40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
 40m Log, Page 9 of 348 Not logged in
ID Date Author Type Category Subject
11005   Wed Feb 11 18:11:46 2015 KojiSummaryLSC3f modulation cancellation

33MHz sidebands can be elliminated by careful choice of the modulation depths and the relative phase between the modulation signals.
If this condition is realized, the REFL33 signals will have even more immunity to the arm cavity signals because the carrier signal will lose
its counterpart to produce the signal at 33MHz.

Formulation of double phase modulation

m1: modulation depth of the f1 modulation
m2: modulation depth of the f2 (=5xf1) modulation

The electric field of the beam after the EOM

$\dpi{120} E=E_0 \exp \left[ {\rm i} \Omega t + m_1 \cos \omega t +m_2 \cos 5 \omega t \right ]$
$\dpi{120} \flushleft = {\it E}_0 e^{{\rm i} \Omega t} \\ \times \left[ J_0(m_1) + J_1(m_1) e^{{\rm i} \omega t}- J_1(m_1) e^{-{\rm i} \omega t} + J_2(m_1) e^{{\rm i} 2\omega t}+ J_2(m_1) e^{-{\rm i} 2\omega t} + J_3(m_1) e^{{\rm i} 3\omega t}- J_3(m_1) e^{-{\rm i} 3\omega t} + \cdots \right] \\ \times \left[ J_0(m_2) + J_1(m_2) e^{{\rm i} 5 \omega t}- J_1(m_2) e^{-{\rm i} 5 \omega t} + \cdots \right]$
$\dpi{120} \flushleft = {\it E}_0 e^{{\rm i} \Omega t} \\ \times \left\{ \cdots + \left[ J_3(m_1) J_0(m_2) + J_2(m_1) J_1(m_2) \right] e^{{\rm i} 3 \omega t} - \left[ J_3(m_1) J_0(m_2) + J_2 (m_1) J_1(m_2) \right] e^{-{\rm i} 3 \omega t} + \cdots \right\}$

Therefore what we want to realize is the following "extinction" condition
$\dpi{120} J_3(m_1) J_0(m_2) + J_2(m_1) J_1(m_2) = 0$

We are in the small modulation regime. i.e. J0(m) = 1, J1(m) = m/2, J2(m) = m2/8, J3(m) = m3/48
Therefore we can simplify the above exitinction condition as

$\dpi{120} m_1 + 3 m_2 = 0$

m2 < 0 means the start phase of the m2 modulation needs to be 180deg off from the phase of the m1 modulation.

$\dpi{120} E = E_0 \exp\left\{ {\rm i} [\Omega t + m_1 \cos \omega t + \frac{m_1}{3} \cos (5 \omega t + \pi)] \right \}$

 Field amplitude m1=0.3, m2=-0.1 m1=0.2, m2=0.2 Carrier 0.975 0.980 1st order sidebands 0.148 9.9e-2 2nd 1.1e-3 4.9e-3 3rd 3.5e-7 6.6e-4 4th 7.4e-3 9.9e-3 5th 4.9e-2 9.9e-2 6th 7.4e-3 9.9e-3 7th 5.6e-4 4.9e-4 8th 1.4e-5 4.1e-5 9th 1.9e-4 5.0e-4 10th 1.2e-3 4.9e-3 11th 1.9e-4 5.0e-4 12th 1.4e-5 2.5e-5 13th 4.7e-7 1.7e-6 14th 3.1e-6 1.7e-5 15th 2.0e-5 1.6e-4

11019   Thu Feb 12 23:47:45 2015 KojiUpdateLSC3f modulation cancellation

- I built another beat setup on the PSL table at the South East side of the table.
- The main beam is not touched, no RF signal is touched, but recognize that I was present at the PSL table.
- The beat note is found. The 3rd order sideband was not seen so far.
- A PLL will be built tomorrow. The amplifier box Manasa made will be inspected tomorrow.

- One of the two beams from the picked-off beam from the main beam line was introduced to the beat setup.
(The other beam is used of for the beam pointing monitors)
There is another laser at that corner and the output from this beam is introduced into the beat setup.
The combined beam is introduced to PDA10CF (~150MHz BW).

- The matching of the beam there is poor. But without much effort I found the beat note.
The PSL laser had 31.33 deg Xtal temp. When the beat was found, the aux laser had the Xtal temp of 40.88.

- I could observe the sidebands easily, with a narrower BW of the RF analizer I could see the sidebands up to the 2nd order.
The 3rd order was not seen at all.

- The beat note had the amplitude of about -30dBm. One possibility is to amplify the signal. I wanted to use a spare channel
of the ALS/FOLL amplifier box. But it gave me rather attenuation than any amplification.
I'll look at the box tomorrow.

- Also the matching of two beams are not great. The PD also has clipping I guess. These will also be improved tomorrow

- Then the beat note will be locked at a certain frequency using PLL so that we can reduce the measurement BW more.

11028   Sat Feb 14 00:48:13 2015 KojiUpdateLSC3f modulation cancellation

[SUCCESS] The 3f sideband cancellation seemed worked nicely.

- Beat effeciency improved: ~30% contrast (no need for amplification)

- PLL locked

- 3f modulation sideband was seen

- The attenuation of the 55MHz modulation and the delay time between the modulation source was adjusted to
have maximum reduction of the 3f sidebands as much as allowed in the setup. This adjustment has been done
at the frequency generation box at 1X2 rack.

- The measurement and receipe for the sideband cancellation come later.

