I have measured the linearity of our triple resonant EOM (i.e. modulation depth versus applied voltage)

The attached figure is the measured modulation depth as a function of the applied voltage.

The linear behavior is shown below 4Vrms, this is good.

Then it is  slowly saturated as the applied voltage goes up above 4Vrms.

However for the resonance of 29.5MHz, it is difficult to measure below 7Vrms because of the small modulation depth.

 - - - - result from fitting - - -

11MHz: 91mrad/Vrms+2.0mrad

29.5MHz: 4.6mrad/Vrms+6.2mrad

55MHz:82mrad/Vrms+1.0mrad

Koji pointed out that logging into Nodus was being abnormally slow.  I tracked it down to the fact we had forgotten to update the address for the DNS server running on linux1 in the resolv.conf file on nodus.  Basically it was looking for a DNS server which didn't exit, and thus was timing out before going to the next one.  SSHing into nodus should be more responsive.

5) op340m has had its hosts table and other network files updated.  I also removed its outdated hosts.deny file which was causing some issues with ssh.

6) On op340m I started FSSSlowServo, with "nohup ./FSSSlowServo", after killing it on op540m.

I also kill RCthermalPID.pl, and started with "nohup ./RCthermalPID.pl" on op540m.

7) c1ass is fixed now.  There was a typo in the resolv.conf file (namerserver -> nameserver) which has been fixed.  It is now using the DNS server running on linux1 for all its host name needs.

8) I killed the autlockMCmain40m process running on op440m, modified the script to run on op340m, logged into op340m, went to /cvs/cds/caltech/scripts/MC and ran nohup ./autolockMCmain40m

9) Linux2 does not look like it has not been connected for awhile and its wasn't connected when we started the IP change over yesterday.  Is it supposed to still be in use?  If so, I can hook it up fairly easily.  op340m, as noted earlier, has been switched over.  Mafalda has been switched over.

10) c0rga has now been switched over. 

11) aldabella, the vacuum laptop has had its starting environment variables tweaked (in the /home/controls/.cshrc file) so that it looks on the 192.168.113 network instead of the 131.215.113.  This should mean Steve will not have any more trouble starting up his vacuum control screen.

12) Ottavia has been switched over.

13) At this time, only the GPIB devices and a few laptops remain to get switched over.

After Joe left:

1. Turned on op440m and returned him his keyboard and mouse.
2. Damped MC2.
3. Opened PSL shutter - locked PMC, FSS,
4. Started StripTool displays on op540m.
5. op340m doesn't respond to ping from anyone.
6. started FSS  SLOW and RCPID scripts on op540 - need to kill and restart on op430m.
7. ASS wouldn't come up - it doesn't know who linux1 is.
8. MC autolocker wouldn't run on op540m because of a perl module issue, started it on op440m - it needs to be killed and restarted on op430m.
9. probably mafalda, linux2, and op430m need some attention - they are all in the same rack.

As of 7:18 PM, the MC is locked and the PSL seems normal + all suspensions are damped and the ELOG is back up as well as the SVN.

 Designated vacuum control lap top is trouble some to use. Joe finally fixed it and I switched valve configuration back to vacuum normal. Shutter is open

A few machines have still not been changed over, including a few laptops, mafalda, ottavia, and c0rga.

All the front ends have been changed over.

fb40m died during a reboot and was replaced with a spare Sun blade 1000 that Larry had.  We had to swap in our old hard drive and memory.

All the front ends, belladonna, aldabella, and the control room machines have been switched over. Nodus was changed over after we realized we hosed the elog and svn by switching linux1's IP.

At this point, 90% of the machines seem to be working, although c0daqawg seems to be having some issues with its startup.cmd code.

The commercial resonant EOM of New Focus has the modulation efficiency of 50-150mrad/Vrms. ( This number is only true for those EOM made from KTP such as model4063 and model4463 )

Our triple-resonant EOM (made from KTP as well) has a 90mrad/Vrms and 80mrad/Vrms at the reosonances of 11MHz and 55MHz respectively.

Therefore our EOM is as good as those of company-made so that we can establish a new EOM company

Joe and Alex are working on the computers. Our vacuum system is temporary "All off" condition: meaning all valves are closed, so there is no pumping. cc1 = 1.6e-6 Torr

In the middle of the last month, Kiwamu and I went to Garilynn's lab to measure the phase maps of the new ITMs and SRMs.

