
17 |
PCIe Number |
1 |
6 |
5 |
4 |
9 |
8 |
7 |
3 |
2 |
14 |
13 |
12 |
17 |
16 |
15 |
11 |
10 |
|
3514
|
Thu Sep 2 16:41:32 2010 |
steve | Configuration | SAFETY | laser is ON: safety glasses required! |
I hooked up interlock to the Innolight 2W 1064 nm in the enclosure. The manual shutter is closed on this unit.
SAFETY GLASSES REQUIRED ! |
3513
|
Thu Sep 2 14:11:17 2010 |
steve | Summary | PEM | south end crane balancing is completed |
The crane I -beam now leveled at all degrees of rotation. The lower hinge was moved southward about 1/4 of an inch. Performance was tested at 2000 lbs
Atm1, work in progress
Atm2, load test at 1 Ton
Atm3, service report |
Attachment 1: P1060798.JPG
|
|
Attachment 2: P1060800.JPG
|
|
Attachment 3: P1060804.JPG
|
|
3512
|
Thu Sep 2 01:48:23 2010 |
Jenne | Frogs | Treasure | Not cool.... |
This totally creeped me out when I found it wandering around on the floor not so far from my desk:

|
3511
|
Thu Sep 2 01:44:13 2010 |
Jenne | Update | PSL | PSL beam hitting the PMC! |
[Rana, Jenne]
More PSL progress.
The new laser was raised to a 4 inch beam height using basically the most randomly thrown together method possible. (It'll work just fine for aligning things, but we seriously need to get a nice block made.) The PMC and the nice Osamu-mirror mount to go into the PMC also have temporary risers, so we'll need to replace them with the real deal as soon as we get things back from the shop.
So far we've got (1) the lens after the laser, (2) a Half Wave Plate (no quarter wave plate yet), (3) steering mirror that will go after the EOM, (4) 2 steering mirrors to get into the PMC, in addition to all of the stuff that we did the other day. With all of this stuff we've got the beam hitting the 1st PMC mirror. We still don't have the EOM and AOM in the beam path however.
To get the rough alignment that we did, we turned on the new 2W NPRO, operating at the minimum power we could see on a card. We turned it off after use, so it is still off. Steve, we left the cable for the interlock sitting on the PSL table on the NW corner....can you please hook it up tomorrow? Also, after the interlock is installed we should go back to regular running laser hazard mode.
|
3510
|
Wed Sep 1 17:17:42 2010 |
rana | Update | Electronics | FSS Box Phase Noise from DAQ - Measurement setup modified |
With the setup now working, we should now test the power filtering for the crystal and amplifier. |
3509
|
Wed Sep 1 16:29:28 2010 |
Alberto | Update | Electronics | FSS Box Phase Noise from DAQ - Measurement setup modified |
Quote: |
The differences between this setup and the one used previously is the lack of the 50 Ohm terminator in the mixer output and
that the SR560 readout with the G=100 should come before the first SR560 via T, so as not to be spoiled by the high noise of the G=1 SR560.
|
I removed the 50 Ohm in-line terminator when I did the measurement with the SR785. The for some reason I was getting more noise, so I removed it.
Now I put it back in and I did the measurement with the DAQ. I also moved the SR560 that amplifies the signal for the DAQ, Tee'ing it with the input of the in-loop SR560.
Now the setup looks like this:

And the phase noise that I measure is this:

Comparing it with the phase noise measured with the previous setup (see entry 3506), you can see that the noise effectively is reduced by about a factor of 2 above 10 Hz.