- This means that I jiggled the modulation setup at 1X2 rack. Now the modulation setup was reverted to the original,
but just be careful to any change of the sensing behavior.

- The RF analyzer was returned to the control room.

- The HEPA speed was reduced from 100% (during the action on the table) to 40%.

11029   Sat Feb 14 19:54:04 2015 KojiSummaryLSC3f modulation cancellation

Optical Setup

[Attachment 1]

Right before the PSL beam goes into the vacuum chamber, it goes through an AR-wedged plate.
This AR plate produces two beams. One of them is for the IO beam angle/position monitor.
And the other was usually dumped. I decided to use this beam.

A G&H mirror reflects the beam towards the edge of the table.
A 45deg HR mirror brings this beam to the beat set up at the south side of the table.
This beam is S-polarlized as it directly comes from the EOM.

[Attachment 2]

The beam from the PSL goes through a HWP and some matching lenses before the combining beam splitter (50% 45deg P).
The AUX laser beam is attenuated by a HWP and a PBS. The transmitted beam from the PBS is supposed
to have P-polarization. The beam alignment is usually done at the PSL beam side.

The combined beam is steered by a HR mirror and introduced to Thorlabs PDA10CF. As the PD has small diameter
of 0.5mm, the beam needed to be focused by a strong lens.

After careful adjustment of the beam mode matching, polarization, and alignment, the beatnote was ~1Vpp for 2.5Vdc.
In the end, I reduced the AUX laser power such that the beat amplitude went down to ~0.18Vpp (-11dBm at the PD,
-18dBm at the mixer, -27dBm at the spectrum analyzer) in order to minimize nonlinearity of the RF system and
in order that the spectrum analyzer didn't need input attenuation.

Electrical Setup

[Attachment 3]

The PD signal is mixed with a local oscillator signal at 95MHz, and then used to lock the PLL loop.
The PLL loop allows us to observe the peaks with more integration time, and thus with a better signal-to-noise ratio.

The signal from the PD output goes through a DC block, then 6dB attenuator. This attenuator is added to damp reflection
and distortion between the PD and the mixer. When the PLL is locked, the dominant signal is the one at 95MHz. Without this attenuator,
this strong 95MHz signal cause harmonic distortions like 190MHz. As a result, it causes series of spurious peaks at 190MHz +/- n* 11MHz.

10dB coupler is used to peep the PD signal without much disturbing the main line. Considering we have 6dB attanuator,
we can use this coupler output for the PLL and can use the main line for the RF monitor, next time.

The mixer takes the PD signal and the LO signal from Marconi. Marconi is set to have +7dBm output at 95MHz.
FOr the image rejection, SLP1.9 was used. The minicirsuit filters have high-Z at the stop band, we need a 50Ohm temrinator
between the mixer and the LPF.

The error signal from the LPF is fed to SR560 (G=+500, 1Hz 1st-order LPF). I still don't understand why I had to use a LPF
for the locking.
As the NPRO PZT is a frequency actuator, and the PLL is sensitive to the phase, we are supposed to use
a flat response for PLL locking. But it didn't work. Once we check the open loop TF of the system, it will become obvious (but I didn't).

The actuation signal is fed to the fast PZT input of the AUX NPRO laser.

Attachment 1: beat_setup1.JPG
Attachment 2: beat_setup2.JPG
Attachment 3: electrical_setup.pdf
11031   Sat Feb 14 20:37:51 2015 KojiSummaryLSC3f modulation cancellation

Experimental results

- PD response [Attachment 1]

The AUX laser temperature was swept along with the note by Annalisa [http://nodus.ligo.caltech.edu:8080/40m/8369]
It is easier to observe the beat note by closing the PSL shutter as the MC locking yields more fluctuation of the PSL
laser freuqency at low frequency. Once I got the beat note and maximized it, I immediately noticed that the PD response
is not flat. For the next trial, we should use Newfocus 1611. For the measurement today, I decided to characterize the
response by sweeping the beat frequency and use the MAXHOLD function of the spectrum analyzer.

The measured and modelled response of the PD are shown in the attachment 1. It has non-intuitive shape.
Therefore the response is first modelled by two complex pole pair at 127.5MHz with Q of 1, and then the residual was
empirically fitted with 29th polynomial of f.

- Modulation profile of the nominal setting [Attachment 2]

Now the spectrum of the PD output was measured. This is a stiched data of the spectrum between 1~101MHz and 99~199MHz
that was almost simultaneously measured (i.e. Display 1 and Display 2). The IF bandwidth was 1kHz. The PD response correction
described above was applied.

It obviously had the peaks associated with our main modulations. In addition, there are more peaks seen.
The attachment 2 breaks down what is causing the peaks.

