Koji and Kevin measured the vertical beam profile of the Innolight 2W laser at one point.

This data was taken with the laser crystal temperature at 25.04°C and the injection current at 2.092A.

The distance from the razor blade to the flat black face on the front of the laser was 13.2cm.

The data was fit to the function y(x)=a*erf(sqrt(x)*(x-x0)/w)+b with the following results.

Reduced chi squared = 14.07

x0 = (1.964 +- 0.002) mm

w  = (0.216 +- 0.004) mm

a  = (3.39  +- 0.03) V

b  = (3.46  +- 0.03) V

Back in Gainesville in 1997, I learned how to do this using the chopper wheel. We had to make the assumption that the wheel's blade was moving horizontally during the time of the chop.

One advantage is that the repetitive slices reduces the random errors by a lot - you can trigger the scope and average. Another advantage is that you can download the average scope trace using USB, floppy, or ethernet instead of pencil and paper.

But, I never analyzed it in enough detail to see if there was some kind of nasty systematic error.

Good fit. I assumed sqrt(x) is a typo of sqrt(2).

 What kind of fit did you use? How are the uncertainties in the parameters obtained?

When I got back from lunch just now, I noticed that the PMC TRANS and REFL cameras were showing no spots. I went onto the PSL table, and saw that the NPRO was in fact turned off. I turned it back on.

The laser was definitely ON when I left for lunch around 130pm, and this happend around 140pm. Anjali says no one was in the lab in between. None of the FEs are dead, suggesting there wasn't a labwide power outage, and the EX and EY NPROs were not affected. I had pulled out the diagnostics connector logged by Acromag, I'm restoring it now in the hope we can get some more info on what exactly happened if this is a recurring event. So FSS_RMTEMP isn't working from now on. Sooner we get the PSL Acromag crate together, the better...

Happened again at ~730pm.

The NPRO diag channels don't really tell me what happened in a causal way, but the interlock channel seems suspicious. Why is the nominal value 0.04 V? From the manual, it looks like the TGUARD is an indication of deviations between the set temperature and actual diode laser temperature. Is it normal for it to be putting out 11V?

I'm not going to turn it on again right now while I ponder which of my hands I need to chop off.

After discussing with Koji, I turned the NPRO back on again, at ~4PM local time. I first dialled the injection current down to 0A. Then powered the control unit state to "ON". Then I ramped up the power by turning the front panel dial. Lasing started at 0.5A, and I saw no abrupt swings in the power (I used PMC REFL as a monitor, there were some mode flashes which are the dips seen in the power, and the x-axis is in units of time not pump current). PMC was relocked and IMC autolocker locked the IMC almost immediately.

Now we wait and watch I guess.

NPRO shutoff at ~1517  local time today afternoon. Again, not many clues from the NPRO diagnostics channel, but to my eye, the D1_POW channel shows the first variation from the "steady state", followed by the other channels. This is ~0.1 sec before the other channels register some change, so I don't know how much we can trust the synchronizaiton of the EPICS data streams. I won't turn it on again for now. I did check that the little fan on the back of the NPRO controller is still rotating.

gautam 10am 4/29: I also added a longer term trend of these diagnostic channels, no clear trends suggesting a fault are visible. The y-axis units for all plots are in Volts, and the data is sampled at 16 Hz.

I suggested in an earlier elog that after the repair of the NPRO, the PZT capacitance may have changed dramatically. This seems unlikely - I measured the PZT capacitance with the BK Precision LCR meter and found it to be 2.62 nF, which is in excellent agreement with the numbers from elogs 3640 and 4354 - but this makes me wonder how the old setup ever worked. If the PZT capacitance were indeed that value, then for the Pomona box design in elog 4354, and assuming the PM at ~216kHz which was the old modulation frequency was ~30rad/V as suggested by the data in this elog, we would have had a modulation depth of 0.75 if the Function Generator were set to output a Signal at 2Vpp (2Vpp * 0.5 * 0.05 * 30rad/V = 1.5rad pp)! Am I missing something here?

