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1 ppm contours. Strategy to reduce uncertainty on a m to < 0.25 ppm. David Hertzog University of Illinois at Urbana-Champaign. Present data rates How to achieve higher rates Statistical and systematic targets Timescales and Support.
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1ppmcontours Strategy to reduce uncertainty on am to < 0.25 ppm David Hertzog University of Illinois at Urbana-Champaign • Present data rates • How to achieve higher rates • Statistical and systematic targets • Timescales and Support
How to achieve a factor of > 2 reduction in world-average am uncertainty [ppm] Final uncertainty from E821 0.54 2001systematic from wa 0.21 2001 systematic from wp 0.17 Target statistical uncertainty 0.20 Target systematic from wa 0.10 Target systematic from wp 0.10 Target E969 overall uncertainty 0.25 Final BNL Goal (E821 + E969) 0.22 Goal • Implications • Data increase necessary compared to 2001 m- run x 12 • Reduction of systematic uncertainties by factor of 2 • More muons are necessary • Q (integrated) method probable main mode
My rate calculation – standard conditions • 34 B counts; A = 0.4 → 0.2 ppm statistical (my sim/fit) • AGS Intensity = 50 Tp (avg) • AGS Rep rate = 2.7 s • AGS fill structure = 12; • 10,000 m+/fill/50 Tp • Acceptance Em > 1.8 GeV = 0.12 Reduce by More Muon Factor
Conservative changes yield factor of 2.6 Proposed: OPEN End Present: CLOSED End
100 kV KICK 0 500 ns incoming muons Quads Proposed Inflector 4th Kicker BNL Storage Ring 3 Kickers Present Inflector
Next big idea: Double quads in FODO section Hugh & Paul • This gives a reliable factor of 4 more muons • Even more quads under consideration now • Questions of momentum acceptance need to be addressed New Beamline Transport
Next REALLY big idea: Use backward pion decaysPeter (Kammel) & Paul • Gain: Another factor of 2 • NO FLASH (no pions, no protons into ring) • Double checking kinematics • Some significant changes to upstream beamline 5.22 GeV p The “Quad” section This needs work to go to 5.2 GeV 5.22 GeV p + 3.1 GeV m 3.1 GeV m
Summary of possibilities that will be considered Conservative = 2 Quad double = 2 Backward Decay = 4 Net = 16 (!) all of this can’t be right Basic conclusion: We can find a factor of at least 5 among this set of topics Basic reality: Some of them won’t work out
Counts TIME Maintenance and conventional upgrade tasks should begin soon on conventional systems e+ New detectors and hodoscopes? New WFDs New DAQ Plan B refrigerator a must Kicker #1 repair Quad maintenance Ring de-rusting Probe replacements Trolley external calibration
Systematic Error Evolution • Field improvements will involve special trolley external calibrations, temperature stability of room, replacement of many fixed probes • Precession improvements will involve new scraping scheme, lower thresholds, more complete digitization periods, better energy calibration
Running hours, schedule and costs • Time required for m- running to 0.66 ppm (statistical) • 1000 h (+ setup) = 1250 h • Time required to achieve 0.20 ppm with factor of 5 increase in data rate • 2200 h + setup = 2500 h (25 w) • Ready 2 years after funding for shot on demand beam tuning and 2 weeks physics commissioning run • Following year, take 20+ weeks (time depends on factors)