• Carrier: The PLL LO frequency is 95MHz. Therefore the carrier is locked at 95MHz.
• Modulation sidebands (11/55MHz series):
Series of sidebands are seen at the both side of the carrier. Their frequency is 95MHz +/- n * fmod  (fmod = 11.066128MHz).
Note that the sidebands for n>10 were above 200MHz, and n<-9 (indicated in gray) were folded at 0Hz.
With this measurement BW, the following sidebands were buried in the noise floor.
n = -8, -12, -13, and -14, n<= -16, and n>=+7
• Modulation sidebands for IMC and PMC (29.5MHz and 35.5MHz):
First order sidebands for the IMC and PMC modulations of sidebands are seen at the both side of the carrier.
Their frequency is 95MHz +/- 29.5MHz or 33.5MHz. The PMC modulation sidebands are supposed to be blocked
by the PMC. However, due to finite finesse of the PMC, small fraction of the PMC sidebands are transmitted.
In deed, it is comparable to the modulation depth of the IMC one.
• RF AM or RF EMI for the main modulation and the IMC modulationand:
If there is residual RF AM in the PSL beam associated with the IMC and main modulations, it appears as the
peaks at the modulation frequency and its harmonics. Also EM radiation couples into this measument RF system
also appears at these frequencies. They are seen at n * fmod  (n=1,2,4,5) and 29.5MHz.
• Reflection/distortion or leakage from mixer IF to RF:
The IF port of the mixer naturally has 190MHz signal when the PLL is locked. If the isolation from the IF port to the RF port
is not enough, this signal can appear in the RF monitor signal via an imperfection of the coupler or a reflection from the PD.
Also, if the reflecrtion/distortion exist between the PD and the mixer RF input, it also cause the signal around 190MHz.
It is seen at 190MHz +/- n* fmod. In the plot, the peak at n=0, -1 are visible. In fact these peak were secondarily dominant
in the spectrum when there was no 6dB attenuation in the PD line. WIth the attenuator, they are well damped and don't disturb
the main measurment.

From the measured peak height, we are able to estimate the modulation depths for 11MHz, 55MHz, IMC modulations, as well as
the relative phase of the 11MHz and 55MHz modulation. (It is not yet done).

- 3f modulation reduction [Attachment 3]

Now, the redcution of the 3f modulation was tried. The measured modulation levels for the 11MHz and 55MHz were almost the same.
The calculation predicts that the modulation for the 55MHz needs to be 1/3 of the 11MHz one. Therefore the attenuation of 9dB and 10dB
of the modulation attenuation knob at the frequency generation box were tried.

To give the variable delay time in the 55MHz line, EG&G ORTEC delay line unit was used. This allows us to change the delay time from
0ns to 63.5ns with the resolution of 0.5ns. The frequency of 55MHz yields a phase sensitivity of ~20deg/ns (360deg/18ns).
Therefore we can adjust the phase with the precision of 10deg over 1275deg.

The 3rd-order peak at 61.8MHz was observed with measurement span of 1kHz with very narrow BW like 30Hz(? not so sure). The delay
time was swept while measuring the peak height each time. For both the atteuation, the peak height clearly showed the repeatitive dependence
with the period of 18ns, and the 10dB case gave the better result. The difference between the best (1.24e-7 Vpk) and the worst (2.63e-6 Vpk)
was more than a factor of 20.
The 3rd-order peak in the above broadband spectrum measurement was 6.38e-6 Vpk. Considering the attenuation
of the 55MHz modulation by 10dB, we were at the exact unluck phase difference.
The improvement expected from the 3f reduction (in the 33MHz signal)
will be about 50, assuming there is no other coupling mechanism from CARM to REFL33.

I decided to declare the best setting is "10dB attenuation & 28ns delay".

- Resulting modulation profile [Attachment 4]

As a confirmation, the modulation profie was measured as done before the adjustment.
It is clear that the 3rd-order modulation was buried in the floor noise. 10dB attenuation of the 55MHz modulation yields corresponding reduction of the sidebands.
This will impact the signal quality for the 55MHz series error signals, particularly 165MHz ones. We should consider to install the Teledyne Cougar amplifier
next to the EOM so that we can increase the over all modulation depth.

Attachment 1: beat_pd_response.pdf
Attachment 2: beat_nominal.pdf
Attachment 3: 3f_reduction.pdf
Attachment 4: beat_3f_reduced.pdf
6929   Fri Jul 6 09:27:40 2012 steveUpdateVAC4 days at atm

I'm looking for some movement indicators of the vent-pump down events.

Attachment 1: vent_moves.png
9576   Mon Jan 27 09:08:00 2014 SteveUpdateVAC4 days at atmosphere

Attachment 1: day4atm.png
Attachment 2: vent76bgTp3d4.png
8473   Mon Apr 22 19:48:56 2013 JenneUpdate40m Upgrading4 pins enough?

Are 4 of these spring loaded pins enough?  I'm not sure how one pin can hold 2 lids at each point.  It seems like we need 8 pins.

8475   Tue Apr 23 15:00:20 2013 JenneUpdate40m Upgrading4 pins enough?

 Quote: Are 4 of these spring loaded pins enough?  I'm not sure how one pin can hold 2 lids at each point.  It seems like we need 8 pins.

Steve has explained to me that the pins will go in between the 2 lids, with a big washer, so that one pin holds both lids at the same time.  4 is the right number.

11158   Mon Mar 23 09:42:29 2015 SteveSummaryIOO4" PSL beam path posts

To achive the same beam height each components needs their specific post height.

 Beam Height Base Plate Mirror Mount Lens Mount Waveplates-Rotary 0.75" OD. SS Post Height 4" Thorlabs BA2 Newport LH-1 2.620" 4" Thorlabs BA2 Polaris K1 2.620" 4" Thorlabs BA2 Polaris K2 2.220" 4" Thorlabs BA2 Thorlabs LMR1 2.750" 4" Thorlabs BA2 New Focus 9401 2.120" 4" Thorlabs BA2 Newport U100 2.620" 4" Thorlabs BA2 Newport U200 2.120" 4" Newport 9021 LH-1 2.0" PMC-MM lens with xy translation stage: Newport 9022, 9065A    Atm3 4" Newport 9021 LH-1 1.89 MC-MM lens with translation stage: Newport 9022, 9025        Atm2

We have 2.625" tall, 3/4" OD SS posts for Polaris K1 mirror mounts: 20 pieces

Ordered Newport LH-1 lens mounts with axis height 1.0

Attachment 1: .75odSSpost.pdf
Attachment 2: MC_mml_trans_clamp.jpg
Attachment 3: PMCmmLn.jpg
12995   Wed May 17 08:19:59 2017 SteveUpdateSUS4.1M earthquake

Sus dampings recovered. ETMY oplev needs to be recentered.