Analysis of the phase map data were posted on the svn directory:
https://nodus.ligo.caltech.edu:30889/svn/trunk/docs/upgrade08/cocdocs/PhaseMaps/

The screen shots and the plots were summarized in a PDF file. You can find it here:
http://lhocds.ligo-wa.caltech.edu:8000/40m/Upgrade_09/Main_Optics_Phase_Maps

The RoCs for all of the PRMs are turned out to be ~155m. This is out of the spec (142m+/-5m) although the actual effect is not understand well yet..

These RoCs are almost independent from the radus of the assumed gaussian beam.
In deed, I have checked the dependence of the RoC on the beam spot position, and it turned out that the RoCs vary only little.
(In the SRMU01 case, for example, it varies from 153.5m to 154.9m.)
The beam radius of 3mm was assumed. The RoCs were calculated 20x20mm region around the center of the mirror with a 2mm mesh.
 

Hey, this looks nice, but can you provide us the comparison of rad/V with the resonant EOM of New Focus?

I have made a prototype circuit of the triple resonant EOM.

The attached is the measured optical response of the system.

The measured gains at the resonances are 8.6, 0.6 and 7.7 for 11MHz, 29.5MHz and 55MHz respectively.

I successfully got nice peaks at 11MHz and 55MHz. In addition resultant optical response is well matched with the predicted curve from the measured impedance.

However there is a difference from calculated response (see past entry) (i.e. more gains were expected)

Especially for the resonance of 29.5MHz, it was calculated to have gain of 10, however it's now 0.6. Therefore there must a big loss electrically around 29.5MHz.

I am going to re-analyze the impedance and model the performance in order to see what is going on.

IN VACUUM beam heights are ALL 5.5"  This is measured from the top of the optical table to the center of all TMs, mirrors and other optical components. This beam is ~36" above the floor.

PSL (inside of enclosure) main-output  beam: PMC, MZ, RC and ISS  are at 3" heights. IOO Angle & Position, MC-Trans and RFAM qpds are at 4"

ALL OTHER beam heights at atmosphere and  different ISCT (interferrometer sensing, control optical table)s are at 4"

The upgrade's input mode matching telescope design is complete.  A summary document is on the MMT wiki page, as are the final distances between the optics in the chain from the mode cleaner to the ITMs.  Unless we all failed kindergarden and can't use rulers, we should be able to get very good mode matching overlap.  We seem to be able (in Matlab simulation land) to achieve better than 99.9% overlap even if we are wrong on the optics' placement by ~5mm.  Everything is checked in to the svn, and is ready for output mode matching when we get there.

We were able to lock the Y-arm using Megatron and the RCG generated code, with nothing connected to c1iscey.

All relevant cables were disconnected from c1iscey and plugged into the approriate I/O ports, including the digital output.  Turns out the logic for the digital output is opposite what I expected and added XOR bitwise operators in the tst.mdl model just before it went out to DO board.  Once that was added, the Y arm locked within 10 seconds or so.  (Compared to the previous 30 minutes trying to figure out why it wouldn't lock).

I want to try to do the measurement with the network analyzer used as local oscillator, instead of the Marconis that I'm using now. Tha could give me better noise rejection. It would also give me information about the phase.

Also I wouldn't dislike abandoning the GPIB interfaces to acquire data.

I might have found the problem with the PLL that was preventing me from scanning the frequencies by 100KHz steps. A dumb flimsy soldering in the circuit was making the PLL unstable.

After I fixed that problem and also after writing a cleverer data acquisition script in Python,  I was able to scan continuosly the range 10-200MHz in about 20min (versus the almost 1.5-2 hrs that I could do previously). I'm attaching the results to this entry.

The 'smears' on the right side of the resonance at ~33MHz, are due to the PSL's sideband. I think I know how to fix that.

As you can see, the problem is that the model for the cavity transmission still does not match very well the data. As a result, the error on the cavity length is too big (~> 10 cm - I'd like to have 1mm).

Anyway, that was only my first attempt of scanning. I'm going to repeat the measurement today too and see if I can come out better. If not, than I have to rethink the model I've been using to fit.