Instead of using an attenuator, we could instead change the capacitor in the pomona box from 47pF mica to 5pF mica to realize a modulation depth of ~0.2 at the new modulation frequency of 231.25 kHz. In any case, as elog 4354 suggests, the phase introduced by this high-pass filter is non-zero at the modulation frequency, so we may also want to install an all-pass filter which will allow us to control the demodulation phase. This should be easy enough to implement with an Op27 and passive components we have in hand...

Innolight 1W 1064nm, sn 1634 was purchased in 9-18-2006 at CIT. It came to the 40m around 2010

It's diodes should be replaced, based on it's age and performance.

RIN and noise eater bad. I will get a quote on this job.

The Innolight Manual frequency noise plot is the same as Lightwave' elog 11956

I don't think there's any evidence that the noise eater is bad. That would change the behavior of the relaxation oscillation which is at 1 MHz ?

While I was investigating the AM/PM ratio of the Innolight, I found that there was a pronounced peak in the RIN at ~400kHz, which did not change despite toggling the noise eater switch on the front panel (see plot attached). The plot in the manual suggests the relaxation oscillations should be around 600kHz, but given that the laser power has dropped by a factor of ~3, I think it's reasonable that the relaxation oscillations are now at ~400kHz? 

It is strange that there is no difference between with and without NE, isn't it?

The Innolight laser control unit has a 25 pin D-sub connector on the rear which is meant to serve as a diagnostics aid, and the voltages at the various pins should tell us the state of various things, like the diode power monitor, laser crystal TEC error temperature, NE status etc etc. Unfortunately, I am unable to locate a manual for this laser (online or physical copy in the filing cabinets), so the only thing I have to go on is a photocopied page that Steve had obtained sometime ago from the manual for the 2W NPRO. According to that, Pin 1 is "Diode laser 1, power monitor, 1V/W". The voltage I measured (with one of the 25 pin breakout boards and a DMM) is 1.038V. I didn't see any fast fluctuations in this value either. It may be that the coefficient indicating "normal" state of operation is different for the 1W model than the 2W model, but this measurement suggests the condition of the diode is alright after all?

I also measured the voltage at Pin 12, which is described in the manual as "Noise Eater, monitor". This value was fluctuating between ~20mV and ~40mV. Toggling the NE switch on the front of the control unit between ON and OFF did not change this behaviour. The one page of the manual that we have, however, doesnt provide any illumination on how we are supposed to interpret the voltage measured at this pin...

This is the same one as what you got from Steve. But you can find full pages.

https://wiki-40m.ligo.caltech.edu/PSL/NPRO

It shipped out for repair evaluation.

Arrived to Hayward,CA   2016Feb16

 We decided to rename the Input Beam channels (while keeping temporary backwards compatible aliases) as:

C1:ASC-IB_POS_X, C1:ASC-IB_POS_Y, C1:ASC-IB_ANG_SUM, etc.

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.

The summary pages are now online (Daily Summary), and will eventually be found on the 40m Wiki page under "LOGS-Daily Summary". (Currently, the linked website is the former summary page site)

Currently, all of the IFO and Acoustic channels have placeholders (they are not showing the real data yet) and the Weather channels are not working, although the Weather Station in the interferometer room is working (I am looking into this - any theories as to why this is would be appreciated!!).

I am looking for advice on what else to include in these pages.  It would be fantastic if everyone could take a moment to look over what I have so far (especially the completed page from July 23, 2012) and give me their opinions on:

1.  What else you would like to see included

2.  Any specific applications to your area of work that I have overlooked

3.  What the most helpful parts of the pages are

4.  Any ways that I could make the existing pages more helpful

5.  Any other questions, comments, clarifications or suggestions

Finally, are the hourly subplots actually helpful?  It seems to me like they would be superfluous if the whole page were updating every 1-2 hours (as it theoretically eventually will).  These subplots can be seen on the July 24, 2012 page.