### GV May 17 11am: I shut down the BS, SRM, ITMX and ITMY watchdogs, as the coil-driver boards for these optics are presently not installed.

Attachment 1: eq_4.1_SantaBarbara.png
Attachment 2: 4.1m_Isla_Vista_CA.png
11903   Mon Dec 28 14:12:23 2015 SteveUpdateSUS4.2M EQ

Suspensions are recovered after 4.2 Mag earth quake. No obvoius sign of damage.

Attachment 1: 4.2Meq.png
Attachment 2: recovered4.2M.png
9556   Wed Jan 15 13:05:30 2014 JenneUpdatePEM4.4 EQ in Fontana, CA

It looks like there was a 4.4 magnitude earthquake near Fontana, CA around 1:30am today.  This tripped all of the suspension watchdogs, which Q has just now re-enabled.

9559   Thu Jan 16 08:19:29 2014 SteveUpdatePEM4.4 and 3.8M local earth quakes

 It looks like there was a 4.4 magnitude earthquake near Fontana, CA around 1:30am today.  This tripped all of the suspension watchdogs, which Q has just now re-enabled.

Earth quake shake down yesterday Atm1

Atm2, today's shake

Attachment 1: local4.4eq.png
Attachment 2: local3.8eq.png
11904   Wed Dec 30 11:09:52 2015 SteveUpdateSUS4.4M EQ

Suspensions recovered after 4.4 Mag EQ

Attachment 1: 4.4MeqDevore.png
Attachment 2: free.png
9729   Mon Mar 17 09:27:05 2014 SteveUpdateSUS4.4M local earthquake

It looks like that ETMX have  2 sticky magnets.

Attachment 1: 4.4M-Encino.png
Attachment 2: 3.9-4.4Meq.png
Attachment 3: EQdamage4.4.png
9734   Mon Mar 17 20:44:42 2014 ranaUpdateSUS4.4M local earthquake
9735   Mon Mar 17 21:55:36 2014 KojiUpdateSUS4.4M local earthquake

It was little bit surprising to me but Rana's professorial rock'n roll excitation released its sticking on the unconfirmed thing by unconfirmed reason.

I aligned the Xarm manually and via ASS.

Now we are back in the normal state.

9736   Tue Mar 18 00:51:02 2014 JenneUpdateSUS4.4M local earthquake

I am really, really happy to hear that it was just a sticking situation.  Really happy.

9737   Tue Mar 18 08:31:37 2014 SteveUpdateSUS4.4M local earthquake & its miracle

 Quote: It was little bit surprising to me but Rana's professorial rock'n roll excitation released its sticking on the unconfirmed thing by unconfirmed reason. I aligned the Xarm manually and via ASS. Now we are back in the normal state.

This recovery proceeder deserves a pattern

Note: IR shield glass position variations,  Atm4

Attachment 1: miracel.png
Attachment 2: ETMX_LR.JPG
Attachment 3: ETMX_LR-UL.JPG
Attachment 4: ETMX_UL-LL-S-IRshield.jpg
11914   Wed Jan 6 08:09:04 2016 SteveUpdatePEM4.5 Mag Banning EQ

IFO restored after 4.5 Mag Banning, Ca earthquake.

Attachment 1: 4.5Mag__Banning.png
13829   Thu May 10 08:45:16 2018 SteveUpdateGeneral4.5M eq. Cabazon, CA

20180508 4:49am Cabazon earth quake 4.5M at 79 miles away.  ETMX is in load cell measurment condition.

 Quote: There was an earthquake, all watchdogs were tripped, ITMX was stuck, and c1psl was dead so MCautolocker was stuck. Watchdogs were reset (except ETMX which remains shutdown until we finish with the stack weight measurement), ITMX was unstuck using the usual jiggling technique, and the c1psl crate was keyed.

Attachment 1: Cabazon4.5m79m.png
Attachment 2: 4.5Meq.png
1420   Tue Mar 24 09:04:02 2009 steveUpdateSUS4.8 mag earthquake

SRM, ITMX, ETMX, ITMY and ETMY lost damping at 4:55am this morning from 4.8 magnitude earthquake.

Their damping were restored.

C1:SUS-ITMX_URSEN_OUTPUT swich was found in off position. It was turned on.

MZehnder  and MC were locked.

The WFS qpd spot needs recentering

268   Fri Jan 25 15:53:59 2008 AlbertoUpdateElectronics40 dB from the 3rd order Chebyschev
I managed to tune the 7 knobs in the 3rd order Chebyshev bandpass filter obtaining the tranfer function attached to this entry. We have now 40 dB of attenuation between 166 Mhz and 133 and 199. With this tuning the insertion loss is rather high. We need a better one.

Alberto
Attachment 1: 166MhzElog.png
2283   Tue Nov 17 15:54:34 2009 ranaSummaryPEM40 days of weather

the inside temperature is alarming at the red level today - should check if the HIHI value is set correctly

Attachment 1: Untitled.pdf
1717   Tue Jul 7 15:08:49 2009 KojiSummaryPhotos40 high school students visited 40M

Alan and Alberto conducted a tour of 40 high-school students.
It may be the same tour that Rana found a spare PMC during the tour explanation as far as I remember...

