[BTeam] minutes of meeting 03/21/2020

[Michael Tiefenback]

All:

I will argue at the meeting that we should make at least a symbolic attempt to get the beam through all passes on startup, with the purpose of making a comparison fopt data set without any special attempts at re-matching the optics.  I expect the acceleration profile to be somewhat different, and that therefore the optics will be different at some unspecified level.  But it would be useful to know how closely the machine comes back from such a lengthy down.

It should not take long to determine how high in pass count we can go, but I think that one should expect easy transport (steering corrections only) up to about 6R or perhaps the 7R dumplet.  The fourth pass through the NL is where I'd expect scraping to occur as a result of cumulative optics variations, and transport across the 7L (which is in practice very like a long drift) might suffer significantly.

Michael Tiefenback

________________________________
From: BTeam <bteam-bounces at jlab.org> on behalf of Brian Freeman <bfreeman at jlab.org>
Sent: Tuesday, April 28, 2020 07:00
To: Yves Roblin <roblin at jlab.org>; bteam at jlab.org <bteam at jlab.org>
Subject: Re: [BTeam] minutes of meeting 03/21/2020

All,

Here is the latest schedule:

https://www.jlab.org/accel/ops/ganttproject/2020/2020_Covid19Recovery-chart.html

We will go with Yves option 2, which is stop setup after we get to 3R and try the M56 lattices that will be presented by Alex today.

I also am attaching a PDF version.

Cheers,
-Brian


________________________________
From: BTeam <bteam-bounces at jlab.org> on behalf of Yves Roblin <roblin at jlab.org>
Sent: Tuesday, April 21, 2020 2:11 PM
To: bteam at jlab.org <bteam at jlab.org>
Subject: [BTeam] minutes of meeting 03/21/2020

We discussed the machine restore. Two plans were presented.

Option 1), spin up to 5 passes restoring from previous setup then launch into beam studies
to assess the correct M56 for ARC1 but not download it.

Option 2) spin up to 3R, try all the M56 lattices to find which one results in least correction. Download it, match it and resume setup.

If going through option 2) also readjust the bcom from the start  so that higher passes dont end up 2.5 % off.

Using the archiver, we can construct a baseline of what the east arc BLM activity was last time we ran with tune beam. We can refer to that to see if we reduce loss

Both option 1) and 2) take about 2 weeks but option 1) can be shortened if we drop the beam studies since we can always do some of that later during regularly scheduled beam studies.

Before spin up, we can walk the tunnel to check for misplaced/fallen shims in dipoles as well as any alignment issues on the east side.


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