My email address is endavison@umail.ucsb.edu.

 Thank you!  

When I came in this afternoon, I saw that the PZT voltage to the PMC had railed. Following the usual procedure of turning the servo gain to zero and adjusting the DC offset, I got the PMC to relock, but the PMCR level was high and the alignment looked poor on the control room monitor. So I tweaked the input alignment on the PSL till I felt it was more reasonable. The view on the control room monitor now looks more like the usual state, and the "REFL (V)" field on the PMC MEDM screen now reads 0.02-0.03 which is the range I remember it being in nominally. 

I turned on the power supplies for the output PZTs and pitch and yaw for PZT2.  This is back to the condition that we had during atmosphere alignment, so after Ayaka has finished tweaking the MC, we can have a look at alignment of the interferometer.

Checking the drift in input pointing (TT2 is the main suspect)

I have centered IPPOS and the 2/3 part of IPANG that comes out of vacuum to the QPDs to see the drift in input pointing over the weekend or atleast overnight.

If anybody would be working with the IFO alignment over the weekend, do so only after recording the drift in IPANG and IPPOS or if you will be working later tonight, center them ion the QPDs before leaving.

I centered ipang and ippos on the QPDs (using only the steering mirrors) and wanted to see the drift over the weekend.

Observation
1. IPANG has drifted (QPD sum changed from -6 to -2.5); but it is still on the QPD.
2. IPPOS does not show any drift.
3. In the plot: The jump in IPANG on the left occured when I centered the beam to the QPD and that on the right is from the 4.7 earthquake and its aftershocks this morning.

Follow-up questions
1. Do we need to worry about this drift?
2. Which of the two TTs is resposible for the drift?
3. Do the TTs tend to drift in the same direction everytime?

P.S. The TTs were not touched to center on IPANG and IPPOS. The last time they were touched was nearly 6 hours before the centering. So the question of any immediate hysteresis is ruled out.

[Jenne, Manasa, Yuta]

We temporarily centered the beam on IPANG to see input pointing drift. From eyeball, drift was ~ 0.1 mrad/h in pitch.

What we did:
  1. Aligned TT1/TT2 and aligned input pointing to Yarm.

  2. Tweaked TT2 in pitch to center the beam on the first steering mirror of IPANG path. We still saw Yarm flash in higher order modes at this point. Before tweaking, the beam was hitting at the top edge.

  3. Centered the beam on IPANG QPD.

  4. Moved IPPOS first steering mirror because IPPOS beam was not on the mirror (off in yaw, on mirror edge). Also, IPPOS beam was coming out clipped in yaw.

  5. Centered the beam on IPPOS QPD. We put lens in the path to focus the beam on the QPD.

  6. Left input pointing untouched for 4 hours.

  7. Restored TT2 again. We tried to align Y arm with IPANG available, but it was not possible without touching TRY path and AS was also clipped.

Result:
  Below is the trend of IPANG sum, X, and Y. IPANG Y (IBQPD_Y) drifted by ~0.8 counts in 4 hours. IPANG is not calibrated yet, but Jenne used her eyeball to measure beam position shift on IPANG steering mirror. It shifted by ~2 mm. This means, input pointing drifts ~0.1 mrad/h in pitch.


Discussion:
  Compared with yaw, pitch drift is quite large considering beam size at ETMY(~5 mm). We can monitor input pointing drift in weekends get longer trend.

Note:
  - IPANG and IPPOS are both changed from the state before pumping.

There is no beam going into the IFO at the moment. There was definitely a spot on the AS camera after I restored the suspensions yesterday, as you can see from the ASDC level in Attachment #1. But at around 2pm Pacific yesterday, the ASDC level has gone to 0. I suspect the TTs. There is no beam on the REFL camera either when PRM is aligned, and PRM's DC alignment is good as judged by Oplev.