I've added the control logic for the outputs going to the Contec Digital Output board.  This includes outputs from the QPD filters (2 filters per quadrant, 8 in total), as well as outputs going to the coil input sensor whitening.

At this point, the ETMY controls should have everything the end station FE normally does.  I'm hoping to do some testing tomorrow afternoon with this with a fully locked IFO.

 I was actually hoping that the alignment got better.

 oops, my bad.  I cranked the 33MHz modulation depth and forgot to put it back.  The slider should go back to around 3. 

I just aligned PRM and locked PRC and I noticed that SPOB is much higehr than it used to be. It's now about 1800, vs 1200 than it used to be last week.

Isn't anyone related to that? If so, may I please know how he/she did it?

Lately I've been trying to improve the PLL for the AbsL experiment so that it could handle larger frequency steps and thus speed up the cavity scan.

The maximum frequency step that the PLL could handle withouth losing lock is given by the DC gain of the PLL. This is the product of the mixer's gain factor K [rad/V ], of the laser's calibration C [Hz/V] and of the PLL filter DC gain F(0).

I measured these quantities: K=0.226 V/rad; C=8.3e6 Hz/V and F(0)=28.7dB=21.5. The max frequency step should be Delta_f_max = 6.4MHz.

Although in reality the PLL can't handle more than a 10 KHz step. There's probably some other effect that I'm not.

I'm attaching here plots of the PLL Open Loop Gain, of the PLL filter and of a spectra of the error point measured in different circumstances.

I don't have much time to explain here how I took all those measurements. After I fix the problem, I'm going to go go through those details in an elog entry.

Does anyone have any suggestion about what, in principle, might be limiting the frequency step?

I already made sure that both cables going to the mixer (the cable with the beat signal coming from the photodiode and the cable with the LO signal coming from the Marconi) had the same length. Although ideally, for phase locking, I would still need 90 degrees of phase shift between the mixing signals, over the entire frequency range for which I do the cavity scan. By now the 90 degrees are not guaranteed.

Also, I have a boost that adds another 20 dB at DC to the PLL's filter. Although it doesn't change anything. In fact, as said above calculating the frequency step, the PLL should be able to handle 100KHz steps, as I would want the PLL to do.

Did some more test to get better performance at higher frequencies.

Increased # taps to 4000 and reduced downsampling to 4, without changing the AA32 filters, from CORR, EMPH and the matching ADPT channels. But for testing I turned off AA32 from the input PEM channels. So that high frequency still gets blocked at CORR, but the adaptive filters have access to higher frequencies. Once we fix some reasonable downsampling, we should create corresponding AA filters.

I used only two channels, RANGER/GUR2_Y and GUR1_Z, and basically they had only one filter 0.1:0

This set up gave little better performance (more reduction at more frequencies), at some point even the 16HZ peak was reduced by a factor of 3. The 24Hz peak was a bit unstable, but became stable after I removed the Notch24 filters from PEM channels, to ensure that OAF is aware of those lines. There was some improvement also at the 24Hz peak.

[Jenne, Kiwamu]

The 2 SOS towers for the ITMs have been assembled, and are on the flow bench in the cleanroom.  Next up is to glue magnets, dumbells, guiderods and wire standoffs to the optics, then actually hang the mirrors.

I have installed a slow start throttle valve in front of V3  This spring loaded valve will cut down on the flow at high pressures. There will be no more sand storme

and static built-up during pump down.

There is lot of coherence between the error signal and PEM channels at 5-100Hz. We had been applying a 1Hz low pass filter to all the GUR and RANGER channels for stability. I turned those off and OAF still works with mu=0.0025, this will give us some more freedom. Kind of annoying for testing though, it takes about 45min to adapt!

In any case, there is no significant improvement at high frequencies as compared to our usual OAF performance. Also, the low frequency improvement (see previous e-log) is lost in this set up. I think, we have to adjust the number of taps and channels to do better at high frequencies. Also, delay can be important at these frequencies, needs some testing.

At 0.1-1.0Hz, there is some coherence between MC_L and RANGER_Y & GUR_Y, see the first figure. Also GUR_Z has low noise there. So I used all five of them, increased the gains of GUR_Z from 0.1 to 0.5. Some improvement near 0.5Hz. We possibly can not do any better with these PEM measurement, as the coherence of the adapted error signal and the PEM channels is almost zero, see the second figure. May be we need to think about placing the seismometers at different places/orientations.

