Commissioning and running of sPHENIX

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

Hello sPHENIXians,

This week marks the start of cryo-week #16 (out of 19 + 6 = 25).     

Extra thanks to Sanghoon Lim who has just finished as Period Coordinator, and welcome to Stefan Bathe starting as our new Period Coordinator (pictured below).   I am making a trip home to Boulder from this Tuesday evening through Monday morning.   I will remain connected, and Stefan will be in charge in 1008.  Also welcome to our latest spectacular sPHENIX shift crew (pictured below).   

This past week has been a standout in many ways.    On the TPC front, the necessary equipment, checks, and safety approval was all completed and the isobutane (at the prescribed 5% level) started flowing into the TPC on Saturday, July 27, 2024.     After 48 hours for the gas volume to turn over multiple times, sPHENIX requested six hours of no beam to turn on the TPC high voltage and take cosmic triggered data on Monday, July 29, 2024.     Experts on the detector, electronics, reconstruction, tracking worked together and by Tuesday morning had verified the nominal high voltage range with cosmics for good signals.     The TPC group met and agreed to proceed with the sPHENIX request for a 6x6 bunch store at zero crossing for sPHENIX to collect the first TPC data with beam and the new gas mixture.    I would like to emphasize that all of the TPC meetings and discussions are being openly advertised and slides posted and documented -- the collaboration needs to be part of this process.    As of this writing, the beam data is already being analyzed and there will be another discussion tomorrow with next steps to be decided.     I would like to emphasize the amazing fortitude and work to get to this point, and at the same time, sPHENIX is at the beginning of  commissioning the TPC for physics - including necessary new firmware, zero suppressing, and data throughput improvements.

On the rest of the detector, this past week has been record breaking, and  we now have of 55 pb^-1 over all z-vertices and 8.5 pb^-1 for |z| < 10 cm.     sPHENIX has now sampled trillions of proton-proton collisions for rare high energy jets and photons.     The data taking efficiency has significantly improved due to hard work by experts and shift crews together.     The INTT has run in full streaming mode and additional firmware updates to resolve a BCO issue are being fully tested.



It has already been a  long run and many people are wearing out.    Make sure to take a break, step up when needed, and let's get more people actively involved.

Below is the link to the weekly RHIC Coordination meeting presentations from sPHENIX.  

https://indico.bnl.gov/event/20768/contributions/94678/attachments/56261/96283/sPHENIXRunCoordinator_RHICCoordinationMeeting2024_07302024.pdf

Never give up!

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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