FMS Readiness for Run 11 Stephen Trentalange

General Plan May: Hardware Investigation June: Operation with Cosmic Rays/LEDs Exercise entire system thru DAQ July-August: Analysis of LED Data September: Fabrication of PMT Bases at PSU October: Repair of Bases/Dead Channels Fix of DAQ Runaway Problem Hardware Review of FPDs November: Changes to FMS Triggering Mechanical Procedures: Closing FMS

Hardware Operations Learned operation of HV, PMTs, QTs/DSMs, LED systems Access and operation of FMS Software: masks/offsets for QTs/DSMs DAQ/Trigger Operations: Cosmic Rays and LED data Verified HV, LED, DAQ and Trigger Maps System works: several people trained for operations: Steve Heppelmann, Jinguo Ma, Len Eun + 7 PSU undergrads Identification of dead channels Large Cells: ~21 Dead 21/788 = 2.7% ~23 Gain Problems 23/788 = 2.9% Total 44/788 = 5.6% Small Cells: ~23 Problems 23/476 = 4.8% After repairs est. 14/476 = 2.9%

FMS Event Display: Cosmic Rays Cosmos

LED Data: Identify Gain Shifts/Dead Channels/HV Gain Curves (Zero Field)

FMS Problem Channels

Constant ET gains Large cell gains in the range 0.0450 GeV/chan to can be configured for constant ET = 0.00660 GeV/chan Small cell gains in the range 0.0384 GeV/chan to 0.1099 GeV/chan can be configured for constant ET = 0.00330 GeV/chan Full-scale ET = 27 GeV/c for large cells and 13.5 GeV/c for small cells Same channel gains provide constant ET independent of zvertex Actual ET/channel is higher(lower) for positive(negative) zvertex FMS Trigger Update III

Proposed scheme Eight overlapping jet patches (JP), each covering ~900 in azimuth Large enough patches with sufficient overlap to “catch everything” Maximize the efficiency for the rare, highest energy events Board sum (BSum) triggers Approximate capabilities of the current cluster trigger Provide efficiency for “inclusive … meson” measurements at lower energies where the JP trigger rates would be too high High tower triggers For calibration and diagnostics Possible di-jet and J/ψ trigger (two non-adjacent JP0 patches) FMS Jet Patch Trigger

Anticipated rates for constant ET calibration For scale, ET = 4.3 GeV/c corresponds to an energy of 91 GeV at η = 3.75 39 GeV at η = 2.9 FMS Trigger Update III

A possible strategy for the transverse period 600 Hz, essentially all fast-detector events, is a very reasonable FMS bandwidth allocation for the transverse period Allocate 200 Hz to JP triggers 200 Hz to small cell BSum triggers 100 Hz to large cell BSum triggers Set take-all thresholds to saturate the bandwidth at ~3.5 MHz pp collisions (expected max lumi at end of transverse period) Set prescale thresholds fill bandwidth while accepting 1/10 at ~1.7 MHz pp collisions (expected ave lumi for weeks 2-4) Allocate 100 Hz for remaining triggers (HT, FPDE, di-jet, etc.) What was the FPD gain/channel during Run 9? FMS Gains and Trigger

Run 11 Projections: 20 pb-1

Problems Ahead Cannot produce real gain curves now: Requires DX/STAR magnets on. Requires beam time. Must calibrate at beginning of pp run. Transverse run is before longitudinal Must solve “runaway” DAQ problem Operate FPD in October (Jingguo and Stephen) Mechanical movement of FMS/FPD Fix FMS small cell PMTs Recable/Reprogram FMS trigger