Since Nodus is a Solaris machine it can barely handle doing the ImageMagick commands (such as convert and import). I removed the auto MEDM snapshot routine from it
awhile ago and I think the rate of ELOGD crashes has decreased, although its not definitive.
The snapshots have now been re-actived to run on MAFALDA, after I fixed the absolute pathnames in the scripts and installed (via yum) the packages that mafalda
needed to run this (Xvfb, openmotif, compat, etc.). The snapshots web page is now refreshing by itself and the statScreen/cronjob.sh is running on mafalda 5x per hour.
The four IOO PZTs have been turned on in order to confirm the alignment of the IFO.
Once they are turned on, the spots (ITMX/ITMY/PRM/SRM) on the REFL CCD have been easily found.
When the X-arm was aligned to the green beam, it is easily locked to TEM00. Also some LG modes were visible.
i.e. There is some room to improve the mode matching.
The transmitted green at the PSL table is a bit too high and clipped by the first mirror on the table.
No IR flashes were found in either arms.
The below are the range and the set values of the strain gauge readback for the PZTs.
When the closed loop buttons are activated the PZTs are fixed at those values, if no one touches the set point dials.
Min Max SetP | Display on the module
PZT1 Yaw 2.20 9.95 6.08 | Broken
PZT1 Pitch -0.011 8.89 4.40 | 1.58
PZT2 Yaw 0.737 9.94 5.37 | 2.17
PZT2 Pitch 0.010 9.42 4.71 | 1.89
I came in today to check up on the StripTool and burn the Ubuntu LTS (new CDS OS) DVD. I was pretty excited to see the PRM flashes on Mon1.
I waggled the PRM/BS alignments and got a good contrast MICH and then bright flashes in the PRM that totally overload Mon1's CCD.
Now I can see flashes of some IR junk in the X Arm; its way off on the left edge of the mirror, but there's a beam.
For the short term, we can hook up the IO PZTs to some old EPICS channels (like one of the AUX guys in the LSC area), but eventually it has to get hooked up to the new ASC or ASS. We have to bug Joe to see where this shows up in his master diagram.
**Note: if you get lost sometimes when doing the alignments, remember that you can use time_machine_conlog.
rossa:general>./time_machine_conlog 2010/12/31,11:00:00 PDT C1:SUS-ITMX_PIT_COMM
Issuing the conlog command:
/cvs/cds/caltech/conlog/bin/conlog +epics -interp at 2010/12/31,11:00:00 PDT "C1:SUS-ITMX_PIT_COMM"
LIGO controls: values at 2010 12/31 11:00:00 pst
Attached is the last 8 days of Vacuum Pressure trend which includes the pumpdown.
Here is the list for the daytime tasks of tomorrow, Jan. 12th.
The daytime task is a work basically to be done or quitted before the sun goes down.
Along with the tasks, we roughly assigned the people who are responsible for it.
The tasks below are basically separated from each other, so we can work in parallel.
* check whitening filter
* demodulation board check
* check ADC connections
* fix binary outputs.
* FM9 must be the trigger of the binary outputs instead of FM10.
* investigate why the depth is so low
* change the name of seismic channels properly so that we can deal with the calibrated stuff
* make screens
I'll be gone to Hanford site next week and come back to Caltech on 24th's week.
I setup a standalone RT system at the desk around circuit stock in the 40m.
Please leave this setup until I come back. I'll keep working when I come back.
I found Tara's elog entry that Jenne laser is at PSL Lab.
Since we recently use it frequently, we should be aware where it is now.
The Vertex crane is smarter and safer now. This upgrade ensures that the two sections of I-beam (8ft, 4ft) remain firmly latched to form a straight member till the latch is released.
In specific, it ensures that problems such as this one do not occur in the future.
The new safety features are:
When the I-beam sections are latched together, a pneumatic piston ensures that the latch is secure.
If the latch is not engaged the trolley does not move outward beyond the end of the 8-foot section of the I beam.
If the trolley is out on the 4-foot section of the beam then we cannot disengage the latch.
How does it work?
The state of the Limit Switch 1 changes when the trolly goes past it. The Limit Switch 2 gets pressed when the two sections are latched together.
The pneumatic piston raises or lowers the latch. The Pneumatic Latch Switch operates a pneumatic valve controlling the state of the piston.
The new controller now has Pneumatic Latch Switch in addition to the usual Start, Stop, Up, Down, In and Out buttons.
Each of the Up, Down, In and Out buttons have two operational states: Half pressed (low speed) and Full pressed (High Speed). Their functions remain the same as before.
