24-9-2024
We recently posted a paper about our 2023 run (readers of this blog may remember, the one where we accidentally turned our instrument enclosure into a melting probe). It wasn't the best run (only a week of data after about a month of commissioning, and those data ended up being contaminated with radio interference from our own electronics) but we learned a lot about the mechanics of running the instrument, and most importantly, things to improve for 2024. We made those improvements, and had a successful season this year because of it.
check it out here: https://arxiv.org/pdf/2409.07511
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18-9-2024
The data taking phase of RET-CR is a wrap.
Krijn de Vries, Katie Mulrey, and myself went to the ice to retro RET-CR after a full season of data taking. The instrument ran well, and we have a few hundred thousand cosmic ray triggered events to analyze. This means that we have several hundred thousand events where coincident charged particles triggered a readout of the entire system. A nominal event record for us contains: 4 amplified in-ice radar receiver channels, 1 unamplified in-ice radar receiver channel, (all of those are about 3.5 microseconds of data), timing and charge information for up to 10 charged particle detectors (depending on how many formed the trigger, more energetic the primary, more detectors trigger) and in-air radio data for up to 5 cross-polarized surface station antennas. Our next task is to analyze these data to see if we have radar echoes from the cosmic ray cores in there. A number of RET graduate students will lead this analysis, where we hope to confirm or falsify the hypothesis that the radar echo method can be used to detect ultrahigh energy particle cascades in ice.
Most nights we didn't have enough power to run the full system, so we took background data. And at these times, the surface stations usually went down too. But for about 2/3 of the day, we have mostly full event records. Caveats being when one of the surface stations wasn't playing nice for whatever reason. In these cases, we have event records with data from N-1 stations where N is the nominal 5 surface stations that we deployed. It is largely the dataset that we hoped to get this season, so from that standpoint we are quite happy with the instrument's performance in 2024.
Ultimately it was a great deployment, too. We had some excitement, some laughs, and most importantly, a safe and productive experience. We were able to retro everything except for a few cables that were simply too long and too buried to remove with the time and resources at our disposal. The electronics and all of our cargo has arrived safely back home, and now it is time for our analysis to begin. Stay tuned for results, hopefully in the next few months.
I'd like to once again thank the staff at Summit Station for providing us with a safe, professional, and fun environment in which to work. Experiments like RET-CR would be impossible without the dedicated efforts of techs, operators, logistics folks, chefs, coordinators, mechanics, carpenters, electricians, IT folks, and the many behind the scenes individuals making sure that we had everything we needed at every stage of our deployment. We were able to successfully deploy our instrument, take data all season, and retro, with every need met and every problem solved attentively. Summit remains my favorite place that I've done field work, and though our time there is done, I would be so happy to get the chance to work there again.
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25-8-2024
This is just a temporary placeholder post for the retro trip. It's been an eventful and very productive deployment, and we've managed to complete our retro on time. As ever, the station staff have been absolutely excellent. I'll make some posts shortly about the highlights of the trip!
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11-8-2024
RET-CR has spent the summer taking data, and it's time to retro it back home.
We've had a great season of data taking. With the exception of one broken cable, which our friends at Summit Station were able to fix in a matter of days, the system performed nominally for the duration of our data taking run. We therefore have a good dataset to analyze, which will be our task for the next months.
A more imminent task is to shutdown and retro the system, as our data taking run is nearly complete. A team is headed back north to do just that. It's been a great season, and we're looking forward to moving into the next stage of RET-CR.
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10-6-2024
As promised, a little wrap up.
RET-CR is back in action after an excellent deployment season. We were able to deploy our target instrument, and had enough time in the field to take care of some debugging and perform some calibration. All in all, it was a great deployment, which I summarize here.
I was joined on the advance team by Dylan Frikken and Simon De Kockere, RET graduate students from Ohio State and Vrije University Brussels, respectively. Our successful deployment was due in no small part to their efforts. They worked hard, smart, and safely to get the system dug out, verified, and redeployed, and it was a pleasure to work with them in the field. We put our heads together to solve problems and get the system deployed in brutally cold (but mercifully calm) weather. A bit over a week in we were joined by Alex Kyriacou, postdoc at KU, and Curtis McLennan, KU grad student, who performed calibration and ice property measurements. The measurement program that Alex devised will help us to understand the properties of the local ice at our site, which is essential for reconstructing any events that we detect, and we plan to present results from this in the coming months. We wrapped everything up ahead of schedule and left the ice together, meeting up with some friends for a meal in Kangerlussuaq before heading home.
