[Bteam] BTeam notes: Tue 24 Jan 2012

Matt Poelker poelker at jlab.org
Thu Jan 26 09:27:24 EST 2012


During the long shutdown, John Hansknecht will try to implement an idea 
that will allow us to produce longer laser pulses, which as Mike T 
points out, could improve transmission, reduce prebuncher gradient, and 
eliminate tails, etc.,.  Unfortunately, a longer laser pulse will not be 
available during QWeak and the rest of the 6GeV run.
Matt


Todd Satogata wrote:
> Bteamers,
>
> Here are the notes from yesterday's weekly meeting. There was a lot of 
> discussion about the
> tune time on Thursday that attempted to install a new M56 optics in 
> the injection chicane
> but eventually was removed. Some issues were found in the model that 
> will be addressed,
> a LEMI configuration problem was fixed, some optics anomalies (such as the
> disappearing/reappearing blown dispersion mismatch out of arc 2) need 
> understanding.
> We learned important things during that tune time, but we will be more 
> efficient if we
> have more time to plan and double-check for tuning; Yves's summary at 
> the end of what
> worked and what didn't will be helpful for the planning of the 5-pass 
> spin-up; a plan is
> being developed that will be discussed and hopefully scheduled by this 
> week's beam
> studies scheduling meeting on Friday.
>
> Alex Bogacz has graciously agreed to chair the BTeam meeting while I'm 
> on travel
> to SLAC Jan 26-Feb 1 inclusive.
>
> -Todd
>
>
>   BTeam-2012-01-24
>
>
>     1 Optics on Call Report/Schedule
>
>     * Rotates at BTeam (10:00 Tuesdays)
>     * Medium-term machine development
>           o DONE Write 5-pass spin-up ATLis (Jay, a11894
>             <https://cebaf.jlab.org/atlis/task/11894>), relies on ARC9
>             box supply repair (ongoing)
>     * 17 Jan-24 Jan: Vasily/Yves (Outgoing)
>           o SL has still been running few degrees off crest to reduce
>             Compton backgrounds (Jay)
>           o Hall B sensitivity to energy drift of some concern (Tief)
>           o Mon 23 Jan Add M56 optics in injector (Yves/Jay, a11924
>             <https://cebaf.jlab.org/atlis/task/11924>)
>                 + Not successful, see Yves's entry at e1661381
>                   <https://cebaf.jlab.org/elog/entry/1661381>
>                 + HGAP for inj chicane dipoles will be updated; 0L/0R
>                   optics plan in the works
>                 + 12h of tuning time: what was gained? How are we
>                   accountable for that time?
>                       # Who owns the process of unscheduled tuning?
>                         Optics or plan owner should be focus; PD
>                         schedules time
>                       # Scheduling for studies <1h later makes things
>                         rushed, perhaps hours of inefficiency
>                       # OptiM to elegant translation can use better
>                         efficiency (at least yesterday)
>                       # High sensitivity of Compton halo to 1L02 quad
>                         was found at end in current configuration
>                       # Now running 2.5 degrees off crest in SL,
>                         better than the 6+ degrees over weekend
>                       # We're very likely on the edge of something,
>                         including scraping, based on large sensitivities
>                       # RayTrace would provide optics, may also well
>                         provide an aperture check (Tief)
>                       # Spot was a lot tighter in 1A with the M56
>                         improvement, so we will likely want to use
>                         this in Feb
>                       # Is a longer laser pulse feasible for 180uA for
>                         better injector transmission/Hall B? (Tief)
>                       # Alex: Can redesign an M56 optics with a
>                         stronger 1L02 quad setting for potentially
>                         improved stability
>                       # Underlying cause of arc2 dispersion match
>                         blown? Was seen in previous week as well
>                         (Jay/Spata/Tief)
