Avoid accidents with superconductive magnets in LHC.

|
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
 4 views
of 9

Please download to get full document.

View again

Description
Avoid accidents with superconductive magnets in LHC. What if protons collide with the magnets?. An important diagram. Only under the 2  dimensional surface in a 3 dimensional space the material used for the wires of the magnets, niobium-titanium, is superconductive
Share
Transcript
Avoid accidents with superconductive magnets in LHC.What if protons collide with the magnets?An important diagram
  • Only under the 2  dimensional surface in a 3 dimensional space the material used for the wires of the magnets, niobium-titanium, is superconductive
  • This surface is determined by temperature, magnetic induction and current density.
  • CERN HST 2001An important diagram(2)
  • To be save it is necessary to stay far from the surface, it limits current densities, magnetic induction and temperature.
  • In LHC B must be some 9 T, current some 13 000 A, so a temperature below 2 K is needed for safety reasons
  • CERN HST 2001What happens if a proton hits the magnet?
  • Sometimes a proton could hit de side of the tube, hitting a superconducting magnet
  • The collision point heats up
  • This spot is no longer superconductive
  • CERN HST 2001This means on the diagram
  • If the temperature of the spot rises higher than 5 K, Niobium-titanium no longer is superconductive.
  • CERN HST 2001Catastrophy?
  • Heat due to Ohm’s law is generated
  • This causes the non-superconductive spot to become larger quickly, and more heat is generated
  • Etc...
  • The experiment breaks down
  • CERN HST 2001Unless...
  • The heat of the initial collision spot is taken away.
  • Superfluid helium takes care of that:
  • it flows all over, the magnets swim in this fluid
  • the heat capacity of helium becomes larger with lower temperatures, one of the reasons why the temperature is so low
  • CERN HST 2001As a consequence
  • The helium must flow constantly and cool permanently, taking the heat of accidental collisions away
  • The circuit should continuously be able to cool all helium to this low temperature
  • They will need 5000 tons of helium in this giant magnet, the production of the whole world during one year
  • CERN HST 2001If this is not enough
  • The beam must be taken out of the tubes
  • A kicker magnet kicks the 2850 bunches of protons into a larger magnetic field, allowing the protons to bend into a pipeline of 100m long.
  • Another magnet disperses the proton bunches to bigger surfaces to collide with, the energy is absorbed by special materials (mainly graphite) at the end of the tunnel
  • CERN HST 2001
    Related Search
    We Need Your Support
    Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

    Thanks to everyone for your continued support.

    No, Thanks
    SAVE OUR EARTH

    We need your sign to support Project to invent "SMART AND CONTROLLABLE REFLECTIVE BALLOONS" to cover the Sun and Save Our Earth.

    More details...

    Sign Now!

    We are very appreciated for your Prompt Action!

    x