We also owe the success of this deployment to the excellent support staff at Summit. Tots (and later Austin and Rob) was an excellent site sup. Ian helped organize our expedition, helping to consider all eventualities. Manny and Hope met our every logistical need. Science techs T and Darien helped facilitate our work, and will lend an assist in coming weeks to monitor the health of the instrument. Char kept us well fed with packed lunches and delicious dinners. David and Nick got our sleds running on the exceptionally cold (-50C with wind chill) mornings. Cargo folks, heavy equipment operators, IT folks, carps, and electricians were all instrumental to our work. Our local logistics were once again expertly handled by Jennifer Laverentz of CReSIS at KU. Rob Young, director of the KU Instrumentation Design Lab designed and built the majority of our electronics, and made himself available for remote debugging at all hours. The KU Physics and astronomy Machine Shop built our antennas, thermal management system, and more. Last but not least, the 109th Airlift Wing of the NY Air National Guard and their mighty LC-130 makes it all possible. There's no place I'd rather do science than Summit Station.
The instrument is currently healthy and taking good data. We are optimistic that we have deployed an instrument that will be able to falsify or confirm the radar echo method in nature. We need a couple months more data for that, and we're cautiously optimistic. Stay tuned.
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24-5-2024
That's a wrap. RET-CR is humming along, and the deploy team has departed Summit. I'll do a wrap-up post or two in the coming days, but for now, a bit of rest.
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21-5-2024
Nope. Today, though, surely.
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20-5-2024
RET-CR is back online. We added a 4th receiver channel down the new borehole (drilled using an excellent Kovacs system of coring drill+sidewinder) so with that, the system is fully operational. We're running at about half transmitter power as we get used to running the system, but things are running and looking good.
We ended up taking saturday to make some measurements of ice properties while deploying the fourth string, and we'll analyze those data after we get back home. The Summit field coordinators and science techs helped us dismantle our field tent, and then we cleaned up the site and finished up some last minute details on Sunday. Now we're all packed up and waiting for our flight, which should (should) off deck from Kanger in an hour or so.
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16-5-2024
Got back on the coring drill today and we drilled two more holes, one for calibration and one for another receive channel. We also did some tidying up and storm hardening, and dug an enormous pit to dig out a front-end amplifier from last season that is misbehaving. Alex and Curtis from KU started work on measuring the properties of these ice cores, so that we can better understand radio propagation in the ice at our site. The DAQ is triggering happily on cosmic rays in 5 surface stations. Good progress today.
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14-5-2024
Well, the forecast was bogus, it is bordering on condition 1 (no unauthorized travel even on station, and no off station travel) so we'll take a raincheck today on drilling etc.
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13-5-2024
Storm was forecast for today, so early this morning Dylan and I went out to the site to shore up the stand for the DAQ. It feels pretty solid now, and provides an elevated platform for the enclosure and the cables, which should (should) mean that we don't have to dig as much come August when RET-CR is retro'd. Winds are gusting to 30-35kt, so it will be a good test of the durability of the system. Definitely not worried about the PV array, the KU Physics machine shop did a great job with that one, having survived the winter. Tomorrow we drill some ice cores and deploy some antennas, and continue to debug.
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12-5-2024
Yesterday the crew assembled the rest of the surface station antennas and solar trees, and started digging out our stack of remaining scintillator panels (they are close to 2m below grade, rather than the 1m I advertised to those who'd be digging, oops) and I worked on building a platform for the DAQ so it doesn't disappear over the season. We were also having some unusual issues with our cosmic ray system that we didn't see in testing so we took steps to address that. Steady progress; the full RET-CR instrument is in sight.
