hello, welcome to the blog. newest posts on top. scroll down for posts about our current (summer 2024) deployment of RET-CR to Greenland.





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.

-s



21-5-2024

Nope. Today, though, surely.

-s



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.



-s



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.

-s



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.

-s



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.

-s



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.

-s



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.

-s



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.

-s



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.

-s



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.

-s



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.

-s



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.

-s



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.

-s



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.)



-s



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.

-s



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.



-s



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)

-s



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)

-s



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.

-s



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.



-s



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.)

-s



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.)

-s



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.

-s



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.

-s



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.

-s



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.

-s



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.

-s



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!

-s



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.

-s



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!

-s



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.

-s



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.

-s



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.

-s



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.

-s



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.

-s



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)

-s



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.

-s



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.


-s



26-12-2017


The herc flight out was just passengers, so it was nice and roomy. we could get up and wander around, stretch the legs, and there were some tremendous vistas to be had too. here is a view of some mountains in what i assume is victoria land, where the trans-antarctics start/end. might be wrong though. in any case, it was a beautiful sight to say goodbye to the magnificent continent of Antarctica, which i truly hope i get to one day set foot on again.

-s



26-12-2017


this is a good time to give some recognition of our leader on this mission, Christian Miki. above is a picture of he and i, just after boarding the otter after completion of our mission, fully stoked on a job done. Christian's plan to retrieve the DAQ box worked perfectly, and his schedule had enough room in it to account for the somewhat significant delays endured by the program this year, so that we got the work done and were able to get out on time. His leadership was stellar-tough when need be, willing to listen to ideas, and infinitely patient. And at the end of the trip, he ensured his team had higher priority to get off the ice than himself. I'd work for him again any day.

-s



26-12-2017


here is a fun photo. out at the A4 site, odds are if you walk prettymuch anywhere, you're the first human being to ever set foot on that spot. so we took turns walking a little ways out. behind, as in front, is only the straight line of the horizon.

-s



26-12-2017


on the first morning back in McMurdo, did another hike of Ob Hill, Eribus was showing off for us again.

-s



26-12-2017


now back to civilization and reliable internet, i'll post a few of the oft-promised photos.

above is a panorama taken just before the otter arrived to pick us up the final time. in the foreground you can see the remains of the pit that ANITA rested in, and further on the last of the instrument staged for removal, and our trusty expedition tent, which we took down moments after this was taken. as you can see, there is nothing in any direction, all the way to the horizon.

-s



23-12-2017

departing NZ. as it happens, i managed to catch the McMurdo crud on the way out, spent the last day and a half recovering. someday i'll need to spend some quality time with this beautiful country.

en route back home. it's been a blast.

-s



21-12-2017

arrived in lovely NZ. a bite to eat then some sleep. will elaborate on our journey tomorrow (it was good).

-s



21-12-2017

Departing Antarctica. we have a transport at 0945 local coming up soon, and with a bit of luck, we'll be on our herc to NZ. it's a 9 hr flight heading north.

what a trip. a bit under the weather here (the crud finally got me) but i'm in good spirits. ready to go home but grateful that i got to see this amazing place again.

next post will be from lovely NZ.

-s



18-12-2017

well we've been busier than i expected, getting cargo ready etc. but now we are officially finished i think. our cargo is all back in McM and sorted and placed into shipping containers. so, we're done, it seems. time to head home.

we're nominally on the flight out on the 21st, but we'll see if the weather plays nice...

-s



15-12-2017

Back in McMurdo! had a nice flight and arrived around midnight. The internet is better here so i'll attempt some uploads of south pole goodies when i get some free time, probably this afternoon/evening.

sad to leave pole but happy to back in McMurdo!

-s



14-12-2017

got a flight! we depart at 2100 local, so we'll be in McM by midnight. It's a wrench to leave here, it's such an amazing place. but our work is done, it's time to go. my next post will be from McMurdo station.

-s



13-12-2017

canceled again! i feel guilty using station resources now that our work is done, but i must admit, i'm totally cool being stuck here for a couple days...

-s



12-12-2017

oops, nope. we get one more day of south pole time (weather). re-manifested for tomorrow. i think it's time to catch up on some long overdue work...