Attachment 1: IMG_1848.jpg
16261   Tue Jul 27 23:04:37 2021 AnchalUpdateLSC40 meter party

[ian, anchal, paco]

After our second attempt of locking PRFPMI tonight, we tried to resotre XARM and YARM locks to IR by clicking on IFO_CONFIGURE>Restore XARM (POX) and IFO_CONFIGURE>Restore YARM (POY) but the arms did not lock. The green lasers were locked to the arms at maximum power, so the relative alignments of each cavity was ok. We were also able to lock PRMI using IFO_CONFIGURE>Restore PRMI carrier.

This was very weird to us. We were pretty sure that the aligment is correct, so we decided to cehck the POX POY signal chain. There was essentially no signal coming at POX11 and there was a -100 offset on it. We could see some PDH signal on POY11 but not enough to catch the locks.

We tried running IFO_CONFIGURE>LSC OFFSETS to cancel out any dark current DC offsets. The changes made by the script are shown in attachment 1.

We went to check the tables and found no light visible on beam finder cards on POX11 or POY11. We found that ITMX was stuck on one of the coils. We unstuck it using the shaking method. The OPLEVs on ITMX after this could not be switched on as the OPLEV servo were railing to limits. But when we ran Restore XARM (POX) again, they started working fine. Something is done by this script that we are not aware of.

We're stopping here. We still can not lock any of the single arms.

Wed Jul 28 11:19:00 2021 Update:

[gautam, paco]

Gautam found that the restoring of POX/POY failed to restore the whitening filter gains in POX11 / POY11. These are meant to be restored to 30 dB and 18 dB for POX11 and POY11 respectively but were set to 0 dB in detriment of any POX/POY triggering/locking. The reason these are lowered is to avoid saturating the speakers during lock acquisition. Yesterday, burt-restore didn't work because we restored the c1lscepics.snap but said gains are actually in c1lscaux.snap. After manually restoring the POX11 and POY11 whitening filter gains, gautam ran the LSCOffsets script. The XARM and YARM were able to quickly lock after we restored these settings.

The root of our issue may be that we didn't run the CARM & DARM watch script (which can be accessed from the ALS/Watch Scripts in medm). Gautam added a line on the Transition_IR_ALS.py script to run the watch script instead.

Attachment 1: Screenshot_2021-07-27_22-19-58.png
7445   Thu Sep 27 13:05:55 2012 Eric GustafsonUpdateLSC40 meter photodiode frequency response measurement system installation

Jenne, Mike and I installed all of the post holders we could today including: REFL11, REFL33, REFL55, AS55, MCRef, POX11 and POP55.  We did not install AS110, POY or REFL165 because there are interferences that will require moving stuff around. We also did not mount POP22 because it is a peely wally ThorLabs PD that will be replaced by a strong, straight and right thinking LIGO PD in the fullness of time.  We did move it out of the way however which is no more than it deserves. Next step this afternoon Mike and I will install all of the telescopes and launching hardware.  Then with the help of Steve we will begin routing the fibers.  The splitter module will be here by next Monday, the laser by the following Friday and then we will light up the fibers.

7448   Thu Sep 27 17:00:41 2012 Eric GustafsonUpdateLSC40 meter photodiode frequency response measurement system installation

Mike and I installed all of the telescopes and launching hardware for REFL11, REFL33, REFL55, AS55, MCRef, POX11 and POP55. On Monday afternoon Steve will work with us on the fiber routing.  Steve is buying some protective covers for the fibers.

3081   Wed Jun 16 18:12:16 2010 nancyConfigurationComputers40MARS

i added my laptop's mac address to teh martian at port 13 today.

3083   Wed Jun 16 18:44:07 2010 AlbertoConfigurationComputers40MARS

 Quote: i added my laptop's mac address to teh martian at port 13 today.

No personal laptop is allowed to the martian network. Only access to the General Computing Side is permitted.

8782   Fri Jun 28 11:33:32 2013 SteveUpdate 40MARS wireless network problem

 Quote: I'm not sure what's going on today but we're seeing ~80% packet loss on the 40MARS wireless network.  This is obviously causing big problems for all of our wirelessly connected machines.  The wired network seems to be fine. I've tried power cycling the wireless router but it didn't seem to help.  Not sure what's going on, or how it got this way.  Investigating...

Mike and Christian brought over a Mac laptop for surf Alex.

They power cycled the wireless router of 40Marsh and labtops are working.  Seeing 75-80% signals on all 3 Dell lab top sisters at both end of the lab

8605   Tue May 21 16:23:06 2013 ManasaUpdateGeneral40MARS wireless network problem RETURNS

 Quote: Here's an example of the total horribleness of what's happening right now: controls@rossa:~ 0$ping 192.168.113.222 PING 192.168.113.222 (192.168.113.222) 56(84) bytes of data. From 192.168.113.215 icmp_seq=2 Destination Host Unreachable From 192.168.113.215 icmp_seq=3 Destination Host Unreachable From 192.168.113.215 icmp_seq=4 Destination Host Unreachable From 192.168.113.215 icmp_seq=5 Destination Host Unreachable From 192.168.113.215 icmp_seq=6 Destination Host Unreachable From 192.168.113.215 icmp_seq=7 Destination Host Unreachable From 192.168.113.215 icmp_seq=9 Destination Host Unreachable From 192.168.113.215 icmp_seq=10 Destination Host Unreachable From 192.168.113.215 icmp_seq=11 Destination Host Unreachable 64 bytes from 192.168.113.222: icmp_seq=12 ttl=64 time=10341 ms 64 bytes from 192.168.113.222: icmp_seq=13 ttl=64 time=10335 ms ^C --- 192.168.113.222 ping statistics --- 35 packets transmitted, 2 received, +9 errors, 94% packet loss, time 34021ms rtt min/avg/max/mdev = 10335.309/10338.322/10341.336/4.406 ms, pipe 11 controls@rossa:~ 0$  Note that 10 SECOND round trip time and 94% packet loss.  That's just beyond stupid.  I have no idea what's going on.