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10-5-2024
Yesterday we got the remainder of the system deployed to the point where we had things running last season, transmitter, receivers, 3 surface stations. Mostly. Some bugs to chase down and fix, but things are for the most part humming along. We're hoping to drill more receiver holes and deploy the remaining 3 surface stations in the coming days. It's colder here this season than I remember from last season; this morning it was -40C, -56C with wind chill. Happy for warm lodging, and good tents at our work site to get out of the elements, both thanks to the Summit Station crew.
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8-5-2024
Today we cabled up the central station and partially deployed two surface stations. It seems like all of the transmitting antennas and cables survived the winter intact, and the system is working well. Tomorrow we finish deploying the primary surface stations and then it is time to commission the instrument. And two more RET members will join the field team tomorrow as well.
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7-5-2024
Weather didn't behave. Working on some electronics stuff today, tomorrow we'll do the full deploy, and see what needs fixed.
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7-5-2024
Yesterday we got the central system deployed, and Summit staff helped us to deploy a wireless ethernet bridge so that we can talk to the system remotely. After wiring up the power system, we plugged it all in, and things worked well. Today we're gonna try to do a more complete systems test if the weather behaves.
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5-5-2024
Yesterday the team managed to get the solar array redeployed. Interestingly, out of our nine panels that spent the winter on their mount, the tempered glass of one was completely shattered, but the rest were in perfect condition. We're a bit puzzled about it, and guessing it could be that specific panel's position relative to the predominant wind direction, because nothing else was obvious. The voltage on it still reads nominally, so we have redeployed it and will expect less efficiency from that one this season, which is fine, we have the power margin.
Summit takes sundays off so the team will get back to the field on monday.
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3-5-2024
Big day today. With tons of help from station staff, we got our deployment tents up, one at station, and one 5km away at the RET-CR site. Then, the three of us spent the day dismantling our PV array, which was pretty drifted in from last season. See above for a before and after. Tomorrow, we will re-deploy the array.
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2-5-2024
RET-CR is back north. A team of three has arrived at Summit Station to redeploy RET-CR for another season. Over the next few weeks, they'll be digging out the station from last season and redeploying our upgraded and expanded system. The goal: to get the system set to take data all summer, through August 2024. More soon.
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14-1-2024
New year, upgraded system.
Members of RET came to KU last week for our 2024 system integration test, where we did a full test run of our updated electronics (designed in house by the Instrumentation Design Lab). The main redesign was to provide more granular timestamping of our cosmic ray detector surface stations (more info on this here https://arxiv.org/pdf/2104.00459.pdf). Last year we were able to precisely time the triggers from these surface stations, comprised of two scintillator panels and a radio antenna. A single-station trigger was formed when both scintillator panels triggered within a causal window. This year, we intend to store timestamps of the single-station triggers AND the trigger signals from each individual scintillator panel. This will allow for better reconstruction of the primary cosmic ray events.
The test was a success. We captured triggers from cosmic rays using two spare scintillator panels (the rest are buried at Summit Station), triggering an event readout. We identified several bugs, squashed some, and have a few to work out before our next deployment, which takes place in April of this year. Most of the remaining time will be spent working on thermal testing and radio-frequency interference (RFI) mitigation, both of which caused us problems last year and are top priority. Results from this test, plus lessons learned from last season, have us feeling optimistic for a good run this summer (and we are, to my delight, on schedule.)
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8-9-2023
During the first Summit deployment, our team had the pleasure of visiting with Dr. Jean de Pomereu, a historian and artist focusing on the scientific and political history of Antarctica and Greenland, who was on a trip to Greenland for research. During our overlap at Summit, he documented both the science happening at Summit, and the general goings on at this remote and unique research station. He recently wrote up an article on this part of his travels for the Royal Geographical Society magazine, with photos and descriptions of the various science groups working at summit this season, and you can check it out here: https://geographical.co.uk/science-environment/greenland-summit-station.
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28-8-2023
It has been a busy few weeks.
Our retro team has just returned from Greenland, after working to recover our electronics and prepare RET-CR for the long polar night.
Katie Mulrey (Radboud University, Netherlands, field team lead), Dave Besson, and Alex Kyriacou (both from University of Kansas) made the trek to Summit Camp to verify the health of our system, pack up our electronics for retro, and winterize our equipment in preparation for another data run next season.
