[BTeam] [New Logentry] Supplemental LASO log

[Tom Oren]

Michele,

The version of ORFP that Arne refers to, rev 13b2, is still considered 
to be a draft and not the official released document. Mike Spata, the 
technical custodian for the document, is in the process of revising the 
document to identify new "official" knobs, but those are not yet known. 
The draft contains the present best known information, but Mike did not 
want to release this to Ops, choosing instead to circulate the draft 
among the LASOs for their use only. This seems appropriate as we are 
operating in an "Expert-only" tuning mode, and the LASOs who are doing 
the tuning should all have electronic copies of this draft document from 
Mike.

So please continue to point to the released version of the document, 
rev. 12, on JTabs.

Thanks,
Tom



On 3/28/2014 4:12 PM, Michele Joyce wrote:
> Has this version of ORFP actually been released? Should I use the DRAFT
> version for JTABS?
>
> On 03/28/2014 03:40 PM, freyberg at jlab.org wrote:
>>
>>
>>   Supplemental LASO log <https://logbooks.jlab.org/entry/3277931>
>>
>> Lognumber 3277931 <https://logbooks.jlab.org/entry/3277931>. Submitted
>> by freyberg <https://logbooks.jlab.org/user/freyberg> on Fri,
>> 03/28/2014 - 15:37.
>>
>> Logbooks: 	BTLOG <https://logbooks.jlab.org/book/btlog>
>> Attached Files: 	
>> Latest ORFP procedure
>> <imap://erb@mail.jlab.org:993/fetch%3EUID%3E/INBOX%3E144068?header=quotebody&part=1.1.2.3&filename=optics_restore_proc_13b2.pdf>
>>
>> Arrived this morning to relieve Tiefenback and Yves who worked over
>> night to establish a sound setup. They had a good steup through
>> pass-2, but were stuck at that point due momentum instability. Upon
>> arrival they were in the middle of dealing with this periodic energy
>> changes when I arrived and the source proved difficult to identify.
>> The RF-power guru's arrived at 7am and identified a railed cavity
>> 1L02-2 that had no phase control. With this repaired dispersion/CS
>> tuning resumed and progress in completely pass-3 by noon was almost
>> accomplished.
>>
>> I benefited greatly from the work of Yves and Mike (and all the rest
>> who have gotten us to this point), specifically they identified that
>> *too strong* of an RF kick during dispersion minimization. To get the
>> required kicks, they instructed me to only use *1* RF cavity during
>> fOpt and 30Hz. This tended to yield consistent results between fOtp
>> and real-time 30Hz, which was very comforting to me.
>>
>> At one point in the process, an old veriosn of ORFP made its way into
>> my hands and some time was lost working with the *wrong knobs*! Please
>> make sure you are working from Rev. 13b2 of ORFP (attached). Do not
>> use an older version, do not rely on the color coding of the screens.
>>
>> Even with the correct knobs, I found it very challenging to get the CS
>> match into Arc6. Dispersion suppression went smoothly, but there was
>> no traction on CS X or Y with the nominal knobs. I then made the
>> decision to move forward without a CS match into Arc6, reasoning a
>> mis-match in Arc6 is after the fact. I am wiling to entertain
>> arguments as to why this is the worst decision in the history of 12GeV
>> CEBAF.
>>
>> We then move to the Hall-A dumplette, we found the line was in a
>> totally mis-configured state, supplies off, magnets off-loop, magnets
>> mis-configured. We steered up the line, put LAM1C on design. Minimized
>> steerers as best as possible. And started a documentation effort,
>> all-saves, viewer tour, aperature check.
>> At the time of this writing, an aperture check to the Hall-A dumplete
>> is in progress. Lots of transverse aperture, energy aperature data is
>> being collected now.
>>
>> Several times this afternoon, trucks travelling down the South Linac
>> trip off the C100s in the South very frustrating. but for the most
>> part the Accelerator has been up more than it has been down!!!! This
>> has been absolutely crucial to making progress.
>>
>> At 3pm I met with the Hall-A users. The tentative plan is to continue
>> our effort, if we can re-establish beam to Hall-A by midnight, they
>> have a program that can use less than 10microAmperes over night.
>> Saturday, if we are in a position to support it, we will see how high
>> we can go with CW. Sunday Owl, Hall-A will be back to low beam
>> current. Sunday day the Hall would like to do Moeller, so in the
>> morning the LASO (Joe Grames) will assist/lead setting the Wien Filter
>> and after that the hall will start the Moller program. This means Yves
>> will have to come in well before his nominal Swing Supplemental Shift.
>> I hope we will be in a position to not need Supplemental LASO on
>> Sunday Swing, if not I need a volunteer.
>>
>>
>>
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