[Hps] Well Done HPS!

[Jaros, John A.]

Dear HPS,

Our Engineering Run ended this morning at 6AM after an extremely productive 2 week extension of the CEBAF program. HPS successfully recorded more than 5 B triggers with the full detector, much of it at the design setting where the silicon sits just 500 um from the beam center. It worked! (... you never doubted!)

This is a really spectacular outcome, and the culmination of a huge amount of work and dedication by all of HPS. The collaborative  support of the machine staff and operators in providing us with tiny, stable, halo-free beams and good accelerator uptime was critical to this success, and our heartfelt thanks go out to them. We thank also the JLAB management for their continued support of our experiment, for granting us an extension, and for effectively balancing CLAS12 and HPS goals throughout this time.  Nights and weekends actually worked!

It really does take a collaboration. The success of this Spring's run rests on all of our shoulders. Special thanks must go to the JLAB crew and the subsystem experts who were omnipresent in the counting house and fought all the daily battles. Ditto the trigger team, the DAQ team, the ECal team and the SVT team.  Adaptability and last minute improvements in the DAQ and trigger led us to higher and more inclusive trigger rates. Last minute tweaking all around made steady improvements in the data quality. Thanks to the software and analysis efforts, data recording was smooth, monitoring plots were in place for the final running, we have had a first look at our data,  and we have pass0 reconstruction underway. Slow controls succeeded to the point of moving out of the limelight, and providing us standard and reliable tools that we already take for granted. The willingness of everyone to staff shifts when machine uptime was questionable, and again when a run extension severely tested travel budgets and personal stamina, made this all work.

We have a long way to go to understand our data and see what physics it reveals. But we have come a very long way. We have a successful experiment and a bright future. 

Congratulations HPS!

Maurik, John, and Stepan