During the middle of our summer run, we lost contact with the station. After massive efforts by summit station staff (especially science techs Janelle Hakala and Flint Hamblin), and some of our friends from the RNO-G neutrino detection experiment, we found that our system had gone offline due to overheating. This paradoxical situation of overheating in -30c weather is one we planned to avoid via thermal testing before deployment, but as happens with first attempts, things don't always go to plan.
Our thermal testing was performed assuming that our system would be on the surface. We had intake and outlet vents with fans and filter material to keep snow out, and this setup kept the electronics at a reasonable temperature at full power. However, on arrival, we found the blowing snow to be far finer and more invasive than our design scope, and it became clear that the snow filters we installed on our vents were insufficient. So we made a decision on the second to last day of the deployment to dig a large vault in which to put the instrument. We left plenty of room around the instrument for ventilation, and covered it with plywood and snow. But of course, burying it changed the thermal environment. Snow is a fantastic thermal insulator (the snow a meter or so down in a place like Greenland hardly fluctuates in temperature all year round) and we knew that when buried we wouldn't be able to shed heat as we would have on the surface. We took this gamble because snow ingress would destroy the electronics, and heat we could hopefully manage. In the end, we overheated (RF power amps make a lot of heat), taking the system offline.
Before going offline, though, we took about 4 weeks of solid commissioning data and ~1 week of high-quality run data. Maybe there's a cosmic ray lurking in there, but it is less data than we hoped for, and not enough to fully answer our scientific questions.
Our team has now retrieved our electronics so that we can make repairs and improve the system over the winter months, in advance of our next deployment. Even though we didn't get as much data as we hoped, we learned a great deal about running an in-ice radar system (the first of its kind), and that was all exceedingly positive. Many technical aspects of the system (transmitter cancellation, steering our phased transmitter, changing transmitter power and frequency, various different triggers) worked as expected, and tell us that these technical challenges have been met, and can be scaled up. So, it wasn't a perfect run by any means, but we managed to get the system up and running for a few weeks, which I'd call a qualified success for a new instrument.
The recovery team did an amazing job setting us for success next season, and we're all looking forward to that. More soon.
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28-6-2023
I'll close out this 2023 RET-CR deployment series of the blog with a photo of our deployment team. From left to right: Rob Young, Enrique Huesca Santiago, Dylan Frikken, Rose Stanley, and myself. Another big thanks to this team, they did such a great job in challenging conditions.
I'd like to also to acknowledge some folks who made this work possible through their support efforts. These include: Jennifer Laverentz, our logistics coordinator par excellence from KU's CReSIS, who handled everything logistics from shipping to travel, no project too large or detail too small; Sam Dorsi, our project manager at Polar Field, who worked tirelessly to ensure our deployment was a success; Mark Stockham and Scott Voigt, machinists at the KU Physics and Astronomy machine shop who did outstanding mechanical design and construction our PV mounts and antennas on a compressed timeline; Aaron Paden, CReSIS machinist; Delia Tosi, Matt Kauer, and Chris Wendt of IceCube/UW for providing scintillators and extensive technical support; Christian Hornhuber of the KU Physics and Astronomy Instrumentation Design Lab (working with Rob Young [director of IDL] of our deployment team); Kristin Rennells, physics and astronomy department admin for general assistance with shipping, logistics, documentation, you name it; Stephanie Wissel, RET ombuds, helping to ensure compliance with our field manual; Bill Burley and Jeff Worth, KU electronics technicians; Cosmin Deaconu and Eric Oberla, for troubleshooting our IT efforts and data management in the field, and for custom electronics design and troubleshooting respectively; Patrick Allison, who made critical contributions to hardware, software, and firmware in the lead up to deployment; Kaeli Hughes for diagnostics and RF expertise; Summit Station personnel including Austin Danicic, Brian Dornick, Ian Geraghty, Dino, Tom, Jeremy, Mark, Char, Hope, Tots, Diana, Forest, Derek, and especially Alicia Bradley, our science tech who made numerous excursions to our site to solve critical problems. Many others contributed their time, thoughts, and expertise to the project, enabling us to do our jobs safely and get the experiment online---the project simply could not have happened without these efforts. I'd finally like to acknowledge support for RET from the National Science Foundation (our Particle Astrophysics program officer, Darren Grant, and Renee Crain of the Office of Polar Programs), the European Research Council, and Institute of Physics (IOP), and to personally acknowledge support from the IceCube EPSCoR Initiative, and the John D. and Catherine T. MacArthur Foundation.