Normally, I am able to recover the beam by scanning the TTs around with some low frequency sine waves, but not today. We don't have any readback (Oplev/OSEM) of the TT alignment, and the DC bias values havent jumped abnormally around the time this happened, judging by the OUT16 monitor points (see Attachment #2). The IMC was also locked at the time when this abrupt drop in ASDC level happened. Unfortunately, we don't have a camera on the Faraday so I don't know where the misalignment is happening, but the beam is certainly not making it to the BS. All the SOS optics (e.g. BS, ITMX and ITMY) are well aligned as judged by Oplev.

Being debugged now...

As suspected - the problem was with the TTs. I tested the TT signal chain by driving a low frequency sine wave using AWG and looking at the signal on an o'scope. But I saw nothing, neither at the AI board monitor point, nor at the actual coil driver mon point. I decided to look at the IOP testpoints for the DAC channels, to see if the signals were going through okay on the digital side. But the IOP channels were flatlined, as viewed on dataviewer (see Attachment #1). This despite the fact that the DAC output monitor screen in the model itself was showing some sensible numbers, again see Attachment #1.

Looking at the CDS overview screen, there were no red flags. But there was a red indicator sneakily hidden away in the IOP model's CDS status screen, the "DAC" field in the state word is red. As Attachment #2 shows, a change in the state word is correlated with the time ASDC went to 0.

Note that there are also no errors on the c1lsc frontend itself, judging by dmesg. I want to do a model restart, but (i) this will likely require reboots of all vertex FEs and (ii) I want to know if any CDS experts want to sniff for clues to what's going on before a model restart wipes out some secret logfiles. I'm a little confused that the rtcds isn't throwing up any errors and causing models to crash if the values are not being written to the registers of the DAC. It may also be that the DAC card itself is dead . To re-iterate, all the EPICS readbacks were suggesting that I am injecting a signal right up to the IOP.

Quoting from the runtime diagnostics note:

Below is the bottom view of the geophone preamplifier and controller for the STACIS. It slides into the upper part of the STACIS, under the blue platform. The geophone signal goes in the bottom left, gets amplified, filtered, and otherwise pampered, and goes out from the bottom right. From there it goes on to the high voltage amplifier, and finally to the PZT stacks. Below right is a closer view of the output port for the preamplifier, top and bottom.

I suggest de-soldering and bending up the pins that carry the geophone signal (so the signals don't go directly to the high voltage amplifier), and adding the circuit below between the preamp and amplifier. The preamp connector is still attached to the high voltage amplifier connector in this setup, only the geophone signal pins are disconnected.

More on the circuit and its placement:

The first op-amp is a summing junction, and the second is just a unity gain inverter so that signal doesn't go into the high voltage amplifier inverted. I tested this with the breadboard, and it seems to work fine (amplitudes of two signals add, no obvious distortion). The switches allow you to choose local feedback, external feedforward, or both.

The geo input will be wires from the preamp (soldered to where the pins used to go), and the external input will be BNC cables, with the source probably a DAC. The output will go to the bent up pins that used to be connected to the preamp (they go into the high voltage amplifier). This circuit can sit outside of the STACIS- there is a place to feed wires in and out right near where the preamplifier sits. For power, it can use the STACIS preamp supply, which is +/- 15V. The resistors I used in the breadboard test were 10 kOhm, and the op-amp I used was LT1012 (whose noise should be less than either input, see eLog 7190).

This is visually represented below, with the preamp pin diagram corresponding to the soldering points with the preamp upside down (top right picture):

[Jenne, Anamaria]

I put the new matricies in from the free swinging test for the: ITMX, ITMY, ETMX, ETMY, PRM, BS

Some of the optics damped okay, but ETMX and BS were not good at all.  ETMX was ringing up when I turned on the damping.  BS wasn't, but when I gave it a kick, it wouldn't damp.  No good.

