[EricG, manasa]

The He-Ne laser oplev setup was swapped with a fiber-coupled diode laser from W Bridge. The laser module and its power supply are sitting on a bench in the east side of the SP table. 

 [Manasa, Diego]

This is our first time touching tables for Frequency Offset Locking. 

The goal was to couple the 1064nm that leaks after the SHG crystal and couple it into the fiber before we run it along the length of the arm. 

The fiber has been mounted at the end but there is no light coupled into the fiber as yet.

In the process, the following were done:

1. ETMY oplev servo disabled. This was enabled after the work.
2. NPRO laser power was reduced so that nothing gets burnt accidently while putting things on the table. This was also reset after the work.

The arms could be locked to green and IR after the work. So I am hoping today's work will not affect locking.

The Y end aux laser light leaking after the doubling crystal has been coupled into the 70m long PM fiber. 

Input power = 250mW;  Output after 70m = 20mW

The poor efficiency is partially due to the ellipticity of the beam itself and partially due to the compromise I had to make using a single lens to couple the light into the fiber (given the limitations in space). But 20mW should be more than sufficient for a beat note setup.

Light propagates as follows after the doubling crystal:

Doubler ---> Harmonic Separator (45deg) ---> Lens (f=12.5cm) --> Steering mirror (Y1) --> Fiber collimator ( Thor labs CFC-2X-C) --> FIber end

I will update photos of the setup shortly.

I have left the 70m fiber in its spool sitting at the Y end and blocked the light before the last Y1 steering mirror in the above setup. So it should be safe.

Other:

Through the course of the work, I disabled the ETMY oplev and enabled it before closing the enclosure. I also reduced the AUX laser power and brought it back up after the work.
I did a check to see if the arms are locking in both IR and green and they did.
 

Since I obtained a poor coupling efficiency from the earlier setup, I went back to calculate the coupling efficiency of the current setup.

For the current setup, I took the average of the x and y waist of the input beam and calculated the distance at which the input beam diameter would match the (fiber +collimator) beam diameter.

Average waist = 40.2um @-3.3mm from face of doubling crystal

(Fiber PM980 + Collimator f=2.0mm) beam waist = 205um

Distance(z) at which the input beam waist is 205um = 11.9cm

The closest available lens was f = 12.5cm. So I used it to couple the input beam by placing it at z ~12.5cm on a micrometer stage.

Since this gave only 10% coupling, I went back to calculate (using 'a la mode') the best possible coupling that can be obtained taking into consideration the ellipticity of the beam.

The maximum obtainable coupling (mode overlap) is 14.5%  which is still poor.

Redesign

Taking into account the ellipticity of the input beam, the available lenses and the space restrictions (lens can be placed only between z= 8 to 28cm), I calculated the best possible coupling efficiency (using 'a la mode').

The maximum possible mode overlap that can be obtained is 58.6% (matlab code and plot attached)

>>auxmode

modematching = 0.58632 

Optimized Path Component List:

    label    z (m)     type    parameters         

    -----    -----     ----    ----------         

    L1       0.0923    lens    focalLength: 0.0750

I looked at what are the situations that make ETMX lose alignment.

This is not occur all that often this morning; less than 10 times in may be the last 4 hours of poking the X arm. I found that the bad behavior of ETMX also exists in certain other cases apart from the case when we enable LSC.

(I) Even the MISALIGN and RESTORE scripts for the suspensions make the suspension behave bad. The RESTORE script while in the process of  bringing back the suspension to the place where it was, kicks it to some place else sometimes (even with LSC disabled)

(II) The suspension also gets kicked while realigning ETMX manually using sliders at 10^-3 (pace of 2-3 steps at a time).

I am suspecting something wrong right at the coil inputs and gains of the suspension.

Also, I recollect that  we haven't done a check on the X arm LSC limiters and filters ramping times like it was done for the Y arm ( Elog 9877 ). We should do this check to be sure that we are not seeing a mixed puddle of problems from 2 sources.

I used the above configuration and was able to obtain ~52% coupling.

Input power = 250mW
Output power with absorptive ND 1.0 = 13 mW

I used the absorptive ND filter before the lens to keep the coupled output power within the range of fiber power meter and also avoid scattering of enormous amount of uncoupled light all over the table.

