sPHENIX discussion of the superconducting solenoid

[Kin Yip <kinyip AT bnl.gov>]

Hi John and Achim,

I used my usual MCNPX energy deposit simulation to do something quick (worst scenario). 

From the BaBar paper （like this one) :
https://collab.external.bnl.gov/sites/sPHENIX-Magnet/Shared%20Documents/BaBar%20Documents/The%20BaBar%20Superconducting%20Coil;%20Design,%20Construction%20and%20Test.pdf

I made up a rectangle of 1.4 mm x 6.4 mm of copper (I didn't bother with NbTi) surrounded by the Al   8.4 mm x 20 mm.

Then, I hit proton directly on it (with some beam sigma if 0.28 cm  --- something that I used for the calculation in RHIC).   Quickly, I get the total energy deposit as such :

2.249 MeV/g per  proton  (hitting it) on the copper   and
1.18   MeV/g per proton                    on the Al stabilizer,

which are

3.6E-13 J/g per proton   and
1.9E-13 J/g per proton.


Our proton beam is said to have a max. of 2.5E13 (totaled from all 110 bunches).   I'm not sure who can make the beam turn 90 deg. and hit the Magnet.   But let's say that it's possible
that all the beams were dumped in one spot of the Magnet coil, the total energies are

~9.0 J/g  (Cu)  and  4.7 J/g (Al-stabilizer) .

From the Enthalpy curve (eg. Fig 3 on p.5) :
https://collab.external.bnl.gov/sites/sPHENIX-Magnet/Shared%20Documents/Miscellaneous%20(General%20Knowledge)/Material%20Properties%20at%20Low%20Temperature.pdf

or some others that Bob Lambiase showed me,

the temperature rise would be < 100K.    So, it'd probably quench the magnet but it won't burn a hole.  

If George or somebody asked this kind of question again in future review, I would answer with the above.   Please let me know if you somebody find something critically wrong.

Kin