June 17, 2004 / Collab Meeting

Strategy to reduce uncertainty on a to < 0.25 ppmDavid Hertzog

University of Illinois at Urbana-Champaign

Present data rates

How to achieve higher rates

Statistical and systematic targets

Timescales and Support

1 ppm contours

June 17, 2004 / Collab Meeting

How to achieve a factor of > 2 reduction in world-average a uncertainty

[ppm]Final uncertainty from E821 0.54 2001 systematic from a 0.21

2001 systematic from p 0.17

Target statistical uncertainty 0.20 Target systematic from a 0.10Target systematic from p 0.10

Target E969 overall uncertainty 0.25Final BNL Goal (E821 + E969) 0.22

Implications• Data increase necessary compared to 2001 - run x 12

• Reduction of systematic uncertainties by factor of 2

• More muons are necessary

• Q (integrated) method probable main mode

Goal

June 17, 2004 / Collab Meeting

My rate calculation – standard conditions1. 34 B counts; A = 0.4 → 0.2 ppm statistical (my sim/fit)

2. AGS Intensity = 50 Tp (avg)

3. AGS Rep rate = 2.7 s

4. AGS fill structure = 12;

5. 10,000 +/fill/50 Tp

6. Acceptance E > 1.8 GeV = 0.12 Item Value

Counts needed 3.4 E10

Correct for T0 (30 s) 5.4 E10

Correct for acceptance 4.5E11

Fills @ 10k/fill 4.5E7

Hours required (1600/h) 2812 h

Run-time “uptime” = 0.7 4000 h

Weeks @ 100 h/week 40 weeks

Setup 3-4 weeks

Total 44 weeks

Reduce by More Muon Factor

June 17, 2004 / Collab Meeting

Conservative changes yield factor of 2.6

Item Comment Factor

Replace traceback with calorimeter

Vacuum chamber change ( $50 k)

24 / 23 = 1.04

Use positive muons + cross section is higher 1.2

Add 4th kicker @ 270º(see plot below)

Increased stored muon fraction Fabrication and tracking studies are necessary ( $250 k)

?????

Open up inflector ends(design report)

Task looks reasonable but work must begin ASAP ( $750 k)

1.75

Total 2.2 + ??

Present: CLOSED End Proposed: OPEN End

June 17, 2004 / Collab Meeting

BNL Storage Ring

incoming muons

Quads

KICK

0 500 ns

100kV

4th Kicker

3 Kickers

Present Infle

ctor

Proposed Infle

ctor

June 17, 2004 / Collab Meeting

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

June 17, 2004 / Collab Meeting

Next REALLY big idea: Use backward pion decays Peter (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 GeV

5.22 GeV

GeV

The “Quad” section

This needs work to go to

5.2 GeV

June 17, 2004 / Collab Meeting

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

June 17, 2004 / Collab Meeting

Maintenance and conventional upgrade tasks should begin soon on conventional systems

e+

TIME

Co

un

ts

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

June 17, 2004 / Collab Meeting

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

Systematic uncertainty (ppm) 1998 1999 2000 2001 200X

Goal

Magnetic field – p 0.5 0.4 0.24 0.17 0.10

Anomalous precession – a 0.8 0.3 0.3 0.21 0.10

June 17, 2004 / Collab Meeting

Running hours, schedule and costs Time required for - 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)

Activity Year

Proposal / PAC 2004

Obtain $$ / start R&D 2005

R&D and Construction 2006

Construction

Commissioning

2007

Full run 2008