I have attached the screenshot of the out of loop ALS noise before opening the table (BLUE) and after closing down (MAGENTA). The beat note frequency and amplitude before and after were (14.4MHz/-9.3dBm) and (20.9MHz/-10 dBm).

I ran 3 BNC cables from the SP table to 1X7 rack so that we can have 16 bit channels for the Ontrak PD that will be used to test oplev lasers. The BNC cables are plugged to the Ch 29, 30 & 31 that were already created for this purpose (elog 10488)

The PSL HEPA stopped working while it was running at 80%. I have closed the PSL enclosure.

Steve is working to fix this.

Summary: Cannot find beatnotes between the arms and PSL.

I wanted to measure the ALS out of loop noise before putting stuff on the PSL table for frequency offset locking.

But I was not able to find the beat notes between the arms and PSL green. All I could find while scanning through the end laser temperatures is the beatnote between the X and Y green.

EricQ says that he spent some time yesterday and could not find the beatnotes as well.

Debugging and still could not find:

1. Checked the FSS slow actuator. This was close to zero ~0.003

2. Checked the green alignment on the PSL table. Everything seems fine.

3. Checked the actual PSL laser temperature. It was 31.28deg and not very far from when it was last set at 31.33deg elog.

4. Also checked the end laser temperatures. Both the lasers are ~40deg (where I could see the beatnote between the arms). Based on the plot here and  here , we are very much in the regime where there should be a beatnote between the PSL and the arms.

[Steve, Diego, Manasa]

Since the beatnotes have disappeared, I am taking this as a chance to put the FOL setup together hoping it might help us find them.

Two 70m long fibers now run along the length of the Y arm and reach the PSL table.

The fibers are running through armaflex insulating tubes on the cable racks. The excess length ~6m sits in its spool on the top of the PSL table enclosure.

Both the fibers were tested OK using the fiber fault locator. We had to remove the coupled end of the fiber from the mount and put it back in the process. So there is only 8mW of end laser power at the PSL table after this activity as opposed to ~13mW.  This will be recovered with some alignment tweaking.

After the activity I found that the ETMY wouldn't damp. I traced the problem to the ETMY SUS model not running in c1iscey. Restarting the models in c1iscey solved the problem.

Found the IR beatnote between PSL and Y end laser.

Since our goal was to find the beatnote ASAP to recover ALS, I ignored the fine details in alignment. I will revisit the setup to make some improvements in the near future.

1. Coupled the PSL IR beam leaking after the doubler into the fiber. We have only 10% coupling into the fiber at the PSL table right now (6mw); but this will be improved once I get a suitable translation stage for the telescope.

2. PSL IR --> PM980 fiber --->50-50 fiber beam splitter ---> 50-50 fiber beam combiner
  AUX Y ---> PM980 fiber ---> 50-50 fiber beam combiner
The output port of the fiber beam combiner is connected to the fiber coupled broadband RF PD.

3. The RF output of the PD when connected to a spectrum analyzer shows a beatnote of -50dBm. The small amplitude of the beatnote is due to the laser power being attenuated before coupling into the fiber to keep the PD safe.

Attached is photo of how the setup is put on the PSL table. We will put all the stuff in a box once the X setup is also in place.

 I looked at the endtable for possible space to setup optics in order to couple the X end laser into a PM fiber.

Attached is the layout of where the setup will go and what are the existing stuff that will be moved.

Still not able to resolve the issue.

Except for c1lsc, the models are not running on any of the FE machines . I can ssh into all the machines but could not restart the models on the FE using the usual rtcds restart <modelname>

Something happened around 4AM (inferring from the Striptool on the wall) and the models have not been running since then.

[Steve, Manasa] 

Two 70m long fibers are now running through armaflex insulating tubes along the X arm on the cable racks. The excess length of the fiber sits in its spool on top of the PSL enclosure. 

Fibers were checked after this with the fiber fault locator (red laser) and found OK.

Attached is the timeline for Frequency Offset Locking related activities. All activities will be done mostly in morning and early afternoon hours.

[Diego, Manasa]

We looked into the configuration and settings that the frequency counters (FC) and Domenica (the R pi to which the FCs talk to) were left at . After poking around for a few hours, we were able to readout the FC output and see it on StripTool as well.

We have made a list of modifications that should be done on Domenica and to the readout scripts to make the FC module automated and user-friendly.

I will prepare a user manual that will go on the wiki once these changes are made.