Stay tuned for future posts in August about our retro deployment, and some discussion of our future plans, and maybe even some results. maybe.
(photo credit: Alicia Bradley)
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9-6-2023
Dylan on the coring drill!
Here we are drilling the hole for our transmit string. Tough to see, but we have a power drill attached to a spool of rope, attached to the coring drill extension train. That's a clever system that lets us use the same power drill to lift the coring system via the hinged pulley platform below. This hole went to about 14m, and we deployed an 8 antenna phased array down to the bottom.
(photo credit: Enrique Huesca Santiago)
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5-6-2023
Rose on the coring drill!
Here we are drilling a test core, to get a feel for the coring system. Rose is using the t-handle, which provides more control, but when Dylan and I drilled the antenna holes, we used a powerhead to speed things up.
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2-6-2023
A couple of years ago it rained at Summit for (i think, not an expert) the first time in recorded history. They have had 'melt events' where it has risen above freezing a handful of times in the historical record, but rain is unheard of. When we drilled our test core we came across this layer of ice, and according to a casual conversation I had with a glaciologist present at Summit, it was at about the right depth for that event. cool to see in the core. not cool that it rained at Summit.
This is part of an ongoing area of research in the UHE neutrino community: how do ice properties affect radio propagation in the ice sheet? Clearly layers like this will have an effect on signals. A few years back RET developed some software to model radio propagation through realistic ice profiles (albeit in 2-d) called paraPropPython, and we're using that to study what effect things like melt events and inhomogeneities in the ice will have on our radio signals. These largely local effects are very important to understand if we hope to be able to accurately reconstruct the properties of the primary particles that produce the radio signals that we measure. Between their source and our detectors they go through the ice, and that has an effect on the shape of the signal we receive.
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30-5-2023
A word on gear.
In the extreme cold, good gear is important for staying safe and getting work done. Temps at summit were -20 to -30c, with wind chills down to -40c while we were in the field. That, combined with a pressure altitude of 11,800ft some days, mean that the elements can get on top of you really quickly. Gotta stay prepared.
My team did a great job getting kitted out, and we all had our own approaches. Some of us had traditional parkas meant for extreme alpine environments: these were excellent for warming up and enviable when doing tasks that required standing still in the wind: the biggest challenge for cold weather gear. Others relied on layering. I had a technical wool base under a wool sweater and regular canvas trousers, insulated canvas bibs, a down hoody, augmented with a canvas work coat outer when it was super cold. I had some (admittedly silly looking but excellent) 3-finger glove/mittens that gave me warmth and dexterity, will definitely use again. Dylan relied on his well-tested ice-fishing gear from his days in northern Minnesota to good effect. His bibs have waterproof construction and padded knees: very well suited for our drilling and assembly work. There's a ton of ways to kit out, it just has to be comfortable and functional for the user.
Above are my favorite piece of kit: my used army surplus mukluks. Basically a canvas upper with a soft rubber sole. Inside each boot are 2 felt insoles and a warm felt liner (better than the one they come with). With these, I wore (forgive me) a basic cotton sock and that's it. Perfectly toasty in all conditions mentioned above, including kneeling and standing on the ice all day long. My understanding is that the key to their success is their ability to breathe. They don't let your foot sweat, and the air within the boot insulates. I think also that the frost layer that builds up on the outside has an insulating quality as well, maybe. They are super light and so comfortable, like wearing slippers. This incarnation is a modern application of indigenous knowledge; arctic peoples have worn mukluks made from animal skins for aeons, with the same principle of operation. Accept no substitutes.
(p.s. to anyone at Summit reading this: I found my hat! It was about 2 miles from Summit on our snow machine route.)
