In close contact with Claude we have put the
design of the small magent around the TPC-vessel
so far that I feel confident in giving it in the
workshop here. Infact, I had a long discussion with the
boss of machining here two days ago and he seemed quite
confident and intersted in doing the work. I just have
to supply the tubing.

The hole magnet fits easily between the flanges of the
TPC-vessel.

We think we can mount the small magnet without drilling out
(enlarging) any screwholes in the vessel-flange, we are using
4 holes separated by 90 degrees to feed through the 4 tubes
(2 times water/current in/out). So Claude feels much better
about it.

I am still investigating the water-connections outside,
but it looks like we have found a usable fitting.

Concerning the tubing we are going to use the round one
for the inner magnet because of 2 reasons:
1) The square one does not fit through the holes and it
would be hard to braze a round to a square tube accoring
to the engineer here.
2) The scattering induced by the square tubing do to its
larger mass is a factor of 4 larger for the same number of
windings. Equal scattering (3 windings only)  pushes the
magnet current up to 500 A and makes the cooling harder again.


Attached I send 4 drawings showing parts of the magnet.
The hard thing is to get the 2 tubes of one coil through the
TPC screw holes. But we think that as one can bend the
copper tubing easily a few degrees, this is possible.

The length of the tubing outside the flange to the
water-connector should be longer than ePC1 + pre-amp cards.

Large magnet option: We thought independent of the small
magnet solution the large magnet is a future option which
migth be used with a possible different vessel material.

Best regards
Bernhard