-s



11-12-2017

The final antennas were gathered today. our work here is done. manifested for a flight to McM tomorrow. time to say so-long to this magnificent station that i've been so lucky to call home for the last 2 weeks.

-s



10-12-2017


the final view of the site as i boarded the twin otter. the crater is where ANITA used to be, and the 3 antennas are all that's left (too bulky to fit on that flight, they'll be gathered in short order).

-s



10-12-2017


working on the payload day before yesterday. (c. miki photo)

-s



8-12-2017

done.

the entire ANITA payload is back at south pole station (except for 3 antennas which didn't fit and will be picked up by the pilots in the coming days). every nut and bolt is accounted for and the site is clean. amazing day. exhausted. will post photos tomorrow.

-s



7-12-2017


fingers crossed we're going back into the field tomorrow. the wx was bad today, but I was glad for the rest. another 12 hour day at the site tomorrow with KBA flight support shuttling kit once or twice during the day will finish off the payload.

ideally this time i'll have a chance to take some more photos, i'd like to make a panorama of the site. will try to do that first thing if i have the time. for now, here's a photo of the ANITA4 recovery team at the ceremonial south pole that we took a couple days back.

-s



6-12-2017


yesterday was a success. we managed to retrieve the main ANITA instrument (DAQ) box, which was in a very difficult position, as you can see from the photo. in the red square is a box that weighs 800lbs, inside of which resides all of the ANITA electronics. as you can see, it's roughly 15ft off the ground in the way it came down. Christian's plan was to attached a line to the apex of the obvious ring above the DAQ, set a 'dead man' anchor (just a heavy piece of metal or wood buried in the snow perpendicular to the line that needs anchoring) and pull it over with a come-along. it took several hours but we managed it, removing antennas as we went. finally, we were able to remove the DAQ from the payload and lower it onto a low-friction sled, to bring it to the Twin Otter. getting it inside was another matter-we had to get creative, and our marvelous pilots were indispensable in their assistance.

overall it was one of the mort exhausting and exciting days i've had. the otter dropped us off out there and then came back 2 more times to ferry gear. looking around in any direction, all you could see was a clear line on the horizon, where ice met sky. it was breathtaking. and we completed our task, which was to secure the instrument.

a couple more flight days ahead, hopefully, to get the rest of the instrument. but on this expedition, the DAQ is the biscuits, all the rest is just gravy.

-s



6-12-2017


polheim.

-s



6-12-2017



-s



4-12-2017

finally the day we've been waiting for-looks like we are flying tomorrow out to the A4 site. we're on schedule to depart around 0900 local, which will put us to the site by 1000, and then it's a full day's work to get the payload as disassembled as possible. the KBA pilots did a fly by for us today and took some pictures-the payload has some heavy drifting in some places, but overall it doesn't look too covered. so we will hopefully be able to make quick work of getting the crucial parts off in the first part of the day.

i will take photos of the process and will post some tomorrow night.

-s



3-12-2017


this place is as close as i will ever come to living on a space station. i'll talk more about this amazing base in future posts but here's a photo of the station from this afternoon. i'd just been given a tour of the south pole traverse 1, which just made it from McMurdo to the South pole, after 25 days hauling over 100,000 gallons of fuel to stock up the south pole base. it was amazing to hear the traverse crew talk about their process of making it to pole not only safe and healthy, but hauling an immense amount of fuel and cargo. they'll stay long enough to unload their cargo and do some maintenance on their enormous vehicles, and then head back to McM.

-s



2-12-2017

well it's a scrub for today. The pilots want to get the other group out into the field first because they are more resource heavy, so it's a couple days off for us. gonna get in some chainsaw practice (needed to cut ice blocks etc in the field) and some more tours of the place. will post photos if i take any good ones.