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28-5-2023
Drilling was challenging, but satisfying. We had a 15cm diameter coring drill and struggled to break the core free and retrieve it beyond about 12 meters. This is likely due to a combination of factors (including, above all, user inexperience) that we could troubleshoot better if we'd had more time. Given the constraints, we modified the drill plan to drill to 10m for each hole (14 for the TX, so that the phase center is at 10) and have 3 RX strings rather than 4, given that we had to complete all of our drilling in just 2 days, which we did. The above photo is taken down the borehole with the drill about 2 m down. Below that, it's too dark for a photo.
Modifications of the field plan are important in field work, so long as they still allow you to get the required physics out. We had made some tentative triage plans in the event that we lost some time due to weather or 'north winds' (when the wind blows from the north, station operations cease due to clean air science happening south of station), and we unfortunately had to activate basically all of those plans during deployment. We lost a bit over 2 days to the flight delay, and then another 2 days cumulative from high winds.
A critical issue I did not consider, and this is a symptom of my own inexperience in designing a polar field plan, this being my first time: we had plenty of total margin in the schedule, but NOT at the right time in the schedule. Meaning, if we'd lost 4 total days toward the middle of the deployment, it would not have been a problem. But losing them right at the start like we did meant we could not complete the downstream tasks (cabling, trenching, commissioning) that relied upon the more physical infrastructure tasks (drilling holes and deploying antennas, getting power going via the PV array) that required good weather. We likely would not have needed to de-scope had we been a bit more lucky with the timing of lost days.
So we learn. As deployed, the system has 3 downhole RX and 3 surface stations. The TX is a complete 8 antenna phased array, and I'll post a photo of that soon. I also took a video of us deploying that string, which was a full team effort. Unfortunately I did not film the raising of the PV or any drilling (no time to think of documentation, even though it is so important!) I sadly don't even have a photo of Dylan drilling, even though he was on the drill the whole time (I was on rigging/lifting duty). Maybe someone else got a photo, I hope, he did an excellent job in tough conditions.
We made the absolute most of the time we had thanks to inestimable efforts by my team, and the station staff at Summit. I really can't say enough about how excellent they all were, from heavy equipment operators to mechs to carps to cargo ops, station management, and science techs, not to mention our fellow science teams; just phenomenal.
(final sidenote: my favorite part of drilling was fixing a mistake. I managed to drop a pin (used to connect extensions onto the coring drill train, you can see one in the photo) down the borehole at about 10m. We then took another core, and sure enough, the pin was sitting in the coring chips inside the drill when we ejected the core. Was nice to know there's some margin for error.)
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26-5-2023
Once the weather cleared, we cleaned the panels of snow and got them all lifted and bolted together. The KU machine shop designed and built the PV mount, and it worked really well. We dug shallow holes for the feet, and then fixed stops to keep them from sinking in further. Corner brackets and internal bracing keep the array rigidly connected, while guy lines affixed to dead man anchors provide bracing from the wind. Here Dylan, Rob, and Rose work on the bracing and guy lining, shown in-progress.
The day after we got the array up, weather moved in and gusts of over 35kts pummeled the site. The array held up just fine.
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26-5-2023
The panels, after assembly, got massively drifted in before we could raise them. The above was the state of the panels after weather came through the day after this section was assembled. Drifting at Summit is intense and happens quickly; anything above the surface becomes subject to it.
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23-5-2023
For anyone following along, I apologize for the lack of updates, things got unbelievably busy. All I can say now is: we have a working cosmic-ray triggered radar system deployed beneath the ice near Summit Station. It isn't exactly what we designed, and there were massive hurdles to clear, but we are currently taking good data.
In the coming days I'll do a day-by-day recap of our efforts. It was a massive amount of work, and tremendous efforts by Rob, Dylan, Rose, and Quique were required to get things done. The station staff at Summit were absolutely incredible. So kind, competent, and supportive. In fact, they were all of these qualities---and more---in measure well beyond my wildest expectations.
I'm currently en route back to the states, and will post more soon. Including more photos. The above is a quick snap before our final departure from the site. It does not quite give the scale of the array, so I will post more and better photos soon.