I tried ITMY, and it was totally fine, with nice damping Qs of ~5.  So, I don't know what's going on. 

Anamaria is trying a new 4x4 matrix-inverter, so we can look at the inversion of just the face osems.  We'll see how it goes. 

Since things were crappy, I did a BURT restore, so things are as they were earlier this morning.

 After Kiwamu set the REFL11 phases in the PRMI configuration (maximized PRM->REFL11I reesponse) I tried to measure the MC length and the 11 MHz frequency missmatch by modulating the 11 MHz frequency and measuring the PM to AM conversion after the MC using the REFL11Q signal. The modulation appears in the REFL11Q with a good snr but the amplitude does not seem to go through a clear minimum as the 11 MHz goes through the MC resonance.

We could not relock the PRMI during the day so I resorted to a weaker method - measuring the amplitude of the 11 MHz sideband in the MC reflection (RF PD mon output on the demod board) with a RF spectrum analyzer. The minimum frequency on the IFR is 11.065650 MHz while the nominal setting was 11.065000 MHz. The sensitivity of this method is about 50 Hz.

As promised some time ago, I've obtained input noise spectra from the sites calibrated to physical units. They are located in a new subdirectory of the BHD repo: A+/input_noises. I've heavily annotated the notebook that generates them (input_noises.ipynb) with aLOG references, to make it transparent what filters, calibrations, etc. were applied and when the data were taken. Each noise term is stored as a separate HDF5 file, which are all tracked via git LFS.

So far there are measurements of the following sources:

• L1 SRCL
• H1 SRCL
• L1 DHARD PIT
• L1 DSOFT PIT
• L1 CSOFT PIT
• L1 CHARD PIT

These can be used, for example, to make more realistic Hang's bilinear noise modeling [ELOG 15503] and Yehonathan's Monte Carlo simulations [ELOG 15539]. Let me know if there are other specific noises of interest and I will try to acquire them. It's a bit time-consuming to search out individual channel calibrations, so I will have to add them on a case-by-case basis.

One factor which hampers locking efforts is the apparent drift of the input beam into the IFO. Over timescales of ~1 hour, I have noticed that the spot on the AS camera drifts significantly (~1 spot size) in pitch. The IPPOS QPD bears out this observation, see Attachment #1. The IMC WFS control signals do not show a correlated drift, hence my claim that the TTs are to blame.

I am able to correct this misalignment by moving TT1 in pitch (see Attachment #2, which shows some signals from a ~1 hour PRMI lock, during which time the pointing drifted, and I corrected it by moving TT1 pitch). Assuming the problem is purely TT1 pitch drifting, this corresponds to 3mm / 6m ~500urad of shift in 1 hour - seems very large. The fact that the drift is only present in pitch and doesn't really show up in yaw makes me think the problem is likely mechanical (unless the voltage to the top two coils is drifting relative to the bottom, but no LR drift, which would be very coincidental). At the moment, this is just an annoyance, but it'd be good for this problem to be fixed.

I haven't yet figured out how to make ndscope export these plots to SVG preserving the dark color theme, hence the weird light axes...

While working at the LSC rack, I lost the input pointing into the IFO (the TT wiring situation is apparently very fragile, and this observation supports the hypothesis that the drifting TTs are symptomatic of some electronics issue). After careful beam walking, it was recovered and the dither alignment system was used to maximize TRX/TRY once again. No lasting damage done. If I can figure out what the pin-mapping is for the TT coils in vacuum, I'm inclined to try installing the two HAM-A coil drivers to control the TTs. Does anyone know where I can find said pin-out? The wiki page links seem broken and there isn't a schematic available there...

