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Science

800,000 Tons of Rock Excavated for Massive Underground Neutrino Detector (energy.gov) 77

Posted by EditorDavid from the particles-of-confederation dept.
800,000 tons of rock have been excavated from a South Dakota research facility — part of a multi-year process "to help answer some of physics' biggest questions," writes America's Energy Department.

"The caverns they excavated will hold a massive particle detector and accompanying equipment." Along with partners from more than 35 countries, the Department of Energy's Office of Science is supporting the Deep Underground Neutrino Experiment at the Long-Baseline Neutrino Facility (LBNF-DUNE)... To study how neutrinos change type as they travel, LBNF-DUNE will be sending a stream of neutrinos from DOE's Fermilab National Accelerator Laboratory in Illinois [nearly 600 miles away] to South Dakota. At the beginning and end of the particles' journey, detectors will measure the types of neutrinos and antineutrinos. By comparing the rates of how both particles change type, scientists may find a difference that accounts for that ancient misalignment.
There's also hope they'll detect neutrinos from supernovae explosions — and maybe even decaying protons LBNF-DUNE will use massive, seven-story tall detectors. Each detector will have 17,000 tons of liquid argon. That vast quantity of liquid maximizes the likelihood that scientists will detect as many neutrinos as possible. The far detector — the one in South Dakota — will be located about a mile underground. That distance places it in the right location compared to Fermilab and blocks the detector from other cosmic particles.
"Just carrying out the excavation took three years," the announcement notes. ("The team had to dissemble the equipment, move it deep underground, and then reassemble it.) The 800,000 tons of rock were moved to the surface and then stored in a former mine.

"Now that the excavation is complete, the LBNF-DUNE team is moving on to the next steps. Currently, they are installing the far detector in the Sanford Underground Research Facility. They anticipate finishing construction and starting to operate the detector in 2028. The team will then move on to installing the near detector at Fermilab.

"The launch of LBNF/DUNE will be the beginning of a new era in understanding neutrinos and knowing more about our universe as a whole."

800,000 Tons of Rock Excavated for Massive Underground Neutrino Detector More | Reply

800,000 Tons of Rock Excavated for Massive Underground Neutrino Detector

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  • I glanced over TFA and I couldn't confirm this but; any reasons they didn't use dynamite?

    Tunnels through rock usually use that method. It's been used for railway tunnels etc. for ages.

    Even in a city where I lived, they used dynamite to clear the rock under a street to install new water and sewer bigger pipes deeper than the old ones although in another city with the same use case, I have been told dynamiting was forbidden by that city in their case so it took them ages compared to the other city.

    Anyway, may

    • I glanced over TFA and I couldn't confirm this but; any reasons they didn't use dynamite?

      Tunnels through rock usually use that method. It's been used for railway tunnels etc. for ages.

      Even in a city where I lived, they used dynamite to clear the rock under a street to install new water and sewer bigger pipes deeper than the old ones although in another city with the same use case, I have been told dynamiting was forbidden by that city in their case so it took them ages compared to the other city.

      Anyway, maybe it would have taken less time than 3 years using dynamite if indeed they didn't use any and I assume they are far from any city.

      Or, maybe they did use dynamite but don't mention to sound somehow more politically correct. My inquiring mind is curious...

      There is a link in TFA to an article about the construction https://news.fnal.gov/2021/05/... [fnal.gov] It doesn't mention dynamite as such but "blasting".

    • For doing tunnels that are long and uniform, blasting comes out as more expensive and takes longer to do.
      Blasting can be done for a small area and with little setup.
      https://bestsupportunderground... [bestsuppor...ground.com]

      • For doing tunnels that are long and uniform, blasting comes out as more expensive and takes longer to do. Blasting can be done for a small area and with little setup. https://bestsupportunderground... [bestsuppor...ground.com]

        I concur. The old abandoned Rail tunnels in our are were done Dig and Blast. They definitely aren't uniform. Especially when they had to clear out the fractured rock that wasn't obvious immediately after blasting.

  • It hadn't occurred to me that neutrinos could be generated with a preferred direction. Would someone care to explain how it is done?
    I asked Gemini and I post excerpts form its replies. I'm confident enough to reject one but I don't know about the other
    - How can one send a stream of neutrinos?
    -- "By colliding high-energy particles (like protons or electrons) in a particle accelerator, neutrinos can be produced as a byproduct. These neutrinos can then be directed using magnetic fields, but controlling t

    • Re:How is a stream of neutrinos generated? (Score:5, Informative)

      by necro81 ( 917438 ) on Monday October 07, 2024 @08:26AM (#64845309) Journal

      It hadn't occurred to me that neutrinos could be generated with a preferred direction.

      You cannot steer a beam of neutrinos using magnetic fields - they are neutral particles. What you can do is generate and steer a beam of more easily-controlled particles - particles that readily decay into neutrinos.

      This page from Fermilab [fnal.gov] describes the process. They start with a high-energy proton beam going in roughly the right direction. The proton beam hits a graphite target, creating a spray of collision products. You can tune the beam energy to favor certain collision products over others. In particular, they want to maximize the production of positive pions. These particles decay rapidly, but they do stick around long enough that you can (with magnetic fields) separate them from the other chaff, select for pions that have a certain momentum, and focus the beam in the direction you want. Not long after, the pions decay into anti-muons and neutrinos - still mostly going in the same direction the pion beam was going. (They can also change the pion filter to select for negative pions to produce antineutrinos.) The muons get absorbed by a thick wall of steel and concrete, but the neutrinos just sail on their way.

      The resulting neutrino beam is not perfectly focused - think spotlight rather than laser - but has enough flux going in the right direction for the experiment to work.

