Re: colli cave question

[Richard Jones <richard.t.jones@uconn.edu>]

Jim,

This is certainly worth considering.  The main concern that I see right 
away is the real estate.  Right now the sequence following the first 
collimator is 50cm (sweep) + 200cm (iron) + 100cm (concrete) + 50cm 
(gaps) = 400cm.  The iron is there to stop muons from muon pair 
production in the primary collimator and from pion decays.  I think you 
still need the concrete in the forward direction to attenuate the 
forward neutron flux.  All of this could be simulated.

I suppose the permanent magnets are some ceramic material, right?  Any 
rare earths that might activate?

Richard Jones

Jim Stewart wrote:
> Hello Richard
>
> I was wondering if it would be reasonable to take one of the permanent
> magnet dipoles and use it as the first sweep magnet? The field is large
> with 1.5TM and we can put spacers in the gap to reduce the aperture to a
> 2cm hole. If you pack the whole thing in concrete then you still absorb
> neutrons.
>
>   -------------------------------
>   |                             |
>   |         concrete            |
>   |                             |
>   ------------------------------
>   |         | dipole |          |
>   |         |   o    |          |
>   |         |        |          |
>   -------------------------------
>   |                             |
>   |                             |
>   |                             |
>   -------------------------------
>
> Maybe you need a concrete block at the back.
>
> This may even have enough field to not need a second magnet.
>
>
> Advantages:
>    We have the magnet.
>    No active parts.
>    Nothing to fail.
>
>
> Dis-advantage
> The magnet is 4m long.
>
> Is this worth considering?
> Jim
>
>