Ok it should be possible to back it out from the BOSEM pin out, and the mapping of the in-vacuum quadrupus cable, though careful accounting of mirroring will have to be done... The HAM-A coil driver actually already has a 15 pin output like the iLIGO coil drivers that are currently in use, but the pin mapping is different so we can't just replace the unit. On the bright side, this will clear up 6U of rack space in 1Y2. In fact, we can also consider hooking up the shadow sensor part of the BOSEMs if we plan to install 2 HAM-A coil drivers + 1 Dual satellite amplifier combo (I'm not sure if this number of spares is available in what we ordered from Todd).

Some pictures of "magnet inspection" from Picasa.

The coating of some magnets are chipped...

Were these magnets chipped before the Ni plating?

RA: Yes, it looks like this is the case. We also smashed some of the magnets against a metal surface and saw that a black grime was left. We should hold the magnets with a clean teflon clamp to measure the Gauss. Then we have to wipe the magnets before installing. I share Jenne's concern about the press-fit damaging the plating and so we need to consider using using glue or the ole magnetic attachment method. We should not rely on the structural integrity of the magnets at all.

I made the inspection of the new custom DSub cables (came from Texas).

The shelled version gives us some chance to inspect/modify the internal connections. (good)
The wires are well insulated. The conductors are wrapped with the foils and then everything is in the braid tube shield. The braid is soldered on one of the connectors. (Attachment  3/4 shows the soldering of the conductor by intentionally removing one of the insulations).

It wasn't clear that if the conductors are twisted or not (probably not).

[Johannes, Koji]

We went around the LSC, PSL, IOO, and SUS racks to check how many dual backplane interfaces will be required.

Euro card modules are connected to the backplane with two DIN 41612 connectors (as you know). The backplane connectors provide DC supplies and GND connections.
In addition, they are also used for the input and output connections with the fast and slow machines.

According to the past inspection by Johannes, most of the modules just use the upper DIN41612 connector (called P1). But there are some modules exhibited the possibility of the additional use of the other connector (P2).

Tuesday afternoon Johannes and I made the list of the modules with the possible dual use. And I took a time to check the modules with DCC, Jay's schematics, and the visual inspection of the actual modules.

LSC Rack

• Common mode servo (D040180 Rev B)
  • Schematic source D040180 Rev B D1500308
  • Assesment: Both P1 and P2 are to be connected to Acromag, but there are only a few channels on P2
  • P1: 1A-32A Digital In
  • P2: 1A-3A Analog Out (D32/33/34, SLOW MON and spare?)
          9A Digital Out for D35 (Limitter)
          10A-15A Spare
          16A Digital In (Latch Enable/Disable)
          25A, 25C  Differential Analog in (Differential offset input, indicated as "BIAS") 
• PD Interface (D990543 Rev B)
  • Schematic source D990543 RevB
  • Assesment: No connection necessary. We don't monitor/control anything of any LSC PDs from Acromag.

PSL Rack

• Generic DAQ Interface (D990155) - This is a DAC interface.
  • Schematic source: Jay's page D990155 Rev.B All the lines between P2 and P3 are connected.
  • Assesment: Only P2 is to be connected to Acromag.
  • P1 DAC mon -> not necessary
  • P2 A1-A16, Connected to DAC in P2-P3
• PMC Servo
  • Schematic source: LIGO DCC D980352
  • Assesment: Only P1 (1A-9A) is to be connected to Acromag. (Just one DSub is sufficient)
  • P1 1A-9A
• Crystal Ref (D980353)
  • Schematic source: LIGO DCC D980353
  • Assesment: Only P1 (1A-4A) is to be connected to Acromag. (Just one DSub is sufficient)
  • P1 1A-4A
• TTFSS REV A
  • Schematic source: PNot found
  • Assesment: Probably Only P1 is sufficient. We need to analyze the board to figure out the channel assignment.

IOO Rack

• PD Interface (D990543 Rev B)
  • Schematic source D990543 RevB
  • Assesment: Only P1 connection is sufficient.
• Generic DAQ Interface (D990155)
  • Assesment: Remove the module. We already have the same module in PSL Rack. This is redundant.
• Common mode servo (D040180 Rev B)
  • See above
• Pentek Generic Input Board D020432
  • Schematic source Jay's page D020432-A
  • Assesment: No connection. There is no signal on the backplane.