-s



30-11-2017


the last two days have been really amazing. we made it to station a little after midnight early wed morning (NZ time), had our in-brief, ate some food, and crashed. our accommodations are cozy, clean, and very comfortable. each person on station has a private room with a small bed, some drawers, a desk and an internet connection. some rooms have windows, some don't, and there are advantages to both. seeing outside is nice, but having total darkness is good for sleep. i have a window, but have been able to get good sleep since arriving.

the altitude is interesting. the physical altitude is 9300ft above sea level, but the 'physiological altitude', meaning what the barometer actually reads due to the changing atmospheric conditions averages at 10600ft. so it's easy to get winded the first couple of days, and i've been grateful for our leisurely schedule. we are waiting for two things: our cargo (tools, ropes, pulleys, survival gear etc.) and the plane to take us to the site, a Ken Borek Air twin otter. ideally our cargo will arrive on the herc flight late tonight, and, if the twin otter arrives too, we *may* get a reconnaissance flight out to the ANITA site tomorrow. we'll be able to assess the ice/snow loading situation on the payload, and make plans for subsequent flights. once our cargo has been processed and sorted, which will probably take the day tomorrow, we will have our equipment to make a full disassembly of the ANITA payload over the course of next week. but of course delays are expected.

so since we've had nothing to do, we've had plenty of time to rest, hydrate, and acclimatize. i was given a tour of the IceCube neutrino observatory headquarters by one of the physicists working on a new data acquisition system this year, which was really amazing. IceCube is one of the crown jewels of neutrino physics, and has detected the highest energy neutrinos to date in its cubic kilometer array. it was amazing to see the data processing center and get a sneak peek into upgrades to come.

we are sharing our flight days with another experiment and so will likely have the odd off day from time to time over the next week. hopefully i can get out to the south pole telescope site and see what they are up to as well, they are doing some upgrades this year, and their primary science mission is really fascinating. with observations of the cosmic microwave background, they can deduce the neutrino mass hierarchy, imagine that!

i'll try to put up some photos. the internet here is provided by several different satellites, and they provide reliable (and shockingly fast) internet for about 8 or so hours a day, currently from around 8pm-4am local. above is a photo of yours truly at the geographic south pole. what an immense experience it is to stand here!

-s



29-11-2017

Made it to the south pole, it's absolutely spectacular. great flight, very tired, it's been a long travel day, but i'll try to post some photos tomorrow.

-s



28-11-2017

it's a boomerang! about an hour into the flight one of the engines sprung a leak so they shut it down and we turned back around to McM. they don't have the facilities at pole to do repairs, so they turn around for things like this.

however, they haven't fully canceled us as it may be a simple repair. they have a possible transport time for us at 1815 tonight, in about 3 hours. i'm cautiously, very cautiously, optimistic.

-s



28-11-2017

scheduled to depart at 1100. wx looks clear. next post will be from pole, ideally!

-s



27-11-2017

scheduled for a flight tonight, but word on the street is we're not going till tomorrow. which is a bummer, because the weather tonight looks good. we'll see.

-s



26-11-2017

i should add for reference in the picture below that the mining town looking thing in the middle is McMurdo, the big mountain is the Mt. Eribus volcano, the cross on the right was put up for Scott and his dudes who died coming back from the pole and the green buildings (if you have good eyes) comprise the kiwi base. out on the ice shelf you can see various ice roads.

-s



26-11-2017


bag-drag complete. took a nice walk up 'ob hill' yesterday during perfect weather, took the above pano. forgive the bad stitching.

flight is slated for tomorrow evening/night. here's hoping for good wx.

-s



25-11-2017

Today is the thanksgiving feast down here so just about everyone on station has the day of. it's a nice atmosphere, everyone is relaxed and enjoying the very nice weather. although those who have been stuck at McM trying to get to pole (one group has been delayed over ten days i think, with their luggage already checked in, living out of a backpack) probably wish planes were flying in this good wx.

the anita recovery crew is manifested for a flight monday night, we bag-drag at 1900 on sunday. so here's hoping for good weather.

-s



24-11-2017

Did some training this morning for antarctic field safety. apparently, if your group is not explicitly planning on spending the night in the deep field, you don't get to do the 'happy camper' in-field training, where you build a snow shelter and sleep in it overnight. we had it on our pre-deployment brief, but they decided we didn't need it. alas. but we did take a course this morning about general field safety.

blowing snow here, going back and forth between condition-3 (normal weather) and condition-2 (not so normal weather). this afternoon will be spent in chainsaw training, gear packing, and then relaxing. we have the full weekend off, since there are no flights for the thanksgiving holiday (which they take tomorrow, saturday here) and sunday. so it's time to get in some hikes!