Elaborate to do list:

1. The FC module should be mounted on the IOO rack. Domenica has to be powered up appropriately to the rack power supply.

2. The fiber chassis needs to be built. This will hold all the fiber components and will sit inside the PSL enclosure.
Fiber connectors and fiber couplers need to be installed in the chassis. Attached is the cartoon sketch of layout in the chassis.

3. User guide for FC module (work in progress)

1. FC module has been mounted on the IOO rack. The module gets it AC supply from the powerstrip already installed on the back side of the rack.

2. The fiber chassis has not been put together completely. We have still not received the front and back panels for the chassis; which is keeping me on hold. Diego is almost done with his housekeeping on Domenica. He will post an elog with all the details.

3. User guide for FC module (work in progress)

I was working around the PSL table today.

I wanted to modify the telescope that couples PSL light into the fiber; now that I have the translation stages for the lenses. I could not finish it as the locking work started earlier than usual this afternoon. I measured the out of loop noise for ALS error signals before I opened the PSL enclosure. X and Y beat notes were at -18dBm at 49.3MHz and -29.56dBm at 62.2MHz for this measurement. DTT data can be found in /users/manasa/data/141210/ALSoutLoop.xml; so there is reference to go back to in case of any damage done due to the work on the PSL table.

Also, I received the front and back panels for the Fiber chassis and put it together. Find photos (front panel and inside) of chassis in attachment. This will go inside the PSL enclosure tomorrow.

I am not sure if people have been noticing it lately; but the slow actuator on the PSL FSS has been railing up quite often these days. I found it at >0.8 and as high as 1.5 on certain occasions before resetting it to nominal zero.

It could be because the PMC alignment needs to be tweaked. The night crew should consider doing this before starting to lock.

Status of IFO:

1. The X end slow computer is down. ETMX sliders and buttons on the ETMX suspension screens have gone white. I have disabled the ETMX oplev because it is largely misaligned in yaw. I am not poking it and leaving it as is for the time being.

2. The Y arm green alignment had drifted and GTRY was down to 0.15 . I tweaked the alignment using the last two steering mirrors and brought GTRY to 0.7 which gives a beat note of -14dBm.

 I assembled the telescope to couple PSL light into the fiber. The maximum coupling that I could obtain was 10mW out of 65mW (~15%).

I was expecting to achieve 80-90% coupling from my design estimates. It makes me wonder if the beam waist measurements made by Harry during summer were correct in the first place. I would like to go back and check the beam waist at the PSL table.

Also, we need a pair of 8m (~25 feet) long SMA cables to carry the RF signal from the beat PD on the PSL table to frequency counter module on the IOO rack.

Steve says that we had a spool of SMA cable and it was borrowed by someone a few months ago. Any updates on either who is holding it or if it has been used up already would help.

The X end slow computer was down this morning. So I used only the Y arm ALS to record the noise level for reference. DTT data for ALSY out of loop noise before opening PSL enclosure is saved in /users/manasa/data/141211/ALSYoutLoop.xml

 I missed to elog this earlier. I have temporarily removed the DC photodiode for GTRY to install the fiber holder on the PSL table. So GTRY will not be seeing anything right now.

Unfortunately the order placed for beam samplers last week did not go through. These will be used at the X and Y end tables to dump the unwanted light appropriately. Since they will not be here until Tuesday, I revised the timeline for FOL related activities accordingly.

I was working on the PSL table today. 

Since the rejected 1064nm light after the SHG crystal is not easily reachable to measure beam widths close to the waist, I put a lens f=300mm and measured the beam size around its focus. I used this data and redesigned the telescope using 'a la mode'.

I used a beam splitter to attenuate the beam directed towards the fiber. The reflected beam from BS has been dumped (I need to find a better beam dump than what is being used right now. 

I have only ~200uW at the input of the fiber coupler after the BS and 86uW at the output of the fiber (43% coupling). 

I moved the GTRY DC photodiode and the lens in front of it to make space for the fiber coupler mount.

The layout on the PSL table right now is as shown below.

I have also put the fiber chassis inside the PSL enclosure on the rack. I moved the coherent spectrum analyser controller that is not being used to make space on the rack.

I was working around the PSL table and Y endtable today.

I modified the Y arm optical layout that couples the 1064nm light leaking from the SHG crystal into the fiber for frequency offset locking.