SUS Rack

• SUS Dewhitening
  • Schematic source: Jay's page D000316-A
  • Assesment: No connection.
  • We can omit Mon CHs.
  • Bypass/Inputs are already connected to the fast channels.

I think we don't need to keep Crystal Ref: we can change this into a regular Wenzel box with no outside control or monitoring.

REFL165 was installed on the AP table last night.

Meanwhile I found the DC power level at the REFL PDs were 0.8~1.2V if the PRM is aligned and the IFO is not locked.
This corresponds to 16~24mA (20~30mW). This is too big.

The HWP of the REFL path were adjusted so that we have 6~10mA (8~12mW) on each PDs.

[Kiwamu, Jenne, Koji, Suresh]

The following steps in this process were completed.

1)  Secured the current ETMX (Old ETMY) with the earth quake stops.

2) Removed the OSEMs and noted the Sl no. of each and its position

3) Placed four clamps to mark the location of the current ETMX tower (Old ETMY's position on the table)

4) Moved the ETMX (Old ETMY) tower to the clean table flow bench.  In the process the tower had to be tilted during removal because it was too tall to pass upright through the vacuum chamber port.  It was scary but nothing went wrong.

5) Koji calculated the location of the new ETMX and told us that it should be placed on the north end of the table.

6) Moved the OSEM cables, counter balancing weights and  the 'chopper' out of the way.  Had to move some of the clamps securing the cables.

7) Moved the ETMU07 tower from the clean room to the ETMX table

8) Positioned the OSEMs as they were placed in the earlier tower and adjusted their position to the middle of the range of their shadow sensors.  The four OSEMs on the face did not give us any trouble and were positioned as required.  But the side OSEM could not be put in place.  The magnet on the left side, which we are constrained to use since the tower is not designed to hold an OSEM on the right side, seems a little too low (by about a mm) and does not interrupt the light beam in the shadow sensor.  The possible causes are

   a) the optic is rotated.  To check this we need to take the tower back to the clean room and check the location of the optic with the traveling microscope.  If indeed it is rotated, this is easy to correct.

   b) the magnet is not located at the correct place on the optic.  This can also be checked on the clean room optical bench but the solution available immediately is to hold the OSEM askew to accommodate the magnet location.  If time permits the magnet position can be corrected.

We have postponed the testing of the ETMU07 tower to 1st of Nov Dec.

 As a part of installation of two(X-ARM and Y-ARM) frequency counters in the 40m, I have tested their performance when using them both on a single Raspberry Pi. The timing plots are attached. There are almost no timing issues in this configuration and it can be said that there is no harm using both of the FCs on the same platform.

We will be installing the FC box inside the lab and carry out few tests with RF mon beat note inputs.

So far:

* New demod box has been placed in the LSC rack.

* An extra set of +\- 24V has been prepared at the terminal block where all the Crates get their power on the LSC rack.  The grounds were all connected up, but the hot wires weren't.  So there were extra spots available, but none that were pre-wired with my voltages.

     * To do this I turned off all the power supplies in the short rack, since I decided to be a live chicken rather than a dead duck.  After hooking up the new terminal block slots, I turned on the power supplies.

 * Make a power cable to go from the terminal block to the box

Still to do:

 * Connect the spare 55MHz LO and the POP (or POX or POY) unused 11MHz LO to the back of the box

 * Move the PD inputs to the new demod box rather than the borrowed AS11 and POP55 boards

 * Plug the I & Q outs for each freq into some spare ADC channels - must first make sure we have 4 open channels.

 * See if it works.

I installed the Tripp Lite SMX1000RT2U and Tripp Lite Smart1000LCD at the bottom of the 1x8 electronics rack. These are plugged in to power, and are ready for testing. All other cables (serial, usb, etc.) have been left on the table next to the 1x8 rack.