The new Pneumatic Switch:
When this switch is 'Engaged' and the 4 ft section is swung in-line with the 8 ft section, the two sections get latched together.
To unlatch them we have to throw the switch into the 'Disengage' state. This makes the piston push the latch open and a spring rotates the 4 ft section about its pivot.
Limit Switch 2 is not pressed (I-beams not aligned straight) ==> Limit Switch 1 will prevent the trolley from out going beyond the 8 ft section.
While Limit Switch 2 is pressed we cannot disengage the latch.
The pneumatic piston requires 80psi of pressure to operate. However we have only 40psi in the lab and the piston seems to operate quite well at this pressure as well. I believe a request has been made to get an 80psi line laid just for this application.
The projector in the controls room has been fixed the orange blinking of the status LED.
What we needed was to push "Volume -" and "Menu" for 5 sec.
This resets the timer of the lamp. When the timer reaches 2500 hours, it automatically start sabotaging.
We've got the spare lamp. It is in the top drawer of the computer cabinet on which the label makers are.
The south arm labels were changed from y to x to reflect reality.
So racks, manual disconnects and breakers now have their actual name. The east arm will be changed over tomorrow.
Please remove incorrect labels if you see any !
I can not find 1X4 breaker so it will be traced.
Jenne found the X-end table enclosure had been left open. She replaced the lid on it.
I think this week is going to be an "alignment week".
The goal is to get a good alignment on X arm for both the green and the IR beam in order to reduce a2l couplings.
Today's missions are :
- fixing the oplev channel names (see here)
- fixing the oplev gain issue (see here)
- engage the oplev servos
- f2p adjustment
- make a realtime lockin model for the f2p measurement and the dithering technique
- alignment of the MC incident beam (because we installed a new PMC this morning)
- manual alignment of the IR beam by steering PZT1 and PZT2 (this procedure will be replaced by an automatic way soon)
- bounce roll filters (see here)
. mode matching for MC (Jenne/Koji)
. mode matching for doubling crystal on PSL table (Suresh/Koji)
. f2p adjustment (Kiwamu)
. fix daq and CDS issues (Joe)
. increase oplev gain (low priority)
. make ITMY camera nicer (Steve)
. c1ass simlink model (Valera/Joe)
. Bounce Roll notches (Suresh)
. align everything (at first green beam, then X arm cavity and finally IR beam)
. update the noise spectrum of the green locking
. estimate the noise from angle to length coupling
- more precise F2P measurement and modify lockin simlink model (Kiwamu)
- run C1ASS to check it (Valera)
- take care of CDS (Joe)
- MC mode matching (Jenne/Koji)
- RF stuff (Suresh)
- mode matching for doubling crystal at PSL table (low priority)
- OPLEV (low priority)
- update the noise spectra of green locking
- make noise budgets
* mode matching
* epics LO HI values
* recover FSS
* make ISS working
- Put priority on the list
- Put names on the items
- Where is the CDS TO DO ==> Joe
- Remote disconnection of the greeen PDH
- What is the situation of the PD DC for the LSC PDs?
- SUS Satelite box Resister replacement ==> Jamie
- IMC mode matching ==> Jamie/Larisa
- Mechanical shutters everywhere
- SRM OPLEV Connection
- MC OAF
- Better LSC whitening boards
1) Get ETMY working - figure out why signals are not getting past the AI board (D000186) to the coils.
2) Get TDS and command line AWG stuff working
3) Get c1ass and new c1lsc (with Koji) fully integrated with the rest of the system.
4) Get CDS software instructions up to date and well organized.
5) Redo cabling and generally make it a permanent installation instead of hack job:
a) Measure cable lengths, check connectors, wire with good routes and ensure strain relief. Ensure proper labeling
b) Get correct length fiber for c1sus RFM and timing.
c) Fix up final BO adapter box and DAC boxes.
d) Make boxes for the AA filter adapters which are currently just hanging.
e) Get two "faceplates" for the cards in the back of the ETMY IO chassis so they can screwed down properly.
f) Remove and properly store old, unused cables, boards, and anything else.
6) Create new documentation detailing the current 40m setup, both DCC documents and interactive wiki.
7) Setup an Ubuntu work station using Keith's wiki instructions
1)Create simulated plant to interface with current end mass controls (say scx).
2) Create proper filters for pendulum and noise generation, test suspension.
3) Propagate to all other suspensions.
4) Working on simulated IFO plant to connect to LSC. Create filters for near locked (assume initial green control perhaps) state.
5) Test LSC controls on simulated IFO.
6) Fix c code so there's seamless switching between simulated and real controls.
