MAPS – Page 4 – Extreme Wavefront Control Lab

MAPS Aug. 2024B Night 3: Temperamental Temperatures

Howdy! I’m Bianca; formally I am research staff for CAAO, but you may have heard of me as one of the padawans under the tutelage of AO Jedi Knight Amali Vaz.

This is my 5th MAPS observing run and my first blog post! Last night was the most action-packed night I’ve yet to experience, so let’s start at the beginning.

This night we were joined by Jared Males and first-year grad student, Parker.
6 pm found us preparing for the night’s activities. The clouds got the opening time memo a few hours later, but they couldn’t stop us from being productive!

Andrew bestowed upon us Version 2.0.5 of mapspyindi2, which fixes crashing GUIs and optimizes setting the state of the ASM.

Amali and Lauren (my fellow padawan) began latency measurements round 2 electric boogaloo with new tuning parameters, courtesy of Jess.

Jared gave Parker the grand tour of the MMT and the run-down on MAPS.

Yoav hit a snowbank with the MIRAC detector: it was significantly below the recommended operating temperature due to the previous night’s efforts to cool the detector followed by a day without the heater on. Yoav led Lauren and I in detector-warming efforts for ~ 3 hours, estimating it would take 2+ days to reach our necessary temperature unless we could raise the power being sent to the heater by ~100%. Proving his multi-faceted savvy, Yoav introduced those of us less versed in memes to our word of the day- Cowabummer.

I’ll let this meme demonstrate it’s proper usage:

Original image from the 2015 DC Comic Batman/Teenage Mutant Ninja Turtles #4. Dialogue adapted and meme posted to Facebook in 2020 by user Raven Perez. Referenced by Yoav Rotman, which inspired yours truly to further adapt the meme last night.

Jarron saved the science day by instructing us to bypass the PID loop and send “UNLIMITED POWER!!!” (well, 100% but I’ve heard it both ways) to the heater.

Can you blame me? Of course I’m taking the low hanging fruit

Once the detector reached the optimal temperature, Yoav came in with the assist for Mara, a fellow ASU grad student, by taking data she needs for her thesis. Later, a closed-loop 50-mode K-band MIRAC PSF was also attained!

MIRAC PSF in the K band with AO loop closed!

MIRAC-BLINC temperature crisis resolved and the clouds having sufficiently departed, we switched gears to alignment and pinned down the order in which to move the 2 periscopes and move the telescope to have the star simultaneously in focus on the acquisition camera, entirely visible on the pupil imager with nominal vignetting, and centered on the pyramid. After the previous runs’ hard work and inevitable frustration that alignment was never quite right, the successful alignment was a small but significant accomplishment.

Pre-alignment pupil left, aligned pupil right: bye-bye vignette!

CACAO time! We set to collecting as many 50-mode response matrices as possible but temperature issues now decided to make the ASM its new target: and boy did she feel the heat. We alternated between taking 2 response matrices, followed by cooling the ASM for ~10 minutes until the sun commanded we cease.

The song of the night is ACDC’s “You Shook Me All Night Long”, because that’s exactly what we did to the ASM.

MAPS Aug. 2024B Night 2: Unstable

Tonight we first took a bunch of ASM latency measurements with different tuning parameters for Jess — took about 3 hours to get 5 iterations, may do more tomorrow night. (Well, this was after being closed for clouds for the first couple hours of the night, same as last night.)

Then we moved on to CACAO calibrating and testing. Amali tried closing the loop using the response matrices from last night. The 20 modes one worked OK, but the 50 modes one was quite unstable even at medium modes (10 and up). So then we tried median combining them and looking at them here. In the following plots we have 5 iterations of the 50-modes response matrix, and the 6th frame is the median. Tip looks OK, tilt looks OK, and focus looks OK. But they also have odd higher-order signals that AREN’T averaging out. Like the bright white or black volcano. However, these 50 modes were taken with the 20 modes loop closed, and what if that was introducing some noise? So now we are trying going back to the 20 modes response matrix and doing more iterations to average those. For the 20 modes response we are closing the loop on tip/tilt at 0.30 gain and on focus at 0.15 gain. We’ll just keep doing these until sunrise, then average them and try them tomorrow night.

