[BTeam] [EXTERNAL] Follow up on Hall B Halo Rates Troubleshooting

[Brian Freeman]

Also the slow drift in rates means that there is some other slow drift somewhere upstream in the horizontal positions, I will take a look at this today as well.

-Brian
________________________________
From: Brian Freeman <bfreeman at jlab.org>
Sent: Sunday, August 30, 2020 6:36 AM
To: Sebastian Kuhn <kuhn at jlab.org>
Cc: Michael Tiefenback <tiefen at jlab.org>; Dennis Turner <dturner at jlab.org>; HyeKyoung Park <hkpark at jlab.org>; bteam at jlab.org <bteam at jlab.org>; Stepan Stepanyan <stepanya at jlab.org>; Paul Vasilauskis <vasilaus at jlab.org>; Mohammad Hattawy <mohammad.hattawy at gmail.com>
Subject: Re: [BTeam] [EXTERNAL] Follow up on Hall B Halo Rates Troubleshooting

So it looks like this was it..... just a bad angle going into the target.

It was reported however, that the 2C21 H corrector is railed?

We can help this out by using an upstream corrector. I can look at this today.

-Brian
________________________________
From: Sebastian Kuhn <kuhn at jlab.org>
Sent: Friday, August 28, 2020 9:28 AM
To: Brian Freeman <bfreeman at jlab.org>
Cc: Michael Tiefenback <tiefen at jlab.org>; Dennis Turner <dturner at jlab.org>; HyeKyoung Park <hkpark at jlab.org>; bteam at jlab.org <bteam at jlab.org>; Stepan Stepanyan <stepanya at jlab.org>; Paul Vasilauskis <vasilaus at jlab.org>; Mohammad Hattawy <mohammad.hattawy at gmail.com>
Subject: Re: [BTeam] [EXTERNAL] Follow up on Hall B Halo Rates Troubleshooting

Just a small addition: We have already tried re-centering the beam on the target structure - TWICE - and also changing the angle with which it comes into the Hall. Nothing changed the background, and we could not find any obstructions other than the known target walls, which we avoid by centering the beam.

- Sebastian

On Aug 28, 2020, at 6:01 AM, Brian Freeman <bfreeman at jlab.org<mailto:bfreeman at jlab.org>> wrote:


  1.  We could simply try angle and position changes into the target ? It looks like things got really noisy after a target change in the hall on the 15th, probably a coincidence (https://logbooks.jlab.org/entry/3835820) . I believe that the Midstream counters sit around the Target somewhere, and Downstream counters are after CLAS. So perhaps we just have a bad angle going into the Target? ( 1hr )

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