Here is a partial list of stuff which is being packed at LLO to be shipped to CIT. The electronics ckt boards are yet to be added to this list. Will do that tomorrow.
New Focus Servo Controller has just arrived. We have 25 days to evaluate this product.
It will have to be shipped back to the vendor on April 4, 2011 the latest in order to get full refund.
Just for a record. We got 4 new laser pointers (2 greens, 1 blue, and 1 green and red combination). Don't lose them.
They reside in a bucket on the SP table, where IR viewers and sensor cards also reside.
This is the grand plan we talked about in the beginning of the meeting.
* Temporary strain relief for the heliax cables on 1X2 (Steve)
* RF diagrams and check lists (Suresh)
=> In the lunch meeting we will discuss the details about what we will do for the RF installation.
* Electronics design and plan for Green locking (Aidan / Kiwamu)
=> In the lunch meeting we will discuss the details.
* LSC model (Koji)
* Video cable session (team)
* LPF for the laser temperature control (Larisa)
[Steve / Kiwamu]
As a part of the video cable session, we reconnected some power cords on 1Y1 rack.
During the work we momentarily turned off c1aux, which handles DMF, Illumintators, mechanical shutters and the old video epics.
I think it automatically reverted the things, but we may need to check them.
I strain relieved RF cables labeled 33 MHZ LO and 166 MHZ to EOM at 1X2 This is a temporary setup for the 11 MHZ
The coax N bulkheads connectors are mounted on the plastic front panel now.
They reside in a bucket on the SP table, where IR viewers and sensor cards also reside.
Low power green-red laser pointers are in. High power green, red and blue pointers are confiscated.
The steps from this elog were followed.
In addition, I did a burt restore of c1sus, c1mcs.
I then swapped all the gain settings from ITMX to ITMY, and reenabled the watchdogs.
I did some basic kick tests (1000 counts into UL coil) and confirmed channels like C1:SUS-ITMX_ULPD_VAR (watchdogs mV readback) corresponded to the correct optic. I also checked that the POS, PIT, YAW, SIDE produced reasonable damping when engaged.
Currently the c1scy, c1mcs, and c1rfm models are reporting an error with receiving some data sent over the GE Fanuc Reflected memory cards.
To be more exact, the C1:SUS-ETMY_ALS signal from the c1gcv FE code on the c1ioo computer going too the Y end is not being received. However, the C1:SUS-ETMY_LSC signal is. So the physical RFM card seems to be working.
Similarly, the TRY signal is being sent correctly from the Y end computer. The X end is working fine and receiving both LSC and ALS signals.
The c1mcs and c1rfm models also receive data from the c1ioo computer and reporting receiving errors.
Because the RFM cards are transmitting and receiving at least some channels, I'm guessing there was changes made to the C1.ipc file, which defines the memory locations of these various channels on the RFM network, and that when a model was rebuilt, a different one using the previous IPC file was not, and thus one of the computer is going to the wrong place to either read or write data.
Tomorrow, I'm planning on the following:
1) Clean out the C1.ipc file (/opt/rtcds/caltech/c1/chans/ipc/)
2) Rebuild all models
3) Run activate_daq.py script
4) Restart models via script
If this doesn't clear up the problem, I'll continue to bug hunt.
The attached plot shows 2 day trends of the PMC and MC reflected and transmitted power, the PSL POS/ANG QPD signals, and the temperature measured by the dust counter.
The power step in the middle of the plot corresponds to Koji/Jenne PMC realignment yesterday.
It looks like everything is following the day/night temperature changes.
Minicircuits ERA-5SM was used for the RF amp of the BBPD. This amp is promising as a replacement of Teledyne Cougar AP389
as ERA-5SM gave us the best performance so far among the BBPDs I have ever tested for the aLIGO BBPD/Green.
The -3dB bandwidth of ~200MHz and the noise floor at the shotnoise level of 0.7mA DC current were obtained.
The aLIGO BBPD candidate (LIGO Document D1002969-v7) employs Teledyne Cougar AP389 as an RF amplifier.
This PD design utilizes the 50Ohm termination of the RF amp as a transimpedance resistance at RF freq.
However, it turned out that the bandwidth of the transimpedance gets rather low when we use AP389, as seen in the attachment2.
The amplifier itself is broadband upto 250MHz (the transfer function was confirmed with 50Ohm source).
The reason is not understood but AP389 seems dislike current source. Rich suggested use of S-parameter measurement
to construct better model of the curcuit.
On the other hand, the RF amplifiers from Minicircuits (coaxial type like ZFL-1000LN+), in general, exhibit better compatibility with PDs.