## This has not been fixed!

Temporary solution: I ssh'd to nodus from the 40m wifi network and was able to connect to the FE machines.This works but the bandwidth is limited this way as expected.

40m MARS network needs to be fixed.

8540   Tue May 7 17:43:51 2013 JamieUpdateComputers40MARS wireless network problems

I'm not sure what's going on today but we're seeing ~80% packet loss on the 40MARS wireless network.  This is obviously causing big problems for all of our wirelessly connected machines.  The wired network seems to be fine.

I've tried power cycling the wireless router but it didn't seem to help.  Not sure what's going on, or how it got this way.  Investigating...

8541   Tue May 7 18:16:37 2013 JamieUpdateComputers40MARS wireless network problems

Here's an example of the total horribleness of what's happening right now:

controls@rossa:~ 0$ping 192.168.113.222 PING 192.168.113.222 (192.168.113.222) 56(84) bytes of data. From 192.168.113.215 icmp_seq=2 Destination Host Unreachable From 192.168.113.215 icmp_seq=3 Destination Host Unreachable From 192.168.113.215 icmp_seq=4 Destination Host Unreachable From 192.168.113.215 icmp_seq=5 Destination Host Unreachable From 192.168.113.215 icmp_seq=6 Destination Host Unreachable From 192.168.113.215 icmp_seq=7 Destination Host Unreachable From 192.168.113.215 icmp_seq=9 Destination Host Unreachable From 192.168.113.215 icmp_seq=10 Destination Host Unreachable From 192.168.113.215 icmp_seq=11 Destination Host Unreachable 64 bytes from 192.168.113.222: icmp_seq=12 ttl=64 time=10341 ms 64 bytes from 192.168.113.222: icmp_seq=13 ttl=64 time=10335 ms ^C --- 192.168.113.222 ping statistics --- 35 packets transmitted, 2 received, +9 errors, 94% packet loss, time 34021ms rtt min/avg/max/mdev = 10335.309/10338.322/10341.336/4.406 ms, pipe 11 controls@rossa:~ 0$


Note that 10 SECOND round trip time and 94% packet loss.  That's just beyond stupid.  I have no idea what's going on.

8762   Thu Jun 27 05:44:51 2013 ranaUpdate 40MARS wireless network problems

 Quote: I'm not sure what's going on today but we're seeing ~80% packet loss on the 40MARS wireless network.  This is obviously causing big problems for all of our wirelessly connected machines.  The wired network seems to be fine. I've tried power cycling the wireless router but it didn't seem to help.  Not sure what's going on, or how it got this way.  Investigating...

I'm still seeing some problems with this - some laptops are losing and not recovering any connection. What's to be done next? New router?

8763   Thu Jun 27 10:45:41 2013 SteveUpdateGeneral40MARS wireless network problems

Quote:

 Quote: I'm not sure what's going on today but we're seeing ~80% packet loss on the 40MARS wireless network.  This is obviously causing big problems for all of our wirelessly connected machines.  The wired network seems to be fine. I've tried power cycling the wireless router but it didn't seem to help.  Not sure what's going on, or how it got this way.  Investigating...

I'm still seeing some problems with this - some laptops are losing and not recovering any connection. What's to be done next? New router?

We had the same problem yesterday. However the Vacuum Dedicated laptop worked with fewer disconnects. Christian is coming over this after noon to look at this issue.

This happened a few weeks ago and it recovered misteriously. Jamie did not understand it.

15456   Mon Jul 6 15:10:40 2020 JonSummaryBHD40m --> A+ BHD design analysis

As suggested last week, Hang and I have reviewed the A+ BHD status (DRD, CDD, and reviewers' comments) and compiled a list of key unanswered questions which could be addressed through Finesse analysis.

In anticipation of others helping with this modeling effort, we've tried to break questions into self-contained projects and estimated their level of difficulty. As you'll see, they range from beginner to Finesse guru.

6720   Wed May 30 22:04:13 2012 JenneBureaucracyGeneral40m Action Items

.....including:

fix Q of Vio2 filter in SUS. - JENNE

Switch power source for beatnote PD's amplifiers from temporary power supplies under PSL table to permanent taking the power from a rack.

6843   Thu Jun 21 02:57:16 2012 JenneBureaucracyGeneral40m Action Items

PRIORITY ITEMS:

ASS doesn't run on Ubuntu!
Put beatbox back, simultaneous arm ALS
Input matricies, output filters to tune SUS.  check after upgrade.
POX11 whitening is not toggling the analog whitening???
Look into PMC PZT drift - PZT failing? Real MC length change?
Vent planning / organization

THE FULL LIST:

General

Audio system for the signals!!!! Even a crappy one!

SUS

Input matricies, output filters to tune SUS.  Check after upgrade.

IFO

Fix occasional common-mode power transient in the arm transmissions. Probably an alignment thing. Would ISS help?