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17-5-2023
Today was a big day. We drilled 3 receiver holes, got the PV array completed (though not raised fully, because of wind) and our surface antennas assembled and ready to deploy. The above is probably pitiful (in both consistency and quality) to a glaciologist, but that's the result of our coring for one of our receiver strings. Dylan and I were on the drill all day, interested to see what my back has to say about that tomorrow...
Tomorrow: raising the PV arrays, cabling, networking.
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15-5-2023
Managed to get our first hole started this afternoon, drilled to about 12-13m. It's a good system, bit of a learning curve, but nice equipment. We also managed to get started on assembly of our PV array. More drilling and assembly tomorrow.
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15-5-2023
It's going to be a very busy day, so I likely won't have time to update. I'll try to do so later in the evening if possible!
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14-5-2023
Great day at the site. We verified the station layout and laid the groundwork for drilling to start tomorrow, and for setting up our PV system. The fight delay was a setback, but we're working to make up ground. Feeling good.
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14-5-2023
Headed out to see the RET-CR site this afternoon, looking forward to getting eyes on it for the first time. Will post some photos of it later this evening.
Also, can't text from up here so happy mother's day, mom!
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13-5-2023
Made it! This place is incredible. Met a bunch of folks today, got the lay of the land, and some tasty dinner. Rose and Dylan gave us a tour of the mobile science facility (MSF) where we'll be doing our more sensitive electronics work, and the above is the Big House, the heart of Summit Camp.
All settled in now to our luxurious accomodations (not joking) and it is time for some rest. Looking forward to learning more about this amazing station and the people who call it home in the coming days. And of course, getting RET-CR into the ice. For now, sleep.
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12-5-2023
Boomerang. We flew out of Kanger this morning and ended up circling Summit Station for an hour before turning back. Weather came in and they decided it was unsafe to land. Will try again tomorrow.
I boomeranged my first time going to Pole, too. That time, myself and and another of my team noticed that we were turning on the way to the Pole from McMurdo, a route that I'm pretty sure is something of a straight shot. I looked questioningly over at the airman, who held one finger aloft and spun it, indicating we were turning back. He then pointed at the starboard side of the aircraft. Walking over and looking out the window, I saw that one of the 4 props was motionless. Apparently we'd sprung a leak, and they decided to turn back, lacking the facilities to fix it at Pole. The Herc is so powerful that none of us even noticed the engine go down.
Today there was no such mechanical reason for turning back, just wind at Summit that decided to act up.
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11-5-2023
Scrubbed. Weather up at Summit is nasty today so we were delayed for a while and then flat out cancelled. Hoping for an update later this evening about our next attempt to head to the ice.
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10-5-2023
Plan is for a Summit flight tomorrow morning, bags are already there. "bag drag" is where you take everything you won't be carrying on or wearing (basically your checked luggage) and give it to the Air National Guard to stage the day before the flight. Guidance is usually to pack a "boomerang bag" in case the flight gets delayed--or turned around (boomeranged) in flight--so that you have a change of clothes etc. Looking forward to having a reason to wear all this cold weather kit I brought with me...
Summit station is a high-elevation field camp, so the first order of business is to acclimate. We'll take an easy day or so to getting things like our network set up, and other activities that don't require too much physical labor. After that it's go-go-go. We have an ice core drill that we're using to drill our ~20m boreholes for our antennas, and we'll start on that in tandem with the deployment of our power system and other equipment. Dylan and Rose have set the stage for our arrival and we're looking forward to getting up there and getting started.
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9-5-2023
Made it to Kangerlussuaq (Kanger) via the mighty LC-130 pictured above. Had a quick pit stop for fuel on the way, and here we are. Rob Young (Director of the KU Instrumentation Design Lab) and I met up with RET grad student Enrique Huesca Santiago (VUB, Brussels) here at the local dormitories, had a bite to eat, and it's time for some rest. Bag Drag is tomorrow at 1500 for our flight to Summit on Thursday.
Tomorrow I'll do my best to write a bit more about our plan for the field work. We have drilling, assembly, networking, and commissioning to finish, so it's going to be a crowded---and fun---deployment.
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8-5-2023
Headed north. Scotia->Kangerlussuaq->Summit Camp.