>                       # DONE Jay has changed LEM config file for NL to
>                         set 1L02 quad to 521.6 (as of AM Jan 24 2012)
>                       # TODO injector rematch with HGAP in 0R dipoles
>                         (Michele/Yves, report Feb 02 BTeam)
>                       # TODO Address blown arc2 dispersion match
>                         during Jan 25 beam studies recovery (Optics)
>                       # TODO Planning group for M56:
>                         Yves/Jay/Tief/Alicia/Alex/Ed/Geoff/Yuhong
>     * 24 Jan-31 Jan: Ed/Alex (Oncoming)
>           o TODO Readdress injection matching to NL, SL gang phase,
>             Hall C Compton
>           o TODO Restore SL MOMOD after SL on crest, confirm good Hall
>             C Compton rates (Tief/ops)
>           o TODO Diagnose intermittent problems in NL MOMOD (Musson?
>             Tief? Plawski?)
>     * 31 Jan-07 Feb: Yuhong/Geoff
>           o 5-pass spin-up schedule? Mid-February for Hall A, but
>             early Feb for Hall B shift?
>     * 07 Feb-14 Feb: Balsa/Todd
>     * 14 Feb-21 Feb: Fanglei/Mike Spata
>     * 21 Feb-28 Feb: Todd/Jay
>
>
>     2 Measuring Bunch Length using 1A Sync Light Monitor (Tief)
>
>     * New BTeam elog entry on this procedure: e1661304
>       <https://cebaf.jlab.org/elog/entry/1661304>
>     * Done capturing images from datacube; online bunch length
>       application may be resurrected (Michele/Tief)
>     * Arne believes this will be resurrected when we have pure digital
>       cameras for 12 GeV
>     * TODO Prioritize and projectize for long down (Arne)
>
>
>     3 C100 Status
>
>     * 26/52/79 Hz signal on 1/4 cryo drive gradient/phase (Suleiman/Spata)
>     * Beam studies rescheduled for Wed 25 Feb
>
>
>     4 Beam Studies Report 18 Jan 2012
>
>     * Studies scheduled 08:00-20:00 (on time)
>           o a11858 <https://cebaf.jlab.org/atlis/task/11858> 0.0 C100:
>             Search for 79 Hz (Parisitic, Suleiman/Spata; strong 52 Hz
>             on 1/4 cryo drive gradient/phase)
>           o No other studies accomplished due to box supply failures,
>             repair
>
>
>     5 Beam Studies Scheduled 25 Jan 2012
>
>     * TODO Submit ATLis items for desired beam studies for next week
>       (25 Jan)
>     * Same studies as last week based on lost time to box supply failures
>     * Studies scheduled 08:30-20:30
>           o *[X]* ------ 1.0 Optics: Fopts/allsaves
>           o *[X]* a11882 <https://cebaf.jlab.org/atlis/task/11882> 8.0
>             C100: Stability testing (Hovater, Spata, etc, full
>             gradient on both C100s, 10uA)
>           o *[X]* a11865 <https://cebaf.jlab.org/atlis/task/11865> 1.0
>             Modeling: RayTrace validation (Bodenstein, Tief)
>           o *[X]* a11885 <https://cebaf.jlab.org/atlis/task/11885> 0.0
>             PePPo: Modeling (Grames, Contingency)
>           o *[X]* a11849 <https://cebaf.jlab.org/atlis/task/11849> 0.0
>             Mott: Mott DAQ Test (Suleiman, Contingency)
>           o *[X]* ------ 2.0 Optics: Restoration
>     * TODO Optics should write notes, observations of fopt/etc to
>       Bteam elog
>           o Include pathlength check (pathlength was good Mon day)
>
>
>     6 Next week
>
>     * Alex Bogacz has graciously agreed to chair while Todd is on travel
>     * Hall B to 5th pass ~ Feb 1?
>
>
>     7 From last week: Evaluate possibilities of Krest during beam
>     restoration (Okay)
>
>     * Takes more like 4h to run through both linacs to get decent
>       results (Terry)
>     * But Hall C doesn't get good data while Krest is running either
>       (but Hall B can)
>     * Perhaps part of 2h can be a manual touch-up of cresting (15 min
>       total, 2 operators)
>           o TODO Todd has emailed Noel to see if manual touch-up is
>             acceptable weekly retune
>
> ------------------------------------------------------------------------
>
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-- 
Matt Poelker
Jefferson Lab
MS Bldg 5A, Rm 500-17 
12000 Jefferson Ave., 
Newport News, VA 23606
poelker at jlab.org
757-269-7357 office
757-897-9408 cell

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