Commissioning and running of sPHENIX

[Jamie Nagle <jamie.nagle AT colorado.edu>]

Hello sPHENIXians,

This week marks the start of cryo-week #20 (out of 19 + 6 = 25).     The current pp running goes until September 16, 2024 and then just 3 weeks of AuAu, i.e., until October 7, 2024.    Under this plan there are 19 days left of pp running.    In my presentation at the Executive Council meeting last week (linked below), I recommended requesting 4 additional cryo-weeks of pp running, in addition to delaying the NPP Program Advisory Committee meeting and associated handing in of the 2025 sPHENIX Beam Use Proposal.    In talking with the ALD Abhay Deshpande yesterday in 1008, it sounds likely that some extension is in the cards and the NPP PAC meeting will be delayed -- both good news items.

https://indico.bnl.gov/event/24602/contributions/95757/attachments/56779/97268/sPHENIXRunCoordinator_ECupdate08212024.pdf

sPHENIX has been running over the last two weeks at +1.5 mrad with approximately 50% of the collisions within |z|<10 cm.    C-AD has delivered good luminosity stores, and are keeping the stores for 8 hours after physics is declared.    The full luminosity is being sampled by the rare jet/photon/upsilon triggers, while the "streaming" tracking output (via MVTX, INTT full streaming and TPC/TPOT extended readout) is now recording about 20% of all collisions (up from 10% the week before).     sPHENIX also successfully took B=0 data for tracking detector alignment (thanks to Kin Yip for fast thinking when the magnet tripped off).     Key checks on the overall data quality are underway and are on the critical path to ensuring that we are taking the highest quality bits to disk.    This point cannot be emphasized enough.

If we get some additional running time, improve our uptime, and make incremental improvements to the 20% streaming (maybe towards a 25-30% goal), we might be able to get to 50% of the open heavy flavor goal (which was 4.5 pb^-1 within |z|<10cm).   There is a  balancing act of making these improvements while not destabilizing the DAQ/readout and without super-duper-overtaxing our experts (note that they are already superovertaxed).      

The graph below shows a summary of the run so far and the time remaining (not yet counting on any additional running time).

Below are the links to the weekly RHIC Coordination meeting presentations from sPHENIX and C-AD.  

https://indico.bnl.gov/event/20768/contributions/95930/attachments/56905/97548/sPHENIXRunCoordinator_RHICCoordinationMeeting2024_08272024.pdf

https://indico.bnl.gov/event/20768/contributions/95929/attachments/56902/97544/RHIC_Coordination_Meeting_XXX-2.pdf

Lastly, welcome to our new unflinching sPHENIX shift crew (picture below) and new Period Coordinator Yeonju Go (picture below).   Thanks to our outgoing Period Coordinator Chris Pinkenburg for doing a great job, and of course all the work he does for sPHENIX.

Sincerely,

Jamie

sPHENIX Run Coordinator 2024

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|| James L. Nagle   
|| Professor of Physics, University of Colorado Boulder

|| EMAIL:   jamie.nagle AT colorado.edu
|| SKYPE:  jamie-nagle        
|| WEB:      http://spot.colorado.edu/~naglej 
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