Finally installed all of the cabling and interlock boxes for the ESD drive.  There is a short cable at the feed through that goes to a current limiting resistor box.  From that box a 5 conduct cable with SHV connectors goes to the ESD amplifier.   The ESD amplifier has +-430V dc and +-18v dc supplied to it.  The HV supply is interlocked to a Vacuum gauge on the chamber.  

One item of note for the installation is the SHV coax cable label 1 goes to ESD amp port 3 and Coax cable 3 goes to ESD amp port 1.  I have used sharpie to mark this.

If the vacuum gauge trips the HV supply or if we have a power outage the HV supplies need to be switched on by hand.  The +430 Volt supply was found in Sink mode.  I am not sure how it arrived in this state because you would have to program the unit to do this and when the unit was turned on this was not done.  WE WILL have to track this to see if it is a problem. 

Before connecting the unit to Vacuum I checked the output values.

With See Table on attached pdf


								

HEPI was locked(put on stops) a couple days ago but its sensors remain on.  At the same time, the ISI interface electronics were powered down to allow decabling the air side.
This morning the ISI was locked (with lockers) and then the 800lbs of dummy payload was removed to make room for Suspension installs.
Thanks to Apollo Scott, Mark & Bubba.

ITMX tripped, this might have been a result of Jim's measurement, but I am not sure. 

The gps time was 1082487591

A ZFL-500LNB+ Mini-Circuits amplifier was added to the output of the COMM PLL BBPD. It is mounted directly to the output connector of BBPD using a SMA barrel. This amplifier was measured to have 29dB-30dB of gain in the 80MHz frequency range. Currently, there is a power supply on top of the enclosure. Longer term, we want to splice this into the +/-15V supply running to the BBPD. All other amplifiers were removed from the path.

8:15-8:35

Mike, Terry, Pablo, Daniel, Steban, Vern, Justin, Richard, Bubba, Kiwamu, Jim, Hugh, Mark, Jason, Aaron, Mitchell, Mark B., Keita, Jeff K.

LVEA is Laser HAZARD

HAM4- Cleaning crew in action – Karen and Chris
Craning activity by APOLLO
HAM5 ISI:  Removing payload –Hugh/Apollo 
TCS tables work continues. David/Aidan
TCS racks work at end stations (Richard & crew)
3ifo BSC ISI assembly  work continues in Staging Building – Mitchell
Dust monitors work at end stations. Switching the dust monitor unit in diode room. Jeff B.

no restarts reported.

Jim and I pulled/pushed all of the blade springs and installed flexures on unit 2 yesterday. Parts needed for unit 3 were discovered to be short of needed quantities have been ordered.

Alexa, Sheila, Stefan

Our goal today was to get a good diff readout going. For this we
- Commissioned the IMTY and ETMY optical levers, See snapshot.
- Recommissioned the x-arm dither - turns out the phases were tuned up for a different suspension setting - we need configuration control on all the suspension settings. Also see the snaphot.
- With that we got fairly stable arm locking - at least for a while - see below.

- Next we tweaked up the DIFF beat note on ISCT1. We got -20dB signal out of the PD.
- Th PLL locked for short stretches, but essentially always runs out of range after a few seconds.

- Thus we decided to work on top-mass slow feed-back: There was a lot of confusion, but once everything was done right, it sort of worked.
- One thing we noticed along the way, is that our 1-3Hz BLRM traces pick up increases in noise with an roughly hourly periodicity. This noise somehow translates into extra length motion at 0.05Hz. 
- We also fine-tuned the ETMY top mass L2P filter - see Arnaud's log
- The slow feed-back gain was however limited by our main suspension resonance, which meant that we couldn't suppress the DIFF motion enough.
- We thus decided to work on the L2L filters, which should give us the ability to increase the UGF of that loop and get more suppression.
- We got a simple L2L measurement going, but more work is needed.

Something is wrong with ETMY stage 2 RX Tbetter....  we clearly have less opLev peak to peak when we turn this to Tcrappy. 

So the configuration we are using now is Tbetter everywhere except Tcrappy on RZ on stage 1 +stage2, and Tcrappy on stage 2 RX, sesnsor correction from the ground to stage 1 in X Y and Z. 

We also briefly tried T750 on stage 1 Z motivated by llo alog 12164, this wasn't good so we will have to do a more thoughfull job of importing those improvements.

Yesterday, the modified UIM coil drivers for ETMY and ETMX were tested in-situ. The transfer functions are showing an average drive increase of ~3.8 for ETMY and ~3.9 for ETMX comparing them before and after, which corresponds to the modification as described in T1400223.
A second test was carried out, using the monitor boards current channels. The test consisted in sending the equivalent of 1V to the coil drivers, to each of the UIM osem channels, and recording the current increase with channel ${QUAD}_L1_FASTIMON_${OSEM}. Jeff K helped me for the calibration of those channels.