Drift of the green incident axis -> Assess the amount of the drift / replace the mount

Calibration of POP22 / AS110

PMC/IMC/ARM characterization (loss, finesse, reflectivity, etc)

Arm cavity sweeps, mode scan

Align AS OSA (others?)

Investigate PRMI glitches, instability

PZT or Picomotor mounts for PSL/ALS beams

ALS on the both arm simultaneously / common / diff ALS scripts

Measure green locking (Aux laser to arm) transfer functions, residual spectra

Measure oplev spectra while locking Xgreen - see if the optics are particularly noisy

Measure Xarm residual motion using POX while ALS is engaged.

Fix Vio2 filter modules on SUS

Switch power supply for amplifiers of beatnote signal to rack power

Add temp sensors for end lasers to CDS slow channels

Put windows / pickoffs on PSL table for (a) green trans camera, (b) GTRY, (c) GTRX

CDS

Capture OSA signals in CDS (the 'scope TDS1001B has a USB port in the back for connecting to the computer)

Transmon (arms) for high and low power

POX11 whitening is not toggling the analog whitening???

Install guardians to monitor EPICS values

Electronics

Actuator noise level characterization (coil driver response in V/m & coil driver noise level V/rtHz)

Improvement of POP22/110/AS110 RF circuits?

MEDM

Complete 40m overview screen - everything should be clickable with pseudo 3D icons

Script to generate a MEDM tree

Resurrect MEDM snapshots

New ! buttons on every screen, include wiki page

SCRIPT

Daily diagnosis of the MC spot positions (there must be something already...)

Daily/occasional adjustment of the incident axis on the MC

Panic button on Watchdog screen isn't working on Ubuntu

OPLEV/OSEM trending script before the IFO work for diagnosis. Put into 40m summary screen.

Auto-locker for arms

Auto-locker for PSL things

Diagnostic script for CDS - mx_stream, other stuff.

Make sure scripts are all svn-ed

Video

If each video screen has a caption, that would be great

GUI interface of "videoswitch"

Ubuntu vs. CentOS

Upgrade Ottavia to Ubuntu, make sure connect to DTT, Dataviewer, AWG.

MM

IPPOS beam measurement

AS beam measurement (if beam is bright enough)

Mode matching calculations, sensitivity to MC waist measurement errors, PRM position

Think up diagnostic measurement to determine mode matching to PRC while chambers are open, while we tweak MMT

Use sensoray to capture, measure beam mode at AS, POP

Stray Light

Scattered light measurement at the end stations: design / confirmation of the mechanical parts/optics/cameras

Align AUX laser into dark port

Assemble in-vac beam dumps - how many do we need?

OAF

OAF comparison plot, both online and offline, comparing static, adaptive and static+adaptive

Static-only OAF noise budget (Adaptive noise budget as next step)

Script for daily / weekly re-calculation of Wiener, post to elog if need changing

Tip Tilts

Prepare electronics for TTs (coil drivers)

In-air TT testing to confirm we can control / move TTs before we vent

Connect TTs to digital system and controls, lay cables if needed

Determine whether we need to add a new flange to OMC chamber

RF Photodiodes

Opto Energy diode laser - purchase

Set everything up

Demod board for AS110 - so we can also have POP110?

13560   Fri Jan 19 15:22:19 2018 Udit KhandelwalSummaryGeneral40m CAD update 2018/01/19

1. All parts will be now named according to the numbering system in this excel sheet: LIGO 40m Parts List in dropbox folder [40mShare] > [40m_cad_models] > [40m Lab CAD]
2. I've placed optical tables in the chambers at 34.82" from the bottom for now. This was chosen by aligning the centre of test mass of SOS assembly (D960001) with that of vacuum tube (Steve however pointed out last week they might not necessarily be concentric).

2824   Wed Apr 21 11:32:31 2010 josephbUpdateCDS40m CDS hardware update and software requests

This is mostly a reminder to myself about what I discussed with Jay and Alex this morning.

The big black IO chassis are "almost" done.  Except for the missing parts.  We have 2 Dolphin, 1 Large and 1 Small I/O Chassis due to us.  One Dolphin is effectively done and is sitting in the test stand.  However, 2 are missing timing boards, and 3 are missing the boards necessary for the connection to the computer.  The parts were ordered a long time ago, but its possible they were "sucked to one of the sites" by Rolf (remember this is according to Jay).  They need to either track them down in Downs (possibly they're floating around and were just confused by the recent move), get them sent back from the sites, or order new ones (I was told by one person that the place they order from them notoriously takes a long time, sometimes up to 6 weeks.  I don't know if this is exaggeration or not...).  Other than the missing parts, they still need to wire up the fans and install new momentary power switches (apparently the Dolphin boards want momentary on/off buttons).  Otherwise, they're done.

We are due another CPU, just need to figure out which one it was in the test stand.

6 more BIO boards are done.  When I went over the plans with Jay, we realized we needed 7 more, not 6, so they're putting another one together.  Some ADC/DAC interface boards are done.  I promised to do another count here, to determine how many we have, how many we need, and then report that back to Jay before I steal the ones which are complete.  Unfortunately, he did not have a new drawing for the ASC/vertex wiring, so we don't have a solid count of stuff needed for them.  I'll be taking a look at the old drawings and also looking at what we physically have.

