[BTeam] Injector Alignment

[Michael Tiefenback]

Jay,

I do not read your comments as arguing that we ought _not_ to move the cryounit.  I am not certain whether you think an attempt to "improve" things is ill- or well-advised, or whether you are attempting to withhold opinion on that.

The (large) beam offset in the beam line downstream from the cryounit has been a problem from multiple perspectives, and I thought we should consider what might be done.  The 1.2 mm offset mentioned in Reza's note (survey reference) that Todd forwarded appeared to me implicitly to portray a 1.2 mm offset as the total content related to the beam line issue.  I think this is a significant integer factor too small (like five times too small), and that speaking "1.2 mm" in this context is very misleading to observers unfamiliar with the actual situation.

Michael Tiefenback

________________________________
From: Jay Benesch <benesch at jlab.org>
Sent: Friday, October 2, 2020 12:47
To: Michael Tiefenback <tiefen at jlab.org>; bteam at jlab.org <bteam at jlab.org>
Subject: Re: [BTeam] Injector Alignment

Mike,

The transverse kick is why we never use MQJ0L01: add the feeddown to the
transverse momentum and the correctors are too feeble.  Steer to center
the beam before 0L02 and one can get by.  The peak beam envelope is
large (~2.5 mm sigma) as one develops the FODO lattice through
0L02/0L02A, 0L03A/0L03, 0L04.  That's why I wanted to switch to solenoid
focusing in the 6 MeV region.

Jay
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