However, there is lot more scope at higher frequencies, lot of coherence at 5-100Hz.

What is the change:

We will be moving the 131.215.113.XXX ip addresses of the martian network over to a 192.168.XXX.YYY scheme.

What will users notice:

Computer names (i.e. linux1, scipe25/c1dcuepics) will not change.  The domain name martian, will not change (i.e. linux1.martian.).  What will change is the underlying IP address associated with the host names.  Linux1 will no longer be 131.215.113.20 but something like 192.168.0.20.  If everything is done properly, that should be it.  There should be no impact or need to change anything in EPICS for example.  However, if there are custom scripts with hard coded IP addresses rather than hostnames, those would need to be updated, if they exist.

What needs to be done:

Each computer and router will need to either be accessed remotely, or directly, and the configuration files controlling the IP address (and/or dns lookup locations) be modified.  Then it needs to be rebooted so the configuration changes take effect. I'll be making an updated list of computers this week (tracked down via their physical ethernet cables), and next week, probably on Thursday, and then we simply go down the list one by one.

LINUX

For a linux machine, this means checking the /etc/hosts file and making sure it doesn't have old information.  It should look like:

127.0.0.1               localhost.localdomain localhost
::1             localhost6.localdomain6 localhost6

Then change the /etc/sysconfig/network-scripts/ifcfg-eth0 file (or ethX file depending on the ethernet card in question).  The IPADDR, NETWORK, and GATEWAY lines will need to be changed.  You can change the hostname (although I don't plan on it) by modifying the /etc/sysconfig/network file.

The /etc/resolv.conf file will need to be updated with the new DNS server location (i.e. 131.215.113.20 to 192.168.0.20 for example).

SOLARIS

Simlarly to linux, the /etc/hosts file will need to be updated and/or simplified.  The /etc/defaultrouter file will need to be updated to the new router ip.  /etc/defaultdomain will need to be updated.  The /etc/resolv.conf will need to be updated with the new dns server.

vxWorks

Looking at the vxWorks machines, the command bootChange can be used to view or edit the IP configuration.

The following is an example from c1iscey.

-> bootChange

'.' = clear field;  '-' = go to previous field;  ^D = quit

boot device          : eeE0
processor number     : 0
host name            : linux1
file name            : /cvs/cds/vw/pIII_7751/vxWorks
inet on ethernet (e) : 131.215.113.79:ffffff00
inet on backplane (b):
host inet (h)        : 131.215.113.20
gateway inet (g)     :
user (u)             : controls
ftp password (pw) (blank = use rsh):
flags (f)            : 0x0
target name (tn)     : c1iscey
startup script (s)   :
other (o)            :

value = 0 = 0x0

By updating the the host (name of machine where its mounting /cvs/cds from - i.e. linux1), inet on ethernet (the IP of c1iscey) and host inet (linux1's ip address), we should be able to change all the vxWorks machines.

LINUX1

The DNS server running on linux1 will need to be updated with the new IPs and domain information.  The host file on linux1 will also need to be updated for all the new IP addresses as well.

This will need to be handled carefully as the last time I tried getting away without the host file on linux1, it broke NFS mounting from other machines.  However, as long as the host on linux1 is kept in sync with the dns server files everything should work.

 I restarted the ELOG on NODUS just now. Our attempt to set up error logging worked - it turns out ELOG was choking on the .ps file attachment.

So for the near future: NO MORE .PS files! Use PDF - move into the 20th century at least.

matlab can directly make either PNG or PDF files for you, you can also use various other conversion tools on the web.

Of course, it would be nice if nodus could handle .ps, but its a Solaris machine and I don't feel like debugging this. Eventually, we'll give him away and make the new nodus a Linux box, but that day is not today.

The electrical shop has to connect the new power transformer at CES. This means we will have no AC power for ~8 hrs on Saturday, February 20

Is this date good for us to power down ALL equipment in the lab?

Rana:  Yes

 Again, this morning Zach told me that the elog had crashed while he was trying to post an entry.

I just restarted it.

