More to Check

On 2017-03-29 9:05 AM, Cynthia Keppel wrote:
Hi Juliette,

Here's one more PREX2/CREX magnet thing to check, hopefullly already 
on your list. But, just in case not. the septum fringe fields will 
have some impact on the new resistive quad field clamps, which are 
pretty thin at the edges. We are mitigating this for APEX by adding 
Iron, but their case is different. I think that it will be likely worse 
for PREX2/CREX I mentioned this to Robin briefly, and she agreed that 
it could be a problem. You can check in with her to discuss what to 
look for if that's helpful; I've cc'd her here.

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Today, Thia visited me and said that she and Rolf question whether 
we need vacuum coupling between the target and the HRS.  I replied 
that it's needed for momentum resolution to separate inelastics, 
and she said they had estimated that it would not matter, and that 
eliminating this would simplify the design, reduce cost, and reduce 
the time for fabrication and installation.  I suggested that what 
would help is a plot showing the background contamination and the 
implied systematic error for PREX and CREX, both with and without 
the vacuum coupling, to prove that vacuum coupling is necessary.  
She agreed that would help.

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We were told that our radiation calculations will need to be benchmarked
and validated against a standardized benchmark to be defined by RadCon.
This is a new requirement of all Monte Carlo efforts.  The idea is that
RadCon has no time to check each MC, but they can challenge us to reproduce
certain calculations to verify that our model is good.
However, as of this date (Apr 11, 2017) I have not seen that defined yet.

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Roger Carlini seems to be worried (and I'm not 100% sure I'm capturing this
correctly) that there will be a lot of heat and radiation dumped into our
plastic radiation shielding, turning it to dust and making if fall apart,
and possibly heating it up to the point of catching on fire.  Well, we don't
want that.  On the other hand, maybe we are orders of magnitude away from
such a danger ?  It should be addressed.