Oh and Yoav had to run up the hill away from a bear as he was coming up to the dome from the Bowl tonight.

The song of the night is “Stressed Out” (Acoustic version) by Twenty One Pilots:

MAPS Aug. 2024B Night 1: We’re back!

Last night was the first night after the summer shutdown and despite the forecast we were open for most of the night! We’re using MIRAC as the PSF viewer and found the first star pretty fast!

We aligned the pupil, tested the rotational centering, tried the -300mm and -250mm lenses in front of the VisWFS and decided to go with the -250mm lens. Then we took mlats and then many iterations of CACAO testing. Rebooting RC3 and taking care of some of the over zealous logging seemed to help with issues of the CCID-75 seeming to pause or hang. The low is around 60deg F and the ASM sometimes gets close to overheating, so we take a short break and allow it to cool down. The night ended with a hot ASM at the first twilight.

The song of the night is “Peaches” by The Presidents of the United States of America:

MAPS Jun. 2024A Night 7: Final day and night

Today was the last day of SPIE Astronomical Telescopes & Instrumentation 2024 and tonight was the last night of MAPS June 2024A.

Joseph gave a nice talk (second-to-last of the conference) with MagAO-X data:

Joseph Long giving a talk in the PSF reconstruction session.

Meanwhile at the MMT we tested our previous CACAO calibration, took a new one in better seeing, practiced both Bianca and Lauren running CACAO, and were in the process of more testing when we had to close the dome due to high winds. We waited around until finally calling it a night and a run around 2:30am when the winds continued rising and the clouds came up too.

Here’s our pretty good CACAO loop with 50 modes.

We keep asking Tim and others from MMTO to explain the hexapod to us, but we still don’t understand some of the behavior we see. Last night we had the focus pushed to the limit (near +1600 um), even to the point where the LUT wanted to offload coma but couldn’t send it. So last night we tried starting over: We put the focus to +800 um, let the LUT run for a little while, and lo and behold we were way out of focus. As we focused by eye we ended up back near the limit, around +1600. Tonight, on the other hand, we’re around +700 um and we’re in focus. We asked Brian if the temperature correction is very different and it’s not — well it’s about 50 um different, but that’s not enough to account for the focus difference of around 800 um.

Thanks for a great conference and observing run all!

The word of the night is 満月 (Mangetsu) which means full moon.

MAPS Jun. 2024A Night 6: Pupils, CACAO, and ARIES

Today/tonight Dan and Amali went down, Dan and Oli came up, and Craig and Oli went down. Oli brought up six (6) new negative lenses ranging from f=-100 to -1000mm to test the Vis WFS pupil focus. We took another image set with the current lens (f=-300mm) and then swapped it out for each of the other lenses to see the difference in pupil focus and pupil size/separation. Here is what we saw:

Negative lens test, in front of Vis WFS.

Result: The best are f=-200 & f=-300. Oli’s feeling is the best focal length is going to be around f=-250mm. That lens is not available but can be created by combining two lenses. Furthermore, there are other degrees of freedom that can be used to fine tune… namely the separations between the CCID75, CTL, and Pyramid. By adjusting those distances, the overall magnification (pupil size and separation) will change. This is a much more complicated alignment and is destructive since a move cannot be perfectly reversed. So we may try that another time.

Meanwhile we took some ARIES spectra, then went on to closing the CACAO loop with 50 modes and saving some ARIES images. Unfortunately the seeing was around 2-3” so these won’t be great, but it was also a really good practice session for Lauren and Bianca to run CACAO while Amali coached them remotely from Tucson.

There was a dust storm blowing over from New Mexico. Around 3:45am it got worse, and meanwhile the seeing had blown up to above 3” where we were unable to make much progress anyway, so it was time to close for the night. We have 1 more night but the forecast doesn’t look promising, so we shall see.

The word of the night is TEAMWORK. The MAPS team has done a great job this run covering the various tasks even though various people have had to come and go due to life circumstances. Thanks for the excellent teamwork, MAPS team!