Commissioning and running of sPHENIX

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

Hello sPHENIXians,

This week marks the start of cryo-week #17 (out of 19 + 6 = 25).     

Another exciting week in the world of sPHENIX is in the history books.    Extra thanks to our Period Coordinator Stefan Bathe (pictured below), in particular covering as Run Coordinator during my escape back to Boulder, Colorado.     Also, welcome to our latest lionhearted sPHENIX shift crew (picture below).      I also want to give an extra shout out to Derek Anderson, who literally the last second covered a full week of owl shifts for a collaborator out due to covid-19, and also Joe Osborn (sPHENIX Analysis Coordinator) working 24/7 here in 1008 this critical past week.

On the TPC front, as a reminder, isobutane started flowing back on Saturday, July 27, 2024.     That was followed by raising the high voltage for cosmic data taking on Monday, July 29, 2024.      Over the past week, there have been successful operations with stores of 6x6, 28x28, and 56x56 bunches and the last one steered from 0 mrad to +1.5 mrad crossing.     The isobutane appears to be working (again noting all the hard work of the core TPC group and the people working on the safety approval).   Fast offline analysis indicates a good working point in terms of gains and without damage to the detector.     One set of resistor swaps was completed today and Thursday the second set will be done and then we all look forward to running with  the full 111x111 bunches.    The firmware to run with zero suppression and thus at high rate (potentially even full streaming) is on the critical path and good progress has been made on that front.    Additional work on load balancing and data throughput is also needed.     There are also key checks on BCOs for all streaming detectors, with an important discussion yesterday - and follow up action items.    As a reminder (see the linked slides below that repeat a point from last week's presentations), we expected an optimistic minimum two weeks to get the TPC into an initial form of physics data taking which might leave 5 weeks of pp running (assuming we reduce the last 6 weeks to only 3 weeks of AuAu).

sPHENIX continues to take important data without the TPC utilizing the selective jet and photon triggers, now with over 66 pb^-1 over all z-vertices and 10 pb^-1 within |z|< 10 cm.   Thus for pure calorimetric measurements we have already 50% more data than we expected going into this run.

It has already been a long run (sometimes hard to remember how long) and many people are wearing out and colds/covid-19/etc. are going around.   Make sure to take a break, step up when needed, and let's get more people actively involved.

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

https://indico.bnl.gov/event/20768/contributions/95111/attachments/56382/96517/sPHENIXRunCoordinator_RHICCoordinationMeeting2024_08062024.pdf

https://indico.bnl.gov/event/20768/contributions/95110/attachments/56363/96486/RHIC_Coordination_Meeting_XXVII.pdf

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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