Attached are plots of dust counts requested from 5 PM April 9 to 5 PM April 10.

Odd drop off in counts in the beer garden (LVEA 5) at around 1 AM.

Figure 1 shows beam spot views associated with the BS. I use these to look for potential scattering problems; the camera and flash is placed very close to the center of the optic where the beam spot will be. The flash mimics the scattering of interferometer light from the beam spot and lights up regions that will retroreflect interferometer light back to the beam spot, where it can recombine with the main beam to produce scattering noise. Of course the technique is limited by different angular distributions of scattered IFO light and light from the flash, as well as by color differences, but it gives a rough idea. I worry a bit about how bright the ITMY cage is, as viewed from the BS beam spot. 

Kyle and I left a GNB bellows inside one of the small cleanrooms in the LVEA, located by the North wall of the East bay.
Please do not remove from under cleanroom, if this item is on the way please let us know.

I updated the h1cds alarm handler files to include the front ends which have been added recently. The alh config files alarm on CPU MAX for IOP and user models, and STATE_WORD for the IOP model. Not all iop safe.snaps have been completed to set the STATE_WORD alarms.

I also updated the h1alarmmanager.db EPICS database for the alarm manager system, and its associated MEDM screen (see attached image).

GregG, JimW

After IAS gave a thumbs up on the BSC2 alignment, Greg and I started attaching the vertical HEPI actuators. With relatively few hiccups, all four actuators were attached. Shifts were relatively small at the dial indicators (all less than .003"), but we'll confer with IAS to make sure we haven't screwed up too bad. Horizontal actuators  are up next, should be able to finish by this time tomorrow.

08:00
Dust monitor alarm in EY and EX.  
Crane cleaning in EY and Apollo working in EX
LASER Hazard

09:08 Transition to Laser Safe – Michael R
09:40 DOE start seismic testing in 300 Area near station H3A
Dave B updating alarm handler
Betsy, Travis, Margo, Kate, and Hugo working in and around HAM 3, HAM2, and BSC2
13:08 DOE stop seismic testing
Michael R working with Apollo cleaning in the PSL Enclosure 
Sheila & Keita move ISCT1 into HAM 2 cleanroom and setup laser safety barriers
Filiberto C & Erin pulling in rack cables for BSC3
Filiberto C & Ben A pulling in rack cables at EX for BSC9    

Kiwamu, Michael R

We increased the power going into the ref cav to get more light into the ALS fiber pick off. We now have about 23 mW going in. We ran a transfer function and found a lot of noise around 380 kHz, very close to the UGF. To get rid of this we decreased the common gain to 2 dB, giving a gain margin of 2dB. The UGF is now at 200 kHz.

Additionally, the PD in transmission of the ref cav was saturating, so I put an ND 0.3 filter infront of it. This was the lowest one I could find, and it is now reading ~ 3V.

Kate G, Margot P, Travis S, Betsy W

MC2 has had its blade tip EQ stops replaced with the new shorter version.  HAM2 and 3 have been fully photographed for contamination control efforts.  Spray cones for both the HSTS and HLTS were assembled after some minor modifications were made on the fly.  MC2 has had its first spray on First Contact layers applied.  This required moving the baffle in front of the suspension in order to get the spray cone in place and to make room for a hand and spray bottle.  Its position was marked with extra dog clamps and will be returned upon completion of cleaning.  This work will continue tomorrow with First Contact being sprayed onto the remaining MC and PR suspensions in both chambers.  Additionally, the BS has had its IAS thin-coated First Contact reinforced for its upcoming removal necessitated by baffle alignment. 

HAM3-ISI was rebalanced this morning. CPS readouts are attached.

SUS still have teflon shims to remove (white, on attached picture). Those are set between the earthquake stops and the optics, as a protection for the glass. We tried to account for them while balancing. CPS readouts are given with those shims on.

Kiwamu, Sheila

This morning Kiwamu and I went into the PSL to see if we could improve the coupling of the reference cavity transmission into the ALS fiber.  There were 4.72mW of light incident on the fiber coupler. We connected the two ends of the fiber at the field rack to each other so that the light was returning to the PSL with some extra losses due to the extra coupler, and saw 1.46mW coming out of the fiber.  We moved the lens closer to the fiber coupler closer to the fiber coupler by about 1 cm total, and saw the power on our power meter inside the PSL increase to 2.1 mW. We noticed that as we moved the lens the alignment changes not only in yaw but also in pitch, meaning that the beam is not centered vertically on the lens.  We can probably improve the coupling more by adjusting the lens positions more, but this will be easier to do if we have a beam leveler and make sure the beam is really level before we start.  

When we left Kiwamu measured the power coming out of the fiber at the rack, which was 2.4mW, so now the coupling efficiency is 51%.  Better than 37% measured yesterday but there is still room to improve.   

Travis and I checked the orientations of the 8 UIM permanent magnets, in-situ inside BSC1, and found them to be correct.

[Cheryl, Giacomo, Greg]

Using only IM1 and IM2 (under the assumption that the alignment done before the power outage was still good), we realigned the beam coming out of the (flashing) IMC to the fiducials we had downstream of IM2.

We initially used just the input and output aperture of the FI, obtaining these offsets

IM1 Pitch: 3000

IM1 Yaw: -1000

IM2 Pitch: -1410

IM2 Yaw: -1300

Then, we refined the alingment using IM1 to center on the iris past PRM, and IM2 to center on the iris in front of PR2. These were the offsets at the end of the process:

IM1 Pitch 2730

IM1 Yaw -170

IM2 Pitch -1380

IM2 Yaw -300

With this alignment:

- the parking beam reached the hole n the parking baffle with the same offset values for PRM (pitch = 2500, yaw = 50).