-s



22-11-2017


and finally, a shot of the plane from yesterday's flight. very nice! i'll post some nature pics once i get them uploaded.

-s



22-11-2017


oops, apparently i had already uploaded a different photo with the same name, so now that shows up. that's actually a photo i took last year. oops. i'll try to remedy that at some point (not so simple with slow internet). here's 3 of our number, Christian, me, and sasha on hut point.

-s



22-11-2017


some morning orientation stuff, and then a nice walk out to hut point and a tour of discovery hut (Scott's original structure in the area). i've been in there once before but jumped on the chance to get in and see it again. the smell is amazing, it's still filled with carcasses and whale blubber left frozen for a century, and there are artifacts from the original occupancy. It's been well preserved by the New Zealand historical society.

it's the thanksgiving holiday coming up which shuts things down for a couple days. flights are backed up to the pole, so who knows when we'll make it out there. ideally it will be on the weekend, but nothing is for sure.

the internet situation at McMurdo is spottier than last year (no wi-fi in the dorms) so i don't want to hog the ethernet cable too long. but, i did say i'd post photos, so here's a simple interior of Scott's hut. i took some photos of a mother seal and her cub (E let me borrow her telephoto lens this year) so once i get that transferred and shrunk, i'll post it too.

-s



21-11-2017

Made it to McM. we got a flight on a RNZAF 757, which was tremendously comfortable, with windows, no less! landed on a very well-groomed ice runway and had a nice ride back to McM. dinner, drinks, catch ups with old friends, and now bed. we have some early training at 0730. i'll try to post some photos from our trip and landing tomorrow, i'll have time in the afternoon. it's so great to be back. now it's time to sleep.

-s



21-11-2017

looks like we're gonna fly after all! all checked in and waiting at the antarctic passenger terminal...

next post will (ideally) be from McMurdo.

-s



21-11-2017

On a 3 hr delay in CHC. same thing happened yesterday and we were then delayed 24 hours...let's hope the same doesn't happen today.

-s



20-11-2017

Flight south delayed until tomorrow.

-s



18-11-2017

Made it to lovely Christchurch, NZ without issue. Lots of people here waiting to get to the Ice, the weather has caused some pretty serious delays in personel and cargo transport. But hey, that's polar ops.

The recovery team is nearly assembled here in CHC. With some luck, we'll make our monday ice flight.

-s



17-11-2017

In houston. i still have about 4 hrs till my flight to NZ. overnight flight, which is nice. apparently flights from CHC to McM have been backed up for days. could be looking at a couple days impromptu NZ vacation coming up...

-s



13-11-2017


heading back south. ANITA-4 has spent the long polar night roughly 100km from the south pole, and now that the sun is up, it's time to go get it. With assistance from Ken Borek Air, 3 of my colleagues and myself will make the trek out there to dismantle the payload and transport as much as we can back to Amundsen-Scott base, to be brought back north.

no science for me this time, just a good adventure. I'll post here about the challenges of sticking to a schedule in the polar regions (difficult) and the process of dismantling a high-altitude balloon payload after it has returned to earth and spent the last year in < -50c conditions. I've been told that internet is, obviously, limited at pole but i will try to post as many photos as possible here.

of course tangentially i will discuss some of the science going on around me. I've been part of developing a high-voltage pulser this year to do some tests of ice properties at the south pole. this time instead of launching on a balloon, it is to be lowered down an ice core. The ARA and ARIANNA experiments will use this pulser to measure various RF/ice properties of interest to high-energy astroparticle physics. I won't be doing the experiment myself, but i'll talk a bit about it, and if luck has it, i'll be able to see it in action.

i deploy on 16 nov, and if all goes well, should back before year's end. i am overwhelmed by my good fortune-returning to Antarctica was something i wasn't sure i'd ever get to do again, and this time, it's the south pole. imagine that! once more to the most spectacular place i've ever seen. stay tuned for dispatches from the ice...

(image credit C. Miki)

-s

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.