The output voltage of the "fast current channel" of the monitor board as described in T1100378 is measured across the resistor Zout. The relation between the current and the ouput voltage is described in the last equation of Jeff's notes attached, with R1/R2 = 1/3 and Zout = 2010 ohms. In other words Current_readback_calibrated (A) = FASTIMON_Readback (cts)* 1/1638.4 (V/cts) * 3/2 * 1/2010 (ohms-1)

For ETMX I measured a transconductance of ~0.6 mA/V for each channel which matches pretty well with the design, but for ETMY it didn't quite match. First, only two channels (even though the mass was moving) were seeing a response, and secondly, the working channels were showing ~3mA increase for 1V drive. Since the transfer function shows that the driver is working as expected we certainly have something going on with the monitor board.

The non functioning channels are LL and UR osems. For UL and LR, when no voltage is sent to the coil driver, the readback sees ~4000 cts (as shown on the screenshot).
 

Days Activities

• Several ISIs were tripped this morning...perhaps due to EQ last night?
• HAM5 cleaning in morning
• Transition LVEA to Laser Safe?
• MY baking of RGA equip late morning
• EX ESD high voltage work this morning (maybe EY later)
• Praxair fill for CP6 at MX (9am?)---Sending CP6 to MAJOR alarm level
• Transition EX to Laser SAFE--probably HAZARD later
• LVEA transitioning to SAFE in the morning
• Septum removal, sealing septum gap, tapping hole in septum, & laying septum down
• Checking clean status at HAM5 (Jeff & Margot)
• Pressure Sensor at MY still is reading HIGH (MAJOR Alarm), but this is because Kyle is doing work on it (it'll be like this on the order of a month)
• LVEA transitioning to laser HAZARD at 3:45-ish
• Matt H, Aiden, and David H. heading out to work on TCS

Went through the Operator check of saturations with HEPI this afternoon.  The HEPI Saturation Counters which I had to reset were: 

HAM2, HAM4, ITMx(BSC3), ITMy(BSC1), ETMx(BSC9), ETMy(BSC10)

A pressure sensor at MY had been MAJOR Alarming the last few days, but this is due to it being worked on.  It will be displaying values of a higher pressure for a month or so while it is valved out and being worked on.  To prevent getting alarms from this, we've bumped up the MAJOR alarm setting to 1x10^-6 (originally it would alarm at 5.11x10-8).

Since the Vacuum computer was really slow, Dave ssh-ed into the computer (still was slow) & did the following:

vacuum@control0:~$ caget HVE-MY:Y5_246BTORR.HIHI
HVE-MY:Y5_246BTORR.HIHI        5.11e-08
vacuum@control0:~$ caput HVE-MY:Y5_246BTORR.HIHI 1.00e-06
Old : HVE-MY:Y5_246BTORR.HIHI        5.11e-08
New : HVE-MY:Y5_246BTORR.HIHI        1e-06

We must revert the alarm setting when the VAC work is complete.

Baking will continue for as long as a few weeks

HEPI safe.snap files had the wrong ..._L4C_THRESH_MAX values recorded, as pointed out by Dave yesterday. Those safe.snap files are now fixed. The new versions are committed under the SVN -r7796.

Details are attached.

The Apollo crew was unable to get wrenches to the large clamp bolts which retract the bellows of the chamber's west side 60" flange.  We needed to remove the Feedtrhu protection shroud and the cabling attached to the feedthru.  So the WHAM6 isi interface electronics were powered down.

Mark B. and Gerardo

Yesterday (4/22/14) Gerardo and I measured the vertical mode Q of the OFIS for three different positions of the ECD block to try to get the Q in the specified range of 25-30.

The OFIS was set up on the optical bench in the H2 laser enclosure. The ECD block sits on a tray below the payload which is supported by four groups of vertically pointing screws at accessible positions around the edge of the structure. Gerardo had earlier attempted to set the ECD block at the nominal height using the spacer tool provided but found that this was too high and caused interference. He therefore lowered the block until it was just barely clear plus approximately an extra two turns of the 1/4-20 screws. This was our starting point for further adjustments.

To measure the vertical Q, we used the laser pointer and QPD from the monolithic violin mode setup and used a convenient screw on the top of the payload to partially block the beam. We displayed the "pitch" output of the QPD box on a digital oscilloscope with a 1 sec/div timebase and photographed the screen to capture the data. I read off the peak positions with GraphClick, and worked out the logarithmic decrement and Q with Mathematica.

For the initial position, the Q was 10.7. We lowered the ECD by one turn on all the screws and got Q = 18.9. We lowered the ECD another half turn and got Q = 23.3. Finally, today (4/23/14) we lowered the ECD another 3/4 turn and got 27.8, which is in spec.

Attached is a JPG of the setup, a PDF of all the screenshots, and for the fourth and final run, the Mathematica notebook, PDF thereof and the raw data.