The ND filter that was used to attenuate the power coupled into the fiber has been replaced with a beam sampler (Thor labs BSF-10C). The reflected power after this optic is ~1.3mW and the trasmitted power has been dumped to a razor blade beam dump (~210mW).

Since we have a spare fiber running from the Y end  to the PSL table, I installed an FC/APC fiber connector on the PSL table to connect them and monitored the output power at the Y end itself. After setting up, I have ~620uW of Y arm light on the PSL table (~48% coupling).

During the course of the alignment, I lowered the power of the Y end NPRO and disengaged the ETMY oplev. These were reset after I closed the end table.

Attached is the out of loop noise measurement of the Y arm ALS error signal before (ref plots) and after.

Since we will not be doing any major locking, I am taking this chance to move things on the X end table and install the fiber coupler.

The first steering mirror shown in the earlier elog will be a Y1 (HR mirror) and the second one will be a beam sampler (similar to the one installed at the Y endtable for the fiber setup). 

Configuration:

Doubler --> Y1 ---> Lens (f=12.5cm) ---> Beam sampler --->Fiber coupler

The fiber coupler mount will be installed in the green region to the right of the TRX camera. 

This work will involve moving around the TRX camera and the optic that brings the trans image on it.

Let me know if this work should not be done tomorrow morning for any reason.

I was working around the X endtable and PSL table today.

1. Y1 mirror, beam sampler and the fiber coupler have been installed.

2. Removed TRX camera temporarily. The camera will be put back on the table once we have the filter for 532nm that can go with it.

3. Removed an old fiber mount that was not being used from the table. 

4. Lowered the current for X end NPRO while working and put it back up at 2A before closing.

5. The fibers running from the X end to the PSL table are connected at an FC/APC connector on the PSL table. 

6. Found the HEPA left on high (probably from yesterday's work around the PSL table). I have brought it back down and left it that way.

I have not installed the coupling lens as yet owing to the space restrictions - not enough space for footprint of the lens. I have to revisit the telescope design again.

I was working around the PSL table this morning.

1. I have fibers running from the Y end and the PSL table to the Optical Fiber Module for Frequency Offset Locking. 

Y+PSL out power is ~200uW. From the transimpedance and responsivity specs of the RFPD (ThorLabs FPD310), we expect ~100uW or -10dBm RF power. I have not hooked up the RF output to a spectrum analyser to confirm this as yet.

2. Also, Steve and I ran RF cables (LMR-195A) from the PSL table to the FC module on the IOO rack.

I have attached a photo of the ETMX table. The path of the 1064nm light rejected after the doubler and the green light are indicated for reference.

The fiber mount can only be mounted in the green space shown in the picture.

Calculating lens solutions for coupling the 1064nm light rejected after the doubler into the fiber, a lens of f=12.5cm should be placed at z=15.31cm (measured from the waist in the doubler crystal) gives the best ~80% coupling. This falls in the blue region where there is not enough space to mount a lens. 

The region marked in orange has enough room for a lens; but the lens solutions give a coupling <10% which means there will be light scattering everywhere.

I am open to any suggestions on how to go about this.

I worked around the PSL table today.

The Y+PSL output from the optical fiber module for FOL was fed to the input of the Thorlabs FPD310. 
200uW of incident light on the RFPD gave an RF signal of -70dBm as measured on a spectrum analyzer.

I swapped the beam splitter along the PSL path so that the incident power on the RFPD is ~1.5mW (Maximum incident power that the PD can tolerate is ~2mW).
This RF signal generated was - 43dBm which is still small for the input to the frequency counter module.

I checked this with a function generator and found that the frequency counter requires around -25 to -30 dBm at the input.

I plan to use the Minicircuits ZFL-1000ln that is on the IOO rack but not being used (This was used for green beatnote amplification but is not required/used anymore) to amplify the RF signal to the frequency counter.
If anyone has any objections to using this amplifier for the frequency counter, let me know.

Before starting to move things around the PSL table, I measured the ALS out of loop noise for reference. The noise spectrum showed excess noise around 30Hz.  The traces in blue were taken before I went in and those in red were taken after my work.

I also looked at the power spectrum of LSC-TRY_OUT to see if the noise is from the IR lock itself and there was nothing suspicious with it. 

Since the green transmission was 50% lower than the usual, I touched the steering mirrors for green at the Y end table to get a better transmission and beat signal. The noise still hasn't disappeared. 