Today I installed two flipper mirrors M3 and M4 (see attached photo) to create alternate route for MC reflection camera beam. Both these mirrors are Y1-1037-45S. In nominal operation where IMC is using the WFS, we will keep M3 upright and M4 flipped down. When using WFS for AS, M3 will be flipper down and M4 will be upright to save the camera from the high intensity MC reflection beam.

Note that everytime M3 is flipper and put back upright, the alignment into WFS would need to be tuned as the flipper apparatus does not come back to same alignment everytime. I centered the beams on the WFS heads today and zeroed RF offsets usingC1IOO_WFS_MASTER>!Actions>Correct WFS RF Offsets script. After this, the IMC WFS loops are working as expected atleast for last 15 minutes that I have monitored them. Hopefully, this will remain consistent.

Upcoming work:

• Change the steering mirror that steers the beam to black hole to be a flipper mirror too as AS beam strength (measured when MICH was locked to bright port) is 0.3 mW and IMC WFS heads combined power is 0.5 mW in nominal operation, so we can not afford to dump any AS beam light.
• Put flipper mirror M1 and fixed mirror M2 mentioned in 40m/17320 for steering AS beam to IMC WFS heads.

After discussions with Yuta, I figured that a better optical layout is possible which does not interfere with the existing IMC WFS path at all. So I reset the IMC WFS path today (and zeroed RF offsets again) and changed the MC reflection camera and MC reflection beam dump (black hole) position to create space for a flipper mirror that will pop up in the IMC WFS path and steer in the AS beam. New proposed path is shown in the photo in cyan. Red is MC reflection beam, yellow is IFO reflection beam and orange is teh AS beam that we will pick up using flipper mirror M1. Note that I found an intense 6.4 mW ghost beam coming out of the interferometer in between IFO refl and MC refl beams. This beam is shown in pink which I have dumped now. This beam was earlier not dumped. We will need to investigate more on the source of this beam and correct it in the next vent.

[Anchal, JC]

I installed POP_SM4 and POP_SM5 in the ITMX chamber in the nominal positions. This must have affected the ITMX Oplev because I could see that one of the ITMX oplev beam was going through POP_SM5. It needs to be changed in order to follow the original plan. However, since POP_SM5 is a 1064 line mirror, it is transparent to the opleve beam, so maybe we can just use the ITMX oplev in the current fashion.

Next steps:

• Get flashing back on the XARM.
• Try to get the correct phase angle in POX11 so that we can lock XARM with IR too.
• Inspect ITMX Oplev. The quadrant sum is low so maybe it needs adjustment in the in-ar table.
• Check if ITMX oplev path needs to be adjusted inside the chamber.

allegra had fresh Debian 10 installed on it already. I installed cds-workstation packages (with the help of Erik von Reis). I checked that command line caget, caput etc were working. I'll see if medm and other things are working next time we visit the lab.

I have installed kerberos on Rossa, so that I don't have to type my name and password every time I do an svn checkin, since I'm making some modifications and want to be sure that everything is checked in before and afterwards. 

I ran sudo apt-get install krb5-user.  I didn't put in a default_realm when it prompted me to during install, so I went into the /etc/krb5.conf file and changed the default_realm line to read default_realm = LIGO.ORG. 

Now we can use kinit, but we must (as usual) remember to kdestroy our credentials when we're done.

As a reminder, to use:

> kinit albert.einstein

Password for albert.einstein@LIGO.ORG: (type your pw here)

When you're finished, run

> kdestroy

The end.

WARNING: since the workstations are all shared user, if you forget to kdestroy the next user can commit under your user ID.  It might be good to set the timeout to be something much shorter than 24 hours, like maybe 1, or 2.

Good call.  I added a line ticket_lifetime = 3600, which should make it destroy the credentials after an hour.