This is a (sort of) known problem with the EPICS computers: it's generally called the 'sticky slider' problem, but of course it applies to buttons as well.  It happens after a reboot, when the MEDM control/readback values don't match the actual applied voltages.  The solution (so far) is just to `twiddle' the problematic sliders/button.  There's a script somewhere called slider_twiddle that does this, but I don't remember if it has PSL stuff in it.  A better solution is probably to have an individual slider twiddle script for each target machine, and add the running of that script to the reboot ritual in the wiki.

The low PMC transmission alarm was on this morning. The PMC alignment needs a touch up.

I checked the situation from my home and the problem was solved.

The main problem was undefined state of the autolocker and the strange undefined switch states, being associated with the bootfest and burtrestore.

- MC UP/DOWN status shows it was up and down. So I ran scripts/MC/mcup and scripts/MC/mcdown. These cleared the MC autolocker status.

- I had a problem handling the FSS. After mcup/mcdown above, I randomly pushed the "enable/disable" buttons and others, and with some reason, it recovered the handling. Actually it acquired the lock autonomously. Kiwamu may have also been working on it at the same time???

- Then, I checked the PSL loop. I disconnected the loop by pushing the "test" button. The DC slider changes the PZT voltage only 0~+24V. This is totally strange and I started pushing the buttons randomly. As soon as I pushed the  "BLANK"/"NORMAL" button, the PZT output got back under the control.

- Then I locked the PMC, MZ, and MC as usual.

Alberto: You must be careful as the modulations were restored.

[Jenne, Kiwamu]

It's been an iffy last few hours here at the 40m.  Kiwamu, Koji and I were all sitting at our desks, and the computers / RFM network decided to crash.  We brought all of the computers back, but now the RefCav and PMC don't want to lock.  I'm a wee bit confused by this.  Both Kiwamu and I have given it a shot, and we can each get the ref cav to sit and flash, but we can't catch it.  Also, when I bring the PMC slider rail to rail, we see no change in the PMC refl camera.  Since c1psl had been finicky coming back the first time, I tried soft rebooting, and then keying the crate again, but the symptoms remained the same.  Also, I tried burt restoring to several different times in the last few days, to see if that helped.  It didn't.  I did notice that MC2 was unhappy, which was a result of the burtrestores setting the MCL filters as if the cavity were locked, so I manually ran mcdown.  Also, the MC autolocker script had died, so Kiwamu brought it back to life.

Since we've spent an hour on trying to relock the PSL cavities (the descriptive word I'm going to suggest for us is persistent, not losers), we're giving up in favor of waiting for expert advice in the morning.  I suppose there's something obvious that we're missing, but we haven't found it yet......

 Zach made me notice that the elog had crashed earlier on this afternoon. 

I just restarted it with the restarting script.

Instructions on how to run the last one are now in the wiki page. Look on the "How To" section, under "How to restart the elog".

CES construction is progressing. The 40m suspensions are bearing well.

atm1, PEM  vs sus plots of 120 days

atm2, big pool walls are in place, ~10 ft east of south arm

atm3, 10 ft east of ITMY

atm4, ~60 ft east of ITMY

atm5, cold weather effect of N2 evaporator tower

Joe let me use the resonant EOM for GigE phase camera for a while.
Then, I immediately started to open it :)

it uses the MiniCIrcuits T5-1T transformer and a TOKO RCL variable inductor.

The photos are on the Picasa 40m album.

http://lhocds.ligo-wa.caltech.edu:8000/40m/40m_Pictures

Last night, I connected megatron's BO board to the analog dewhitening board.  However, I was unable to lock the y arm (although once I disconnected the cable and reconnected it back the xy220 the yarm did lock).

So either A) I've got the wrong cable, or B) I've got the wrong logic being sent to the analog dewhitening filters.

During testing, I ran into an odd continuous on/off cycle on one of the side filer modules (on megatron).  Turns out I had forgotten to use a ground input to the control filer bank (which allows you to both set switches as well as read them out), and it was reading a random variable.  Grounding it in the model fixed the problem (after re-making).

 I tried some combination of PEM channels and filters to improve OAF performance at other frequencies, where we do not have any improvement so far. There is progress, but still no success.

Here are the main things I tried:

For the ACC channels replaced the 0.1 Hz high pass filters by 3Hz high pass and turned off the 1: filter.