|
3508
|
Wed Sep 1 12:34:14 2010 |
rana | Update | Electronics | FSS Box Phase Noise from DAQ |
The differences between this setup and the one used previously is the lack of the 50 Ohm terminator in the mixer output and
that the SR560 readout with the G=100 should come before the first SR560 via T, so as not to be spoiled by the high noise of the G=1 SR560. |
3507
|
Wed Sep 1 12:24:47 2010 |
josephb | Update | CDS | Trying to get up to date CDS code runnning |
Alex, Joe:
We copied the latest x02 to c1x02 and modified to our the config block in it.
We removed gds_node_id. We just have one number now, the dcuid, which is unique for each controller, simulated plant and IOP. Set site to C1 and host to c1sus.
Alex made the latest awgtpman backwards compatible, and checked that into svn.
We installed the latest framecpp onto c1sus from www.ldas-sc.ligo.caltech.edu/packages/ using wget.
wget www.ldas-sc.ligo.caltech.edu/packages/framecpp-1.18 and then used make.
This let us compile diagd on c1sus, using the command make stand in the /advLigoRTS/build area.
We copied gds from the seiteststand over at handford and are trying to build that on megatron. However, there's a bunch of packages we need for it to install properly. Alex said he'd work on that later, possibly trying to make some portable binaries.
Checked out the latest dataviewer into /opt/rtcds/caltech/c1/core/daq, however its not quite working yet either. This is another thing Alex said he'll work on later.
We are also going to test Alex and Rolf's kernel patch over on c1iscex on Centos base kernel (apparently they've been using Gentoo up at hanford for the test stands...) and see how that works. |
3506
|
Wed Sep 1 11:34:39 2010 |
Alberto | Update | Electronics | FSS Box Phase Noise from DAQ |
I measured the phase noise of the LO output of the FSS box from the DAQ. I'm attaching the results.
As we expected, the measurement is limited by the internal phase noise of the Marconi.

The measurement was done as shown in this diagram.

|
3505
|
Wed Sep 1 10:54:15 2010 |
steve | Update | PEM | more crane balancing |
Crane balancing at the south end is continuing today. |
3504
|
Wed Sep 1 08:40:28 2010 |
Alberto | Configuration | Electronics | PMC board unplugged, turned on Sorensen switches on 1Y1 rack |
Quote: |
Today I put the FSS frequency box back into the 1Y1 rack.
To power it on, I turned on the 24V and 15V Sorensen switches in the same rack.
The PMC crystal board in the same rack should not be affected (it runs with 10V), but, to make sure it was not powered, I disconnected it from its crate. Since the board was disconnected from the EOM for the PSL table's upgrade, I wanted to avoid having the RF output floating.
We just have to remember to plug it back in, when we need it again.
|
I just turned on the other Sorensen's too in 1Y1. |
3503
|
Wed Sep 1 08:36:59 2010 |
Koji | HowTo | PSL | 2W NPRO Mount designed with emachineshop.com software |
1. I can not see whether the attaching surface is flat or not.
It should have ~1mm step to avoid "the legs" of the laser at the four corners.
Otherwise we will have ~0.5mm space between the block and the laser
and will squish this gap by the screws => cause the deformation of the block and the laser.
2. The countersinks for the M4 screws can be much deeper so that we can use the existing M4 screws.
In any case, the long M4 screws are not rigid and also not common.
|
3502
|
Wed Sep 1 08:28:43 2010 |
Koji | Update | PSL | PSL upgrade update |
Quote: |
- We got the lenses from CVI for the mode matching, but not the metric screws for the laser mounting. I am tempted to tap holes in the laser base.
|
I am feeling that it is ok to carefully make new holes and threads as far as the holes do not penetrate the plate.
The thickness of the plate can be measured by the four holes at the corners.
|
3501
|
Wed Sep 1 07:52:27 2010 |
Alberto | Configuration | Electronics | PMC board unplugged, turned on Sorensen switches on 1Y1 rack |
Today I put the FSS frequency box back into the 1Y1 rack.
To power it on, I turned on the 24V and 15V Sorensen switches in the same rack.
The PMC crystal board in the same rack should not be affected (it runs with 10V), but, to make sure it was not powered, I disconnected it from its crate. Since the board was disconnected from the EOM for the PSL table's upgrade, I wanted to avoid having the RF output floating.
We just have to remember to plug it back in, when we need it again. |
3500
|
Tue Aug 31 19:46:00 2010 |
rana | Update | PSL | PSL upgrade update |
- Steve is handling the mount height increase for the PMC and RC steering mirrors, as well as a mount (non-steerable) for the ISS' AOM.
- Rana is working on the laser mount.
- Jenne is drawing and getting the PMC mount made.
- We got the lenses from CVI for the mode matching, but not the metric screws for the laser mounting. I am tempted to tap holes in the laser base.
|