[BTeam] no bteam today.

[Michael Tiefenback]

Camille discovered she is (still) not on the "allowed senders for bteam" list, and asked that someone post this to the list.  The 13:30 today time, however, has passed, and the present proposal is a discussion after the 8 am meeting tomorrow.  Any interested parties in either the seed laser swap proposed by Grames or the C-slit contraction test I proposed should consider a discussion before tomorrow's 07:45 discussion or after the usual 08:00 morning meeting.

Feel free to mention any other bteam-ish items you find worthy of bringing to public attention, even though meaningful discussion of them may not be immediately available.

Thank you.

Michael Tiefenback

________________________________
From: Camille Ginsburg <ginsburg at jlab.org>
Sent: Tuesday, March 10, 2020 12:06
To: Michael Tiefenback <tiefen at jlab.org>; Matthew Bickley <bickley at jlab.org>; bteam at jlab.org <bteam at jlab.org>
Subject: Re: no bteam today.

Dear Michael, Dear Colleagues,

I suggest we get together at the time of the B-team meeting to discuss this proposal and try to understand schedule constraints.

I consider this problem high priority for CEBAF operations.

We may summarize the meeting in an email for those unable to attend, for their comments and contributions.

Best wishes,
Camille
________________________________
From: BTeam <bteam-bounces at jlab.org> on behalf of Michael Tiefenback <tiefen at jlab.org>
Sent: Tuesday, March 10, 2020 9:36 AM
To: Matthew Bickley <bickley at jlab.org>; bteam at jlab.org <bteam at jlab.org>
Subject: Re: [BTeam] no bteam today.

Can we PLEASE, PLEASE narrow up the C slit while delivering 30 uA to the Hall C dump as in the outline I submitted for review to some portion of our membersihp?
Outline:
Deliver 30 uA to C
Turn A off to allow increased current draw from C laser
read BLMs
Narrow slit to restrict to 15 uA
Raise laser intensity to restore 30 uA
read BLMs
narrow slit to restrict once more to 15 uA
as available, raise laser intensity to restore 30 uA to C
read BLMs
If laser maxed out before 30 uA available, open slit to give 30 uA at max laser
reduce current lock setting to 25 uA
slowly open slit to return to open condition while current lock reduces laser intensity
compare BLMs along the way

This is something which should take not very many minutes and for which I asked feedback quite a few days ago.  Feedback now?  We do not have to wait for Hall C to come back to get this information.  It is not exactly the "A laser through C slit" test, but it is a "restrict temporal gate at C chopper" test which strongly overlaps.  As time is available, one might also reduce the pre-buncher to gain additional information, but this is not a first-line part of the proposed test.  This will give us useful information as outlined above.

Michael Tiefenback

________________________________
From: BTeam <bteam-bounces at jlab.org> on behalf of Matthew Bickley <bickley at jlab.org>
Sent: Tuesday, March 10, 2020 09:27
To: bteam at jlab.org <bteam at jlab.org>
Subject: Re: [BTeam] no bteam today.

I'll add some context that Yves shared with me before he headed home after being here over night. Following our earlier studies we have pretty high confidence that the activation we are seeing in the arcs is the result of the width of the beam pulses coming from the C laser. The last test we want to execute, which was scheduled but we ran out of time for, is to send the C laser through the A slit. That will need to be done to confirm our understanding of the source of the activation. Unfortunately, because the current experiment in Hall C is nearly complete we won't have time to perform the study before this run is over. We should expect to perform it late next week at the earliest, once the next run starts in Hall C following their experimental equipment change. When we hold our BTeam meeting next week we'll refine our planning for this test as well as discuss additional tests that could be done to understand machine performance.

Matt

________________________________
From: BTeam <bteam-bounces at jlab.org> on behalf of Yves Roblin <roblin at jlab.org>
Sent: Tuesday, March 10, 2020 8:38 AM
To: bteam at jlab.org <bteam at jlab.org>
Subject: [BTeam] no bteam today.

We will have one the week after that to present the result of previous beam studies and plan for next round of studies.


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