I am not sure if this could be from our neigbors who have been running rock experiments since morning. We should check back to see if this noise disappears once they shut down.

DTT xml files are available in directory /users/manasa/data/150109/

The above mentioned amplifier has been used to amplify the input to the frequency counter. The frequency counter is now getting an input that it can read.

I have done an edit to the ALS medm screen and the PSL and AUX Y laser beat frequency is now readable.

As Jenne pointed out, this is still not fully tuned. 

For example, I found today that the frequency counter requires more power at the input >= -20dBm to measure frequency inputs < 40 MHz. Since the RFPD gives ~ -40dBm at its output, the ~20dB gain amplifier will not be enough to measure low frequencies in case the beat power at the PD drops (which is very much possible when the alignment drifts or things move around on the PSL table).  So I am shopping for an RF amplifier with higher gain to replace the current one. In the meantime, I will test the PID loop for set point frequency > 40MHz.

I have also observed the frequency difference between the measured frequencies on FC and the spectrum analyzer. I am not sure where this comes from as yet. 

At this point, the FC readout is only reliable enough to find a beatnote that is lost on the spectrum analyzer.

I was around the PSL table and the X end table today.

X end table:

I was at the X end table making some distance measurements for the telescope to the fiber coupler. I have NOT moved anything as yet.

PSL table:

I wanted to get some data to look at the beat note frequency discrepancy between the green and IR. 

I tried making measurements using the spectrum analyzer at the PSL table but the MC was getting unlocked quite often with PSL enclosure open and HEPA on high. 

So I switched off the power supplies to the RFPDs (3 of them) on the PSL table and disconnected the Xmon input to the adder (at the IOO rack) which brings the green beat note signals to the conrol room. I connected the fiber RFPD output to the adder and took a bunch of measurements of the green and IR beat notes from the spectrum analyzer in the control room. I have NOT undone this setup assuming there are no locking plans for tonight and I will come back tomorrow. 

If anyone is planning to do some locking in the meantime, you can undo the connections keeping in mind to turn off the power to the RFPDs before you do so.

P.S. I walked in this morning to PSL FSS slow actuator at 0.89 and brought it down to zero before making measurements.
I also touched the steering mirrors that are part of the Y green beat note alignment while looking at the amplitude of the RF signal on the spectrum analyzer.

RF connections to the beat note adder on the IOO rack have been undone and it should be good to proceed with any locking attempts.

The RF amplifier panel on the IOO rack (Attachment 1) will be used to also hold the RF amplfiers for the frequency counters. The amplifiers mounted on it right now are getting +15 (orange wire) and GND (black wire) from the rack power supply (Attachment 2).

Proposed plan to install RF amplifiers:

1. Disconnect the D sub connector that powers the amplifiers and pull out the panel. The rack power supplies will NOT be shut down for this. 

2. Mount the RF amplifiers with bypass capacitors. There will be 4 amplifiers ZFL-500LN mounted on the same panel (2 for each frequency counter).

3. While putting back the panel on the IOO rack, we will need to shut down the +15V and -15V sources to connect the amplifiers to the rack power supply.

I will do this over this weekend so that we dont lose any locking time. If anybody has any concerns, let me know

It is certain that we have space issues at the X end that has been preventing us from sticking in a lens to couple light into the fiber. 

The only way out is to install a platform on the table where we can mount the lens. I have attached the a photo of how things look like at the X end (attachment 1) and also a drawing of the platform that which can hold the lens (attachment 2). Additional support to the raised platform will be added depending on how much space we can clear up on the table by moving the clamping forks of the doubler.
Steve and I have been able to gather parts that can be put together into something similar to what is shown in the drawing. 

Proposed modifications to the X end table:

1. The side panels of the table enclosure will come out while putting in the new platform.

2. The clamping forks for the doubling crystal will be moved.

Let me know of any concerns about the proposed solution. 

Below is the set of plots comparing measurements for the green and IR beat notes frequencies. The measurements were made on the spectrum analyzer at the same time. So I have not taken measurement error into account. 
From the plots, the discrepancy is not very large.

Attachment 1:
Shows the two sets of measurements scaterred along y=x.

Attachment 2:
Since plot 1 shows the points tightly scattered to y=x, I plotted the difference between the two measurements against their mean to blow out the deviations.

