[Halla_running] [New Logentry] RC update

[chandan at jlab.org]

Logentry Text:
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Dear Collaborators,

We got beam back at 16:00 yesterday. Restored high current beam in the hall with 1% Carbon target around 17:00. 
Beam spot on target was 136(x)by 150(y)micrometer. 
Then handed over to compton people for centering beam with LASER and collimator. This went upto 7 pm.
Then HallD started having BLM trips when HallA was up (https://logbooks.jlab.org/entry/3792731).
Around that time we were in situation to run overnight with lower current.
But MCC worked with optics-on-call and solved that problem (https://logbooks.jlab.org/entry/3792853).
We started production around 9:10pm with FFB on, RF on, FF DAC off and BMod on.
The main detector yield (>0.03 V/mciroAmp), width (regressed <800 ppm), slope (~40 ppm/micrometer) are looks good.
High current raster check looks good (uniform 2D distribution of beam at target). We have about two hours of production data before 1L07-FCC lost communication.
(https://logbooks.jlab.org/entry/3792834).

In the night we have requested escorted access to reverse a change made to the Compton laser power earlier today to increase detector resolution.
 We got back beam at 6 am in the morning and requested for harp scan. But ioc control with the harp wire is lost. Took hall access and reboot the ioc.
MCC was not able to communicate with that ioc (software issue). Fixed that around 8 am.
Harp scan on 1HA1H04A and 1HA1H04B wires are performed. 
Established high current with 1%C target. At 8:45 am started production with Ca-48 target.

Last night we have decreased current ramp rate to 10 microAmp/s (per MCC's request) to avoid trips. In the morning we have requested to increase to 20 microAmp/s and they did it.
The plan is to continue production.

We will have our usual meeting upstairs in the counting house at 3:15 PM today. Bluejeans link for remote participants: https://bluejeans.com/256205934


Chandan Ghosh
(Hall A Run Coordinator)


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This is a plain text email for clients that cannot display HTML.  The full logentry can be found online at https://logbooks.jlab.org/entry/3793225
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