[Hallc_running] (Not your usual) Call for shifts for A1n/d2n in Hall C

Xiaochao Zheng xiaochao at jlab.org
Fri Feb 21 11:20:22 EST 2020

Dear All:

Well, a week is not complete without churning out a A1n/d2n Newsletter, so here we are:

Previously I have compared running an experiment to running a road race, though strictly speaking it is not any race: It is a prestigious race like the Boston or the New York Marathon (we did have to work hard to be approved by the PAC). Now, as many of you have probably realized: our runners -- Brianna and Dutch -- have found their race condition not as ideal as they hoped. They have faced strong wind (extended down), pouring rain (high trip rate), a snow storm (ESR crash), and competition with other friendly runners (A, B and C taking turns to get their fill of 1-pass beam).  However, like I said last time: This is it! we have to finish the race and we have to finish strong! And so they pressed on.

What I did not mention is that Dutch, one of our best runners, had one ill-fitting shoe (its longitudinal polarization was never as high as the transverse one). Because the cost of fixing the shoe was high, Dutch never stopped at an aid station. Rather it limped and hopped and at some point almost crawled, and finished bravely its section of the relay. When we took it out ten days ago, fully covered by salt dust, it could finally rest at its retirement home (the hall) but at the same time, we knew it had not been run to its full potential.

Now here are the good news: The ill-fitting shoe was finally fixed and BigBrother does not need to limp like Dutch did!  What a great relief we all felt! Since this past Monday, BigBrother has been running with a consistent (54-55)% longitudinal polarization under 30uA beam, pushing our kin3/C production with flying speed. An elite runner is finally flying!

I was always told the legend that "cell Picard saved E154". Looking at the target polarization plot (below), I never fully understood, until now, how can one of nine cells saved a whole experiment. But now I do: Because of the I*Pt^2 factor in the FOM, every 10% increase in the target polarization is like gaining 20% in beam time. And every running day of BigBrother is like 1.6 or even two days of Dutch!

To those of you helping out on the shifts (Run Coordinators included): You are not simply sitting shifts. You are the caretaker of our best cells, and you are the caretaker of the experiment. Every single task you do, whether it is an NMR measurement, starting/stopping the run, glancing over online monitoring and analysis plots, or staring at the BPM charts, and most importantly carrying out the beam checkout procedure, you are helping us to ensure a successful running of the experiment. Please, sign up for more shifts, come see BigBrother flying!


call me odd if you wish, I am still one spokesperson of A1n


(Figure credit: Mike Romalis Ph.D. thesis. Cells used: Dave, Riker, Bob, SMC, Generals, Hermes, Prelims, Chance, and Picard)
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mailman.jlab.org/pipermail/hallc_running/attachments/20200221/78a899fe/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image.png
Type: image/png
Size: 26967 bytes
Desc: image.png
URL: <https://mailman.jlab.org/pipermail/hallc_running/attachments/20200221/78a899fe/attachment-0001.png>

More information about the Hallc_running mailing list