• aaa@lemmy.sdf.org
    link
    fedilink
    English
    arrow-up
    16
    ·
    3 months ago

    idiot here. can someone explain to me how come neutrons can’t penetrate concrete compared to lead.

    • ✺roguetrick✺@lemmy.world
      link
      fedilink
      English
      arrow-up
      11
      ·
      3 months ago

      Neutrons need something that provides them with lots of chances to have interactions. Water is good too. What blocks neutrons may not block gamma and vise versa. To block neutrons and high energy particles like cosmic rays that actually have mass to them you need something like a crash barrier.

    • jol@discuss.tchncs.de
      link
      fedilink
      English
      arrow-up
      4
      ·
      3 months ago

      Same. Aren’t neutrons capable of crossing the entire planet unless they directly colide with another particle?

      • Admetus@sopuli.xyz
        link
        fedilink
        English
        arrow-up
        29
        ·
        3 months ago

        I reckon you’re thinking of the neutrino which rarely interacts with matter.

      • Warl0k3@lemmy.world
        link
        fedilink
        English
        arrow-up
        14
        ·
        edit-2
        3 months ago

        I believe you’re thinking of neutrinos. Neutrons love bonking into things, and they’re really good at it. Too good; if the thing they’re bonking is too big they’ll just keep on bouncing, so you gotta bounce them off small stuff. Concrete has lots of small stuff bound up in it, so while there’s better shields (borax and paraffin slurry is a classic one) there’s few cheaper or easier to make shields than concrete.

    • HootinNHollerin@lemmy.world
      link
      fedilink
      English
      arrow-up
      3
      ·
      edit-2
      3 months ago

      If you throw a ball at a brick wall it will bounce. If you throw a ball into a ball pit it will be slowed down and stop