If you open the amplifier case, you find ERA or MAR type monolithic amplifiers are used.
So the question is if we can replace AP389 by any of ERA or MAR.
- The large gain of the RF amp is preffered as far as the output does not get saturated.
- The amplifier should be low noise so that we can detect shot noise (~1mA).
- The freq range of the useful signal is from 9MHz to 160MHz.
The advanced LIGO BBPD is supposed to be able to receive 50mW of IR or 15mW of 532nm. This approximately corresponds to
5mA of DC photocurrent if we assume FFD-100 for the photodiode. At the best (or worst) case, this 5mA has 100% intensity modulation.
If this current is converted to the votage through the 50Ohm input termination of the RF amp, we receive -2dBm of RF signal at maximum.
This gives us a dilemma. if the amp is low noise but the maximum output power is small, we can not put large amount of light
on the PD. If the amp has a high max output power (and a high gain), but the amp is not low noise, the PD has narrow power range
where we can observe the shotnoise above the electronics noise.
What we need is powerful, high gain, and low noise RF amplifier!
Teledyne Cougar AP389 was almost an ideal candidate before it shows unideal behavior with the PD.
Among Minicircuits ERA and MAR series, ERA-5 (or ERA-5SM) is the most compatible amplifier.
Considering the difference of the gain, they are quite similar for our purpose. Both can handle upto -2dBm,
which is just the right amount for the possible maximum power we get from the 5mA of photocurrent.
A test circuit has been built (p.1 attachment #1) on a single sided prototype board.
First, the transfer function was measured with FFD-100. With the bias 100V (max) the -3dB bandwidth of ~200MHz was observed.
This decreases down to 75MHz if the bias is 25V, which is the voltage supplied by the aLIGO BBPD circuit. The transimpedance
at the plateau was ~400Ohm.
Next, S3399 was tested with the circuit. With the bias 25V and 30V (max) the -3dB bandwidth of ~200MHz was obtained although
the responsivity of S3399 (i.e. A/W) at 1064nm is about factor of 2 smaller than that of FFD-100.
The noise levels were measured. There are many sprious peaks (possibly by unideal hand made board and insufficient power supply bypassing?).
Othewise, the floor level shows 0.7mA shotnoise level.
The RF amplifier of the prototype BBPD has been replaced from ERA-5SM to MAR-6SM.
The bandwidth is kept (~200MHz for S3399 with 30V_bias), and the noise level got better while the maximum handling power was reduced.
MAR-6SM is a monolithic amplifier from Minicircuits. It is similar to ERA-5SM but has lower noise
and the lower output power.
The noise floor corresponds to the shotnoise of the 0.4mA DC current.
Now the mess below 50MHz and between 90-110MHz should be cleaned up.
They are consistently present no matter how I change the PD/RF amp (ERA<->MAR)/bias voltage.
I should test the circuit with a different board and enhanced power/bias supply bypassing.
- Assume 5mA is the maximum RF (~50mW for 1064nm, ~15mW for 532nm). This is already plenty in terms of the amount of the light.
- 100% intenisty modulation for 5mA across 50Ohm induces -2dBm RF power input for the amplifier.
- Assume if we use MAR-6 for the preamplifier. The max input power is about -18dBm.
This corresponds to 16% intensity modulation. It may be OK, if we have too strong intensity modulation, we can limit the power
down to 0.8mA in the worst case. The shot noise will still be above the noise level.
- In the most of the applications, the RF power is rather small. (i.e. 40m green beat note would expected to be -31dBm on the RF amp input at the higherst, -50dBm in practice)
So probably we need more gain. If we can add 10-12dB more gain, that would be useful.
- What is the requirement for the power amplifier?
Search result for Freq Range 10-200MHz / Max Gain 14dB / Max NF 15dB / Min Power Out 13dBm
GVA-81 is available at the 40m. ERA-4SM, ERA-6SM, HELA-10D are available at Downs.
Conversion between nV/rtHz and NF (in the 50Ohm system)
SN1: Connect signal source (50Ohm output) to a 50Ohm load.
Power ratio between the noise and the signal
SN1 = (4 k T (R/2)) / (S/2)^2
SN2: Connect signal source (50Ohm output) to an RF amp.
Only the voltage noise was considered.
SN2 = (4 k T (R/2) + Vn^2) / (S/2)^2
10 Log10(SN2/SN1) = 10. Log10(1 + 2.42 (Vn / 1nVrtHz)^2)
Vn: 0 nVrtHz ==> 0dB
Vn: 0.5 nVrtHz ==> 2dB
Vn: 1 nVrtHz ==> 5dB
Vn: 2 nVrtHz ==> 10dB
Vn: 3 nVrtHz ==> 13.5dB
- The BBPD circuit has been constructed on the aLIGO BBPD board
- It still keeps 200MHz BW with FDD-100 Si PD for the 100V bias.