Then I tried to incorporate the Z ACC/GUR channels, with some reasonable combination of the others.

The Z axis Guralp and Accelerometers were making OAF unstable, so I put a 0.1 gain in all four of those.

Following the PEM  noise curves Rana has put up, we should probably use

• two ACC_Y channels (3:0, Notch24, AA32)
• two GUR_Z channels (filters: 0.1:0, 1:, AA32, gain 0,1)
• one RANGER_Y, just because it works (0.1:0, 1:, Notch24, AA32)

In the end I tried this combination, it was stable after I reduced the GUR_Z gain, but looked very similar to what we got before, no improvement at 5Hz or 0.5Hz. But there was a stable hint of better performance at > 40Hz.

Possibly we need to increase the GUR_Z gain (but not 1) and try to use ACC_Z channels also. Since we can not handle many channels, possibly using one GUR_Z and one ACC_Z would be worth checking.

The 2W NPRO from Valera arrived today and I haf hidden it somewere in the 40m lab!

Rana was so kind to make this entry for me

  I tried downsampling value 32 (instead of 16), to see if it has any effect on OAF. Last week I encountered some stability issue - adaptation started to work, but the mode cleaner was suddenly unlocked, it could be due to some other effect too.

One point to note is that different downsampling did not have any effect on the CPU meter (I tried clicking the "RESET" button few times, but no change).

Done. IFO available

I just started a measuremtn that will be running for the next hour or so. Please be careful with the interferometer.

I temporarily turned off the 166 modulation.

This morning the LSC scripts wheren't running properly. I had to reboot c1iscey, c1iscex, c1lsc, c1asc .

I burtrestored to Monday January 25 at 12:00. 

I turned the StripTool and ALARMS and BLRMS back on on op540m. Looks like it has been rebooted 5 days ago and no one turned these back on. Also, there was a bunch of junk strewn around its keyboard which I restrained myself from throwing in the trash.

The BLRMS trends should be active now.

We turned on the OAF again to make sure it works. We got it to work well with the Ranger as well as the Guralp channels. The previous problem with the ACC is that Sanjit and Matt were using the "X" channels which are aligned the "Y" arm. Another casualty of our ridiculous and nonsensical coordinate system. Long live the Right Hand Rule!!

The changes that were made are:

• use of RANGER channel (with ACC_MC1_X and/or ACC_MC2_X)
• mu = 0.01, tau = 1.0e-6, ntaps = 2000, nDown = 16
• nDelay = 5 and nDelay = 7 both work (may not be so sensitive on delay at low frequencies)
• Main changes: filter bank on the PEM channels - ASS_TOP_PEM_## filters: 0.1:0, 1:, Notch24, AA32, gain 1
• Added the AI800 filter for upsampling in MC1 (should not matter)

Other parameters which were kept at usual setting:

• CORR: AI32, gain = 1
• EMPH: 0.001:0, AA32, gain = 1
• ERR_MCL: no filters, gain = 1
• SUS_MC1: no filter, gain = 1
• PEM Matrix: All zero except: (24,1), (15,2), (18,3)
• ADAPT path filter: union of CORR and EMPH filters, gain 1
• XYCOM switches # 16-19 (last four on the right) OFF 

Screenshots are attached.

Burt snapshot is kept as: /cvs/cds/caltech/scripts/OAF/snaps/ass_burt_100126_211330.snap

taken using the script: /cvs/cds/caltech/scripts/OAF/saveOAF

we should put this in ASS screen.

ERROR Detected in filter ASS_TOP_PEM_24 (RANGER): 1: was actually typed as a 1Hz high pass filter!

(Correcting this one seems to spoil the adaptation)

Possibly this makes sense, we may not want to block witness signals in the 0.1-20 Hz range.

  11:40 PM: Leaving the lab with the OAF running on 5 PEM channels (Ranger + Guralp 1&2  Y & Z). There's a terminal open on op440m which will disable the OAF in ~2.8 hours. Feel free to disable sooner if you need the MC/IFO.

 You can turn the 166 off if you want. MZ is unhappy after its turned off, but that's just the thermal transient from removing the RF heat. After a several minutes, the heat goes away and the MZ can be relocked.

One of these days we should evaluate the beam distortion we get in EOMs because of the RF heat induced dn/dT. Beam steering, beam size, etc.