[Bteam] hall C halo and tail

[Arne Freyberger]

Jay and bteam:

    Bteam or at least a core set:  Optics-on-call, Injector-On-call, B & 
C Beamline physicists, EES core (Mounts/Lauze) should meet Tuesday after 
the 8am to discuss the path forward on establishing a robust 180uA 
setup.     There are many issues that need to be dealt with so please  
read the elog and perform any parasitic (archiver) investigations  ahead 
of time so that we have an efficient meeting.

Arne



On 01/15/2012 01:33 PM, Jay Benesch wrote:
> Mike Tiefenback has a long entry about the errors of our (Ops) ways in
> dealing with bunch formation imperfections by running the SL 1.6 degrees
> off crest to get Compton scintillator rates down.
>
> http://opweb.acc.jlab.org/CSUEApps/elog02/elog_item.php?elog_id=1659323
>
> Dispersion was checked in the C line and adjusted in the vertical plane;
> horizontal was fine.
>
> Brandi has an annotated elog showing some of the investigation this
> morning.
> http://opweb.acc.jlab.org/CSUEApps/elog02/elog_item.php?elog_id=1659650
>
> Clyde elogs about a slow quarter CM anomaly that's been present since
> the 6MSD.  It wasn't there before the 6MSD.
> http://opweb.acc.jlab.org/CSUEApps/elog02/elog_item.php?elog_id=1659647
>
> Terry Carlino suggested taking the NL off crest instead of the SL so the
> BLM activity in arc 1 would also be reduced.  Suggestion was made after
> everything was stable, so we didn't.
>
> I suggested to Terry, and now suggest to the B team, that we go back to
> finite M56 in the injector chicane to compress the bunch for the rest of
> the 6 GeV era.  We know there's a problem in one or both of the injector
> CMs.  We know that we're not going to get sufficient fast diagnostics to
> find it before the beam shuts down.  We know that 0L04 CM is going to be
> replaced with a "C100" and new LLRF controls.  Let's inelegantly solve
> the problem for the rest of the run.
>
> Discuss Tuesday?
>
> Jay
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