I did get Jay to place the new LSC wiring diagram into the DCC (which apparently the old one never was put in or we simply couldn't find it).  Its located at: https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=10985

I talked briefly with Alex, reminded him of feature requests and added a new one:

1) Single part representing a matrix of filter banks

2) Automatic generation of Simulated shared memory locations and an overall on/off switch for ADC/DACs

3) Individual excitation and test point pieces (as opposed to having to use a full filter bank).  He says these already exist, so when I do the CVS checkout, I'll see if they work.

In that directory are FILTER.adl, GDS_TP.adl, MONITOR.adl.  Those are the templates.  We also discovered the timing signal at some point was changed from something like SYS-DCU_ID to FEC-DCU_ID, so I basically just need to modify the .adl files to fix the time stamp channel as well.  I basically need to do a CVS checkout, put the fixes in, then commit back to the CVS.  Hopefully I can do that sometime today.

I also brought over 9 Contec DO-32L-PE boards, which are PCIe isolated digital output boards which do into the IO chassis.  These have been placed above the 2 new computers, behind the 1Y6 rack.

15928   Wed Mar 17 09:05:01 2021 Paco, AnchalConfigurationComputers40m Control Room Changes
• Switched positions of allegra and donatella.
• While doing so, the hdmi cable previously used by donatella snapped. We replaced this cable by another unused cable we found connected only on one end to rossa. We should get more HDMI cables if that cable was in use for some other purpose.
• Paco bought a bluetooth speaker/mic that is placed infront of allegra and it's usb adapter is connected to iMac's keyboard in the bottom. With the new camera installed, the 40m video call environment is now complete.
• Again, we have placed allegra's monitor for place holder but it is not working and we need new monitors for it in future whenever it is going to be used.
16027   Wed Apr 14 13:16:20 2021 AnchalConfigurationComputers40m Control Room Changes
• I have confirmed that the old two monitors' backlighting is not working. One can see the impression of the display without any brightness on them. Both old monitors are on the shelf behind.
• Today we got a monitor and mouse from Mike. I had to change /etc/default/grub GRUB_GFXMODE to 1920x1200@30 on allegra for it to work with the(any) monitor.
• Allegra is Debian 10 with latest cds-workstation installed on it. It is a good test station to migrate our existing scripts to start using updated cds-workstation configuration.
 Quote: Again, we have placed allegra's monitor for place holder but it is not working and we need new monitors for it in future whenever it is going to be used.

7670   Mon Nov 5 13:28:15 2012 jamieUpdateGeneral40m DCC document tree

Link to the new 40m DCC Document Tree: E1200979

6034   Tue Nov 29 07:45:56 2011 rana, joshSummaryComputer Scripts / Programs40m Daily News web pages

As part of the initiative to get a good daily summary page for aLIGO commissioning, Josh is spearheading his Detector Characterization group to produce such web pages for the 40m.

They're starting out with this launching point and then we can add all kinds of other information and plots as we want (e.g. Vac, PEM, Weather, coffee status). If you have suggestions/ideas, just edit this entry and add them, or email Josh directly.

1213   Fri Jan 2 17:20:44 2009 ranaSummaryComputer Scripts / Programs40m GWINC
I have made a '40m' directory in the iscmodeling CVS tree which allows one to run a 40m version of GWINC.

As does the previous one, it takes the default advLIGO config file and modifies some of the struct parameters
to make it appropriate for the 40m.

To make it run, I have added susp1.m to the GWINC directory. This calculates suspension thermal noise using
the Gonzalez-Saulson method that was later extended to
mirrors by Y. Levin. This is also the code used in the LIGO Noise Budget at the sites.

The previous code was giving a much larger value for thermal noise (probably because I didn't understand how
to use it right). It was based on a SURF report from '99.

Since we will have a mixture of MOSs and SOSs in the arms, I have just used SOSs in the model. So the suspension
thermal noise is overestimated by ~sqrt(2) (and realistically its uncertain by a much larger factor).

Since the new code now uses GWINC, the mirror and coating thermal noise are now more correct and use the
coherent therm-optic noise picture.

The 2 page PDF file shows the noise for 0 deg and 90 deg tuning of the SRC.

Although it looks like, from this plot, that we could measure coating thermal noise at the 40m, in reality we would have
to fix all of the technical noise sources first. Just the coil driver noise is probably at the level of 3 x 10^-17 m/rHz
at 100 Hz.
Attachment 1: bench40.pdf
1998   Thu Sep 24 19:35:20 2009 ranaHowToPhotos40m Google account

I've created a 40m Google account. Please post all the 40m related photos to this site. If you don't already have it, download Picasa to make this easier.

6895   Fri Jun 29 13:11:31 2012 steveUpdateVAC40m IFO at atm

The 4 hrs vent plot at 3 torr/min rate.

Nitrogen was used from 1e-6 torr to 35 torr  at intake pressure 14 PSI

The rest was filled with 5 cylinders of Instrument Grade Air at intake pressure 14 PSI

We can start opening chamber at 3 pm today

Attachment 1: vent06292012.png
Attachment 2: 40m@ATM.png
9571   Thu Jan 23 13:23:10 2014 SteveUpdateVAC40m IFO is at atmosphere

 Quote: There is BLANK VacControl_BAK.adl screen only.  I can move a valve by disconnecting it's  solenoid power if it's position is normally open. I will close V1 and check computer cable connections and move on with manual - hand disconnect ea valve to be moved into the right position for vent. Valve positions will be confirmed by looking manual indicators on valves.

The 40m vacuum envelope vent is completed with instrument grade air.

Valve configuration: chamber open, RGA is pumped through VM3 by TP3,

ELOG V3.1.3-