AEM Meeting E906/SeaQuest Kazutaka Nakahara University of Maryland 1/13/2014

Major Activities Beam tuning on-going – productive meeting with Accelerator group to find ways to suppress the low (60/360Hz) and high (53MHz) frequency noise. Elevated radiation level inside hall under study. Main focus (on the side of the experiment) over the past few weeks was to understand the trigger system.

Beam Quality Meeting between experiment and members of the Accelerator group on 12/9/2013. Beam tuning since has shown improvement in beam quality. Power spectrum shows marked decrease in the 360Hz resonance w.r.t baseline. Duty also shows improvement from ~15%  25-30%. 12/9/2013 Today

NM4 Radiation Levels 7:30 Tuesday 7 JanuaryRemove Cherenkov, put in clear through pipe and pump down pipe 7:30 Wednesday 8 JanuaryStart beam to SeaQuest measure radiation as function of beam intensity Insert Al Foil near target to simulate Cherenkov at target Start beam to SeaQuest to measure radiation as function of beam intensity 7:30 Thursday 9 JanuaryReinstall Cherenkov in old location, pump down and resume running -Right now, we are getting ~3E11 ppp as seen on F:NM3ION. -Radiation monitors see significant increases (i.e they can trip) beyond this value. -What’s causing this? First suspect: Cerenkov monitor (0.6% interaction length, few hundred feet upstream of SeaQuest target). Bottom line: It looks like the Cerenkov monitor maybe the cause of the elevated radiation levels in the hall at higher beam current.  New home found. Design completed and in fabrication.

Detector St 2 chamber X/X’ fixed during 3-day access. All chambers working. All hodoscopes working. -Timed in -Plateaued

Trigger System We have multiple trigger firmware with different roads available: Target Drell-Yan Target J/Psi Dump Drell-Yan Dump J/Psi Level 1 – Check detector hits and timing to find matching roads Level 2 – Coincidence between top and bottom trajectories (di-muon) -Debugging – fixing mapping errors, timing errors, logic errors -Optimize – turn off “hot” roads that contain many hits (mostly noise)

Targets Targets being cycled between “no target”, 10% Fe, 10% C Liquid systems are ready to be turned on…assessing when to liquefy targets. Cryo-refrigerator cold head seals have a hour maintenance cycle (~ 8000 hours left over) – requires access and possibly extraction of targets from target tent.

Critical Path Items 1.Improve beam quality (duty factor > 2.Change Cerenkov location – achieve 1E13 ppp 3.Implement Splat-block Luminosity Counters 4.Understand the trigger system (consistency/logic check with Rates, Monte-Carlo and NIM trigger). After these are complete Liquefy targets