I will do the same comparison using the frequency counter readout once we have RF amplifiers installed.

Since there will be some work that supposedly will involve moving stuff on the table and racks; here is the updated to-do list for FOL.

[Koji, Manasa]

We cleared up some optics and optomechanics at the X end table that are not being used and moved them to the SP table. [Ed by KA: They seemed to be leftover of the other projects. I blame them]

SP table has been a mess because Q and I had let our SURF leave without cleaning up.

I cleaned up the SP table, put things back where they belong and did some sorting. I will put back the optomechanics where they belong sometime later.

For now, check out the SP table next time you are looking for a Y1  or lens or BS.

Today I was around the IOO rack.

I shutdown the power to the beat PDs on the PSL table and disconnected the D sub 3w3 connector that was powering the RF amplifier panel on the IOO rack.

I moved the RF amplifier from the panel to a box that can go on the rack. The box will also hold the RF amplifiers that will be used for FOL. I have not completed putting in all the amplifiers. But the RF amplifier for ALS is in place and the box has been installed on the IOO rack for locking tonight. The power supply to the green beat PDs has been switched ON.

I took the out of loop noise measurements for ALS X and Y and the attachment is the screenshot of it (X and Y have rms of ~300Hz and ~400Hz).

I had to touch the Y end steering mirrors for green to get maximum GTRY before making thes measurments.

I pulled out the RF amplifier box from the IOO rack again and added the new RF amplifiers for FOL. 

I replaced one of the decoupling capacitors of the ALS beat note RF amplifier ; the poloproylene capacitor with a ceramic capacitor (0.1uF) .

After putting back the box, I confirmed that we had a beat note. I did not get a chance to measure the ALS noise after putting back the box because the IFO was already occupied.

I will post a detailed elog of the components in the RF amplifier box once I am done with it (hopefully tomorrow)!

The components of the RF amplifier box are in place. The RF amplifier box has been mounted on the IOO rack and the front panel connections have been labeled. Attached is the photo of how things look in the inside for future reference.

Sometime in the next few days the box will be pulled out to replace the panel mount SMA barrels in the front with insulated ones.

The X end fiber setup will be put together tomorrow morning. Let me know if there are any concerns.

[EricG, Manasa]

We were at the X end today trying to couple AUX X light into the fiber. 

The proposed plan still did not give a good beampath. The last steering mirror before the fiber coupler was sticking out of the table enclosure. I tried a few other options and the maximum coupling that I could get was ~10%

I am working on plan C now; which would be to use fixed mount mirrors and steer the beam to the space created by Koji near the IR trans path and use a set of lenses instead of a single lens. I will elog more details after some modematching calculations.

We moved one of the clamps for the doubling crystal to make space. Also, the NPRO current was reduced during this work.

I reset things to how they were before I touched the table. I ensured that the green power was still the same (~3mW) after the doubler and that it could lock to the arm in TEM00.

I pulled out the Fiber Optic Module for FOL from the rack inside the PSL table enclosure and modified it. The beat PDs were moved into the box to avoid breaking the fiber pigtail input to the PD.

The box has 3 input FC/APC connectors (PSL and AUX lasers) and 2 output FC/APC connectors (10% of the beatnote for the AUX lasers).

Attachment shows what is inside the box. The box will again go back on the rack inside the PSL enclosure.

I found the PSL enclosure open (about a feet wide) on the north side this morning. I am assuming that whoever did the X beatnote alignment last night forgot to close the door to the enclosure before locking attempts 

Plan C finally worked. We have 1.454mW of AUX X light at the PSL table (2mW incident on the fiber coupler). 

Attached is the layout of the telescope.

What I did:

I stuck in Lens 1 (f=200mm) and measured the beam width after the focus of the lens at several points. I fit the data and calculated the beam waist and its position after this lens. 

I used the calculated waist and matched it with an appropriate lens and target (fiber coupler) distance. I calculated the maximum coupling efficiency to be 77% for Lens 2 with f=50mm and the fiber coupler placed at 20cm from the waist of Lens1. I was able to obtain 72% coupling after putting the telescope together.

I locked the arms, ran ASS and brought back GTRX to its usual optimum value of ~0.5 counts after closing. We also have the X arm beatnote on the spectrum analyzer.

Notes:

There are still a couple of things to fix. The rejected beam from the beam sampler has to be dumped using a razor blade.