There was a mission underground, so they sent some explorers down...
I spent all of yesterday on a trip to the Soudan mine in the extreme north of Minnesota, in fact the farthest north I've ever been. Had to get up at 6:30, which I don't think I've done since high school. The coach bus was about half full with participants from the Dark Side of the Universe conference we've been hosting here all week. There was one (1) female. It was a 4-hour drive up to the town of Soudan, if it even counts as a town - I saw a couple houses, the path to the mine, and a building labeled "Soudan's Only Store." We arrived and ate lunch delivered from what I imagine is the only nearby place that does delivery, Tower Pasties. Of course, they delivered pasties. They were hearty and meaty and sort of bland, but I liked it. Contrary to initial reports, it turned out there actually was one vegetarian among us, so I guess he just ate the cole slaw.
We got our hard hats and entered the descending cart in groups of about 10. The door locked, we went down a bit, a gate slammed over our heads, and we began the alarmingly fast drop to the bottom, half a mile down. There was a dim light in the cart, so I could see the rock wall flying past. Bumpy ride, very cramped, and it lasted about 3 minutes. The guide for the historical tour was too emotionally involved (his granfather died from mine-work at 41, his son's working in a mine now) and was mega-lecture-y, telling us how our pansy physicist problems/bad days can't compare to what they put up with. Still, the mine-cart train ride was very Temple of Doom-y and the climb up a tightly wound spiral staircase into an actual non-vetilated stope and the ensuing several minutes of talk in complete darkness was sort of neato.
After this, we split into 3 groups and toured various things on the lab side of the lowest level. Just outside the lab entrance there were dozens of bats on the walls and flying around. Several also have made it into the lab area and "dead bats in the detector" becomes a real concern. A geologist was doing funky simulations with gOcad to figure out what media specific neutrino events passed through based on the incoming angle (useful to MINOS), and also preliminary work for DUSEL, which is going to do some sort of study of archaea and bacteria underground, in the rock. They claim there's more biomass under the earth's surface than above it, for one thing. Clearly they're insane.
Next was the MINOS tour, a test for neutrino flavor oscillations, and something there's a possibility I'll work on in the next couple years. The giant mural was very impressive, as were the 460-something huge detector planes, set up with two computers per plane. Also, one of the computers in the electronics control room had 6 LCDs attached to it, which was completely ridiculous-looking. There were talks on the main injector and the near detector at Fermilab and how they managed to get all this huge equipment down the little mine shaft; we watched part of a DVD of lots of things being welded together. None of those detector planes touch the ground, by the way - the weight would possibly cause buckling, which would screw a lot of things up. They're all suspended from the ceiling by huge beams. Unfortunately, they only get a couple events per day, which is sort of boring. By contrast, CDMS is more exciting with a couple events per minute, and that's what we saw next.
I already sort of knew what the general experimental setup was, but I was still pretty impressed. They have a completely automated helium transfer process for the dilution refrigerator that keeps it at 40 mK for years at a time (an ADR like the ones I used in Madison can't be kept cold nearly that long - salt pills are wimpy). The actual detector assembly that holds the five towers was completely sealed off in a clean room you can barely see into, and everything was in general way more professional than I'm used to seeing, though all the heluim dewars and cryogenics equipment made it feel more like home. In the entire lab part of the bottom of the mine, air is curculated and kept at 72 degrees, water is easily accessible, and I think I'd be just fine doing a week-long shift there, "pressing the buttons," as I may do later this summer.
We returned in the shaft cart, just as quickly as we descended, then drove on the bus for 2 hours before hunger forced us to stop for the only semi-decent food around, a buffet at Hong Kong Restaurant in Cloquet. I have never had "Chinese" food anywhere near that sweet. The Kung Pao chicken (annotated with a "(spicy)" warning) had not the slightest hint of spice, and tasted like a dessert. Even the filling in the cheese-filled wontons had to be at least 50% sugar. Anyway, dinner conversation about French politics was entertaining. Not only was I the only UMN person at the table, I was the only person from the US. There was a guy from Spain, the one female on the trip, from somewhere in southeast Asia, then a guy from France, one from South Korea, one from Switzerland, one from Hungary, and one from Azerbaijan. Also plenty of Italians and Dutch folk at the conference/trip, but not enough room at the table.
We then re-boarded the bus and got back to Minneapolis around 10:00. I've spent the rest of the weekend being completely bored, but at least I've only got 24 TNG episodes to go before I'm done with that. Also, my handy little 50th Anniversary PDG Particle Physics Booklet accompanied me to the center of the Earth, and I even went there with Keith Olive, one of the main guys in the Particle Data Group who put it together. He's one of our high energy theory guys at UMN, and the main guy who organized the mine trip and DSU itself. Definitely a worthwhile trip.