- the refl beam goes all the way back and easily clears the last baffle before entering HAM1

-the input aperture on the FI magnet is centered

- the centering into the AOE2 baffle is good (i.e. slighly off-centered, as neeed)

We are thus confident that we have realigned the beam out of the IMC to the beam we used before the power outage, and so all the resst of the alignment should be reasonably good.

Note that the beam appears to be slightly off-center (between 0.5~1 beam radii) on the output aperture of the FI, but we have no memory of how well that was centered before the power outage.

We then checked that the beam coming back from PR2 is reasonable centered on PR3. because the beam was scarcely visible and bigger than our target, we just scanned PR2 pitch and yaw to find the limit of visibility of the beam on the target, and then took the average. Our best estimate for PR2 the send the beam back to PR3 are:

PRM pitch = 1400

PRM yaw = 900

We then:

- re-centered the IMC REFL in the periscopes

- placed reference dog-clamps ad remove all the irises

- adjust a few baffles on IM2

- remove all loose/temporary IO hardware from HAM2.

We also went to remove the black glass from AROM RH6 in HAM3 (planning to either quikly find a way of cutting it, or just leave it out) to discover that the black glass had never been installed in the first place.

Attached are plots of dust counts requested from 5 PM April 8 to 5 PM April 9.

There seems to be a large spike in > .3 micron counts at end Y from ~ 2 AM - 3 AM, and a smaller corresponding spike at end X.

I measured the beam power at various points around the reference cavity (refcav) on the PSL table.
This is a part of the effort to increase the power of the beam that are distributed to the end stations through the fibers for ALS.

Apparently there is one point where we can easily squeeze more beam power out --- the half wave plate and PBS in refcav's AOM path. The PBS throws almost half of its incident power away at the moment (see the numbers below). So rotating the half wave plate will easily give us a factor of two increment in the entire fibers.

* * * * *  Measured Values in the AOM path * * * * *
Before the PBS in the AOM path = 36.0 mW
Transmitted light of the PBS in the AOM path = 18.69 mW
Reflected light of the PBS in the AOM path (blocked by a dump) = 15.20 mW

* * * * *  Measured Values at some other points * * * * *
Incident on refCav = 11.40 mW
Transmitted light of the refcav after the ALS Faraday = 5.69 mW
 

Keita, Kiwamu, Sheila

This afternoon we aligned the beam for the ALS doubling path from the PSL through HAM1 and out to the viewport for ISCT1.  

When we began Kiwamu saw that the beam was entering the light pipe nearly at the bottom of the aperture on the PSL side, although it was too high inside the chamber.  The top mirror of the periscope is mounted so that it can only move vertically, so Kiwamu moved it up slightly.  After that the beam that we saw in the chamber was probably a reflection off of the sides of the light pipe, but Kiwamu was able to recover by steering to get a reasonable beam.  After walking the beam in this way, we arrived at an alignment where the top periscope mirror is at the highest position possible.  On the PSL side the beam enters the light pipe slightly low (~7mm) and to the west (~5mm) in the ~75 mm aperture.   At the viewport in HAM1 the beam arrives slightly to the east of the center of the viewport (less than 10% off center) and the height is adjusted so that the beam hits the steering mirror at its center.  we then adjusted the position of the steering mirror (moving it less than an inch to the east) so that the beam is centered on it in yaw, and centered on the viewport heading towards ISCT1.  

We also considered looking at the alignment of the IFO reflected beam using mode cleaner flashes, but Cheryl told us that that beam will be moved later anyway when IM1+2 are moved, so we held off.  The high power beam dump we did not install because it is not ready yet, a part is missing.  

IAS (DCook, JOberling) setup for pitch & yaw alignment on the BS optic. IAS directed SEI to perform a CCW yaw of 400urad. JWarner did a 1/3+ turn of all HEPI Springs to go CCW. IAS then reported ~45urad CCW remained. SUS TSadecki continued to do Pitch adjustments and the Yaw number may change slightly. This CCW Yaw calculates to move the BS ~0.1mm -Y. Based on the alignment results of 28 March the BS was already 0.8mm -Y and it looks like we pulled it East (-Y) close to 0.1mm based on the Dial Indicators.  So, Jim did a very careful +Y translation (west) of ~1mm with the HEPI Springs.  Jim did two rounds of 1/4turn west of all Springs.Based on the Dial Indicators, this is what we ended up doing.

From the last time we did an Optical Table elevation/level check we have shifted up 0.1mm with only 0.03mm tilt over the span of the Optical Table.

From the X Y Z alignment (28 March) we shifted west 38mils & north 4mils.  The rotation imparted by the translation since Yawing the table this morning is 0.0urads.  Yes 0.0; the DIs all read the same translations implying no rotation measured--Good work Jim!

While investigating lost frames, Tx/Rx errors and a non zero CRC for the Corner MSR L8_9 Vertex (EK1521) (the terminal for the fiber connection to the H1 electronics room), the h1ecatc1 computer froze and restarted. I had looked into the chassis housing this terminal in the MSR and had not seen anything obviously wrong with it. However, the error LEDs on the Corner MSR L2 (EL3202-0010) (the temperature probe readout) terminal were both lit. After the computer restarted I restarted the system manager and deleted the configured terminal for the connection to end X (it was disabled because it is not connected), and checked that scanning the modules gave an identical configuration. It did, and I put it in run mode and started PLC1 and PLC2. The previous errors with the EK1521 are gone, but the error LEDs are still red on the EL3202. I have not restarted the EPICS IOCs.