Our advance team, RET graduate students Dylan Frikken (OSU, US) and Rose Stanley (VUB, Belgium) have been deployed for about a week, working hard, alongside the wonderful station staff, to get our site prepped for the full deployment of RET-CR. They've put us a couple of days ahead of schedule through their industriousness, meaning we can bank a couple of potential bad weather days down the line. Their primary tasks so far have been a) to inspect and test the integrity of the electronics, b) to move our thousand or so kg of deployment cargo the 5ish km out to our science site, and c) to start the layout of the station and begin calibrating our cosmic-ray detectors for the high altitude. They've done excellent work so far, and will feature more in this blog as we go.
Bags are packed, coffee is hot, covid test is negative. Time to go!
(photo credit: Rose Stanley)
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18-3-2023
It's been a very busy few months. Collaborators from the US and Europe came to KU to do a field test of some of our equipment in January at the University of Kansas Field Station. The above is a test installation of one of our solar mounts in the field, along with some electronics beneath a folded tarp to keep them out of the winter weather. The fine folks at the field station prepped the site for us to make it easy to deploy.
We didn't get as far with the test as we had hoped, but we learned a lot about the system, and debugged several interface points between different components in our system. That's the way experimentation tends to go in my experience; you make designs, build components, test individual parts of the system, and then at integration, unexpected bugs happen. Often, debugging leads to better approaches for the final configuration, as it did this time. In our specific case, being a prototype/pathfinder experiment, we are using some off-the-shelf electronics, some custom electronics, and some borrowed/gifted electronics from other similar experiments that had already done the development legwork for similar problems. For such systems, the individual components often work very well, as is the case for us, and the complexity lies in getting everything integrated and working well together. We've got this (mostly) sorted out now.
Finally, deployment is imminent! We got the "go" from NSF to deploy our experiment at Summit Station, in Greenland.This is almost exactly as far away from our proposed deployment site (Taylor Dome, Antarctica) as it is possible to get on Earth, but it satisfies all of our scientific requirements (lots of ice, high altitude, remote). We are working hard to ensure that our experiment doesn't interfere with other experiments already running at Summit Station (RNO-G, another ultrahigh energy neutrino experiment, operates in a similar RF band at Summit Station), while also preparing to take enough good data to confirm or falsify the radar echo method for in-ice neutrino detection, which is the ultimate goal for RET-CR.
We deploy in May.
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22-12-2022
The Radar Echo Telescope (RET, see radarechotelescope.org for more info) is in the prototype stage with our in-ice cosmic-ray testbed, RET-CR, in advanced stages of development. We are planning an in-field integration test in Kansas to test the various subsystems working together.
RET-CR attempts to record a radar echo off of the in-ice cascade produced by an in-air cosmic ray shower. For cosmic rays of sufficient primary energy (above 10 PeV or so) a significant enough fraction of the primary particle energy reaches the ice in the form of high energy particles, and a secondary cascade will occur within the ice. We can use this secondary in-ice cascade as a test beam to see if the radar echo method is a viable way to detect high energy particle cascades in the ice.
RET-CR consists of surface scintillator stations that trigger on charged particles from downgoing cosmic ray air showers. If these showers indicate a primary cosmic ray of sufficient energy they tell the main data acquisition system (DAQ) to record data. The DAQ is constantly transmitting a radar signal just below the surface of the ice. When it gets a trigger from the surface system, the signals in the receiving antennas (also below the ice) are recorded.
The upcoming test will be the first integration of the power system (solar), the surface systems (scinitillator panels, a radio antenna, and a system board capable of forming triggers and shuffling data and commands to/from the central DAQ), and the central DAQ itself, though with only one transmit and receive channel, rather than the eventual 8. The goal of the test is to get a successful full-chain event, meaning that the surface system detects an air shower and forms a trigger that prompts a readout from the central DAQ, all while powered by the solar system.
Overall it should be a good test of where we're at in preparation for an imminent polar deployment. I'll be happy if the individual subsystems each work independently, but will be very pleased if we can complete the full event readout. After that point it is simply a matter of scaling up to the full multi-station system.
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This material is based in part upon work supported by the National Science Foundation under Grant Numbers PHY-2012980, PHY-2306424, and PHY-2012989
Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.
Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.