The CDMS professor I'm working for will be back from Kenya on Monday, so hopefully I'll get some very well-defined goals for this summer beyond the electronics glitch cut I've written already. I've just been looking at digitized triggers, so I still need to take a look at the raw data to do topological classications of the ionization/phonon pulses corresponding to the events that satisfy my cut and see if they're really glitches, but it looks good so far. Never thought I'd see typical χ2 values in the 10000 range. Weeow. So many degrees of freedom it hurts.
We got our hard hats and entered the descending cart in groups of about 10. The door locked, we went down a bit, a gate slammed over our heads, and we began the alarmingly fast drop to the bottom, half a mile down. There was a dim light in the cart, so I could see the rock wall flying past. Bumpy ride, very cramped, and it lasted about 3 minutes. The guide for the historical tour was too emotionally involved (his granfather died from mine-work at 41, his son's working in a mine now) and was mega-lecture-y, telling us how our pansy physicist problems/bad days can't compare to what they put up with. Still, the mine-cart train ride was very Temple of Doom-y and the climb up a tightly wound spiral staircase into an actual non-vetilated stope and the ensuing several minutes of talk in complete darkness was sort of neato.
After this, we split into 3 groups and toured various things on the lab side of the lowest level. Just outside the lab entrance there were dozens of bats on the walls and flying around. Several also have made it into the lab area and "dead bats in the detector" becomes a real concern. A geologist was doing funky simulations with gOcad to figure out what media specific neutrino events passed through based on the incoming angle (useful to MINOS), and also preliminary work for DUSEL, which is going to do some sort of study of archaea and bacteria underground, in the rock. They claim there's more biomass under the earth's surface than above it, for one thing. Clearly they're insane.
Next was the MINOS tour, a test for neutrino flavor oscillations, and something there's a possibility I'll work on in the next couple years. The giant mural was very impressive, as were the 460-something huge detector planes, set up with two computers per plane. Also, one of the computers in the electronics control room had 6 LCDs attached to it, which was completely ridiculous-looking. There were talks on the main injector and the near detector at Fermilab and how they managed to get all this huge equipment down the little mine shaft; we watched part of a DVD of lots of things being welded together. None of those detector planes touch the ground, by the way - the weight would possibly cause buckling, which would screw a lot of things up. They're all suspended from the ceiling by huge beams. Unfortunately, they only get a couple events per day, which is sort of boring. By contrast, CDMS is more exciting with a couple events per minute, and that's what we saw next.
I already sort of knew what the general experimental setup was, but I was still pretty impressed. They have a completely automated helium transfer process for the dilution refrigerator that keeps it at 40 mK for years at a time (an ADR like the ones I used in Madison can't be kept cold nearly that long - salt pills are wimpy). The actual detector assembly that holds the five towers was completely sealed off in a clean room you can barely see into, and everything was in general way more professional than I'm used to seeing, though all the heluim dewars and cryogenics equipment made it feel more like home. In the entire lab part of the bottom of the mine, air is curculated and kept at 72 degrees, water is easily accessible, and I think I'd be just fine doing a week-long shift there, "pressing the buttons," as I may do later this summer.
We returned in the shaft cart, just as quickly as we descended, then drove on the bus for 2 hours before hunger forced us to stop for the only semi-decent food around, a buffet at Hong Kong Restaurant in Cloquet. I have never had "Chinese" food anywhere near that sweet. The Kung Pao chicken (annotated with a "(spicy)" warning) had not the slightest hint of spice, and tasted like a dessert. Even the filling in the cheese-filled wontons had to be at least 50% sugar. Anyway, dinner conversation about French politics was entertaining. Not only was I the only UMN person at the table, I was the only person from the US. There was a guy from Spain, the one female on the trip, from somewhere in southeast Asia, then a guy from France, one from South Korea, one from Switzerland, one from Hungary, and one from Azerbaijan. Also plenty of Italians and Dutch folk at the conference/trip, but not enough room at the table.
We then re-boarded the bus and got back to Minneapolis around 10:00. I've spent the rest of the weekend being completely bored, but at least I've only got 24 TNG episodes to go before I'm done with that. Also, my handy little 50th Anniversary PDG Particle Physics Booklet accompanied me to the center of the Earth, and I even went there with Keith Olive, one of the main guys in the Particle Data Group who put it together. He's one of our high energy theory guys at UMN, and the main guy who organized the mine trip and DSU itself. Definitely a worthwhile trip.
The CDMS professor I'm working for will be back from Kenya on Monday, so hopefully I'll get some very well-defined goals for this summer beyond the electronics glitch cut I've written already. I've just been looking at digitized triggers, so I still need to take a look at the raw data to do topological classications of the ionization/phonon pulses corresponding to the events that satisfy my cut and see if they're really glitches, but it looks good so far. Never thought I'd see typical χ2 values in the 10000 range. Weeow. So many degrees of freedom it hurts.