sPHENIX discussion of the superconducting solenoid

["Yip, Kin" <kinyip AT bnl.gov>]

-------- Original message --------

From: John Haggerty <haggerty AT bnl.gov>

Date: 2/17/22 15:12 (GMT-05:00)

To: "Meng, Wuzheng" <meng AT bnl.gov>

Cc: "Yip, Kin" <kinyip AT bnl.gov>

Subject: Re: moving one of the doors by 1 inch

Kin and Wuzheng,

Just so you know your work is important and timely, if you go to the end
of this album:

https://photos.app.goo.gl/QfhZh6iK9C1DHb7J9

you'll see two of the doors delivered to building 912 today.  (These are
the flatest of the doors).

Thanks again for your work and insights.

On 2022-02-14 11:31, Meng, Wuzheng wrote:
> John,
> Thank you so much for your kind words.
> In our previous studies, such as the thickness of the pole tips, we
> have learnt that they are not sensitive to the central fields. As far
> as I understand, this is because the pole-pieces are located much
> farther than that in the BaBar magnet, although both are using the
> same SC coil. In sphenix magnet, only small portion of flux lines
> reaching the pole face; most flux lines are attracted and circulated
> by the side steel (HCal). Therefore, small distortions of pole-piece
> gave very small affect in the TPC region, which is ~200 cm away.
> Actually, one inch is not small; it is 12.5% of the thickness (8
> inch).
> However, in order to prevent large cumulating errors, we do not want
> people to feel that tolerances are not important at all. Specifying
> proper tolerance is engineers' job.  They play crucial roles during
> the production and installation.
> Please comment.
> Wuzheng
>
> -----Original Message-----
> From: John Haggerty <haggerty AT bnl.gov>
> Sent: Monday, February 14, 2022 10:39 AM
> To: Hock, Jonathan <jhock AT bnl.gov>
> Cc: Yip, Kin <kinyip AT bnl.gov>; Meng, Wuzheng <meng AT bnl.gov>; Mills,
> James A <mills AT bnl.gov>
> Subject: Re: moving one of the doors by 1 inch
>
> Jon,
>
> So as you saw, Kin and Wuzheng jumped right on this question and
> generated a "worst case" map over the weekend.  I looked at it, and as
> far as I can see, the changes in to the field are not going to have
> any serious repercussions, so we can continue the work at Strecks.
>
> Thanks again to Wuzheng and Kin for helping out on this so
> expeditiously.

---
John Haggerty
haggerty AT bnl.gov
cell: 631 741 3358