Nate:

My guess is that we (ultimately) need better than ~1mm transverse alignment,
but I won't claim to know what we should call "zero" for purposes of
evaluating how close we are.  In particular, we know that the beam wants to
center itself order of a mm off the nominal beam alignment axis, and Jap's
polarization calculations indicate that is enough to be of some concern.
But right now, I don't know whether the "right" thing to do is reconfigure
the channel to put the beam where it "should" be, while putting the solenoid
on axis, or to accept where the beam wants to come out of the channel and
align the magnet to match that.

From your numbers, it looks like we may anticipate a tilt in the field of
order 1/2500 ~ 0.4 mrad.  This level of misalignment between the beam and B
field is not a problem {1-cos(theta)<10^-7}, but we do need to align the
detector package to the B field to slightly better than this level of
precision.  So this is the kind of tilt that shouldn't hurt us -- so long as
we know about and account for it properly.

Carl

+-----------------------------------------------------------------+
| Carl A. Gagliardi                                               |
| Cyclotron Institute              Phone:   (979)  845-1411       |
| Texas A&M University             FAX:     (979)  845-1899       |
| College Station, Texas  77843    E-mail:  cggroup@comp.tamu.edu |
+-----------------------------------------------------------------+

Created for the The Center for Subatomic Research E614 Project Projects Page.

Created by The CoCoBoard.