- The noise spectrum has been cleaned up a lot more. It shows the noise level of the 0.4mA shotnoise between 9-85MHz.
The noise at 160MHz is the noise level of the 1mA shotnoise.
Some of the noise peaks at around 97MHz came from the bias voltage.
What to do next
- Confirmation of the performance with the original aLIGO BB PD configuration.
- Notch filter for 9MHz (for aLIGO).
- Implementation of a power amplifier. (issues: power supply and heat removal)
I found ITMX-ISCT and BS-ISCT ( IFO sensing-control table) not covered this morning. Please do not leave tables open.
I have made my own AutoCAD WS account and put the latest 40m layout.
AutoCAD WS is a free cloud service which enable us to browse/edit the DWG files.
You can view/play/print it from the following link even without making the account.
If you make your account you can actually save it although the editing capability is somewhat limited.
- It needs the Flash plug-in and Internet connection.
- I think Safari is the most stable platform on Mac. (i.e. I had some malfunctions with Firefox and Chrome)
Here is the conclusive result for the circuit configuration for aLIGO BBPD and 40m Green PD.
- Use Mini-circuits MAR-6SM for the RF preamplifier. The 50Ohm input impedance is used for the RF transimpedance.
The maximum output is ~4dBm.
- Use Mini-circuits GALI-6 for the RF middle power amp. The gain is 12dB and the amplifier is linear up to +17dBm. i.e. This is still linear at the maximum output level of MAR-6SM.
- The total RF transimpedance is ~2k. The DC transimpedance is also 2k.
- The bandwidth is 80MHz with FFD100 and internal 25V bias. When S3399 is used, the bandwdith goes up to 180MHz
although the responsivity of FFD100 at 1064nm is better than S3399 by a factor of 1.5. At the 40m we will use S3399 for the green BB PD.
- By adding an LC network next to the PD, one of the unnecessary signal can be notched out.
As an example, 9MHz notch was placed for the FFD100 case.
- Noise level: ~10pA/rtHz as a floor noise level at around 30MHz. This corresponds to the equivalent dark current of 0.4mA.
Matt has finished the PCB layout. We will order small first batches, and stuff it for the test. Some of these will be the 40m green PD.
[Jenne / Kiwamu]
We spent approximately an hour for the weekly Wednesday cleaning.
This time we moved onto an area where a desk and optics shelf reside along the Y arm.
We will continue cleaning up there in the next time too.
This is the new hot air station for the 40m lab.........
Kiwamu and I have started to put together a vent plan on the 40m wiki:
We will keep working on this (there's still a *lot* to fill in), but please help fill in the plan by adding questions, answers, procedures, preparations, etc.
I put a paper Peet's bag with half of the Mini-Moos into George.
Summary for the week ending June 26th. (Number of elog entries = 53)
Photo diodes stored in the east arm cabinet E4: ALL PDs meet here, fast or slow......
Summary of the week ending July 3rd. Number of elog entries = 44
Please ask the owner unless it is rotten. Do not put food into garbage can inside. Take them outside so you are not inviting ants !
Each bottle has matched seals. They are not interchangeable.
It is critical that the solvent do not reach the rubber bulb. Practice with the pipet.
In case of solvent touching the suction bulb: do not let the solvent go back into the bottle! Remove bulb, let it dry out and rinse pipet.
It is essential that the solvent bottle must be rinsed and refilled if it's content met with the rubber bulb.
Use glass syringe with SS needle in critical application: Hamilton ~0.1 ml
Please return sensor card to laser log box so others can use it. We have only one larger fluorescent sensor card.
Summary of the week ending July 10th. Number of elog entries = 21
+ The cutoff frequency of the high pass filters for the damping were set to 30Hz.
+ Turned off all the BounceRoll filters.
+ The BS oplev was checked and seemed healthy.
+ All the measred data of the LSC whitening filters were fit.
+ All the zpk parameters are recorded on the wiki.
+ The setup completed.
+ The freqeucy-lock of the ABSL laser was achieved with UGF of ~ 40kHz.
+ The temperature of the ABSL laser was adjusted to be 47.25 deg
+ The I-P curve of the ETMY laser was measred.
+ The current set point is 1.8 [A], which used to be 1.5 [A], corresponding to the output of power of 197 [mW] and 390 [mW] respectively.
Summary of the week ending July 17th. Number of elog entries = 20