    • These responses are a great example of why LLMs are absolutely godawful for producing factual information, because both are massively inaccurate or just plain wrong. 1) To produce neutrinos you use protons, not electrons (it might technically be possible to use electrons, idk I'm not that kind of physicist, but no one does). 2) you don't smash them together, you hit them against a target. 3) Neutrinos are neutral particles and can't be guided using electromagnetic fields. 4) Momentum conservation means the
  • Stop neutrino change now!
  • And what do they hope accomplish ? What's the goal ? Teleport ?? Time travel ? Warp drive ? Create warp hole ? Better microwave oven ? Death ray ?? Figure out how aliens travel in their space crafts ???

    • Re: (Score:2, Funny)

      by Errol backfiring ( 1280012 )
      <irony> They want to build a large shelter to hide in when right-wing nut jobs take control. The description should keep them away, as these people are also very wary of science. </irony>

    • Re:To study how neutrinos change type as they trav (Score:5, Informative)

      by necro81 ( 917438 ) on Monday October 07, 2024 @08:39AM (#64845323) Journal
      There are a couple of things this research should shed light on.

      Neutrino oscillation is itself a weird phenomenon. It was predicted as a theoretical possibility decades ago, but like all things related to neutrinos really, really hard to detect. We don't have a good explanation for why it should be possible (other than: it's not forbidden by our models). This experiment should help pin down the what and how of that mechanism.

      The second main thrust is that this experiment can produce neutrinos and antineutrinos (not at the same time, but they can switch back and forth). That hasn't been possible before (we've mostly been detecting neutrinos from the sun or cosmic rays, and we have to take what we can get). Our present understanding of physics predicts that matter and antimatter should have existed in exactly equal amounts during the Big Bang. It obviously didn't, because we and the whole cosmos exist, with no antimatter to be found. It is possible that better understanding neutrinos is the key to explaining that mystery.

      A third goal is to train and employ a new generation of particle physicists, highly-skilled technicians, computer scientists, and other really intelligent people. That by itself probably doesn't mean much, except 1) it avoids a brain drain to other countries, while 2) attracting such talent to the US, and 3) such people don't necessarily stay at accelerator labs forever: they go out into the world and use their impressive skills for other things that we all benefit from.

      • The second main thrust is that this experiment can produce neutrinos and antineutrinos (not at the same time, but they can switch back and forth). That hasn't been possible before (we've mostly been detecting neutrinos from the sun or cosmic rays, and we have to take what we can get).

        That's not correct: not counting the short baseline neutrino beams that discovered the muon and tau neutrinos, this long baseline design has been done before. T2K ("Tokai to Kamioka") in Japan and CERN-Gran Sasso are both examples of this long baseline neutrino beams and even Fermilab has sent beams to the Soudan mine in Minnesota before. DUNE is improving on these with a greater beam power (so more neutrinos) and a longer baseline of over 1,000km vs. several hundred for T2K. These improvements should give

    • And what do they hope accomplish ?

      To answer known questions in science? There is no grand conspiracy here.

      What's the goal ?

      To answer known questions in science.

      Teleport ?? Time travel ? Warp drive ? Create warp hole ? Better microwave oven ? Death ray ?? Figure out how aliens travel in their space crafts ???

      Understanding a fundamental particle of physics may yield results that no knows yet.

  • We already know they exist. We already have detectors. All I see is vague statements about the future and our understanding and blah blah blah. This is not a cheap project. What are we going to learn from it other than "yep, they still exist and we can still detect them sometimes."

    • We already know they exist. To study how neutrinos change type as they travel,

      The purpose of this detector is not merely to detect neutrinos exist. The purpose is to determine how neutrinos oscillate. It is like the 2nd sentence of the quoted article: "To study how neutrinos change type as they travel, . . ."

      All I see is vague statements about the future and our understanding and blah blah blah.

      We do not know how neutrinos oscillate. Neutrinos are an elementary particle for which there is little known. This will expand knowledge on them.

      This is not a cheap project.

      And?

      What are we going to learn from it other than "yep, they still exist and we can still detect them sometimes."

      How about how they oscillate? How about using that oscillation to detect other phenomenon? We do not know the ramifications of su

  • The time needed to detect particles... (Score:3)

    by LordHighExecutioner ( 4245243 ) on Monday October 07, 2024 @08:46AM (#64845339)
    ...is inversely proportional to the amenity of the place where the detector is located.

    Years ago two experiments were performed to detect an exotic particle. One detector was at about 4,000 meters depth in the Hawaii offshore, the other deep under a mountain. The Hawaii experiment needed three times the time that people in the cave needed to have the detector up and working, and find the particle they were looking for.

  • Wait - 3 years, to dig out 800,000 tons of rock, drag it up, and then store it down a mine...?

    I would have just used the mine. :)

    • Sure if the mine was suitable but I have a feeling that a mine dug out to follow veins of material was not suitable for a scientific experiment.
  • So they dug out rock and dumped it in an old mine. Any normal sane person would simply have used the old mine for the detector.

    • Re: (Score:2)

      by GoTeam ( 5042081 )

      So they dug out rock and dumped it in an old mine. Any normal sane person would simply have used the old mine for the detector.

      Maybe there were bats living in the old mine? Everyone loves bats!

    • So the mine has the uniform shape and rock thickness for these experiments? The mine was not built with winding passages because it was following veins of material? Any and all equipment needed will fit in the old mine's tunnels? Basically your premise is every hole in the Earth is the same.
  • Goddam string and particle physicists are costing USA a bundle and delivering squat! We need to defund these guys until they're limited to a handful of pencils and paper pads.

    Texas' contribution to taxpayer fundwasting: the superconducting supercollider (1/8 of it): https://www.dallasnews.com/new... [dallasnews.com]

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