Muon g-2 Inflector

AEM Meeting11/25/2013

Chris PollyMuon g-2 Project Manager

Chris Polly All Experimenters Meeting 2

Muon g-2 Inflector

outer coil

yoke coil

Inflector used to bring beam from outside storage ring and onto an interior orbit

11 November 2013

Chris Polly All Experimenters Meeting 3

Pictures

Closed windings cause multiple scattering -> beam blows up and about half of muons lost

About 2m long and as big around as a football

Inserted inside cryostat that is part of a special vacuum chamber

11 November 2013

Chris Polly All Experimenters Meeting 4

Technically challenging- Geometrically tight region- Large Lorentz forces when magnet is powered- Has to produce 1.5T bucking field to cancel main field- Can’t perturb muon storage ring by more than ~1ppm so whole thing is wrapped in a superconducting shield

- Coil winding has to be self-cancelling to the point that the stray fields don’t saturate the superconducting shield- Design interfaces with optics of final beamline

11 November 2013

Chris Polly All Experimenters Meeting 5

Simulated improvements

- Have known about this factor of 2 from back-of-the-envelope calculations used in the proposal- Have since developed a full Geant 4 model of the ring- Some very nice work by Thomas Gadfort has confirmed the potential gains

11 November 2013

Chris Polly All Experimenters Meeting 6

Reminder of rates at FNAL

Achieving required statistics is a primary concern - Need a factor 21 more statistics than BNL - Beam power reduced by 4

Need a factor of 85 improvement in integrated beam coming from many other factors - Collection of pions from lens - Capture of decay muons in FODO channel - pπ closer to magic momentum - Longer decay channel - Increased injection efficiency - Earlier start time of fits - Longer runtime

What is a new inflector worth? - Estimate ~$3M/yr operation cost - Hard to put a price on expanded physics scope

Ratio of beam powers BNL/FNAL:4e12 protons/fill * (12 fills / 2.7s) * 24 GeV1e12 protons/fill * (16 fills / 1.3s) * 8 GeV = 4.3

11 November 2013

Chris Polly All Experimenters Meeting 7

So why is a new one needed?1) If for some reason we don’t achieve all of the rate factors assumed in the prior page then this extra factor of 2 might be the only thing saving the experiment from significant additional operating costs and years of run time.

2) The existing inflector represents a single point of potential failure with no backup. Had developed a He leak in E821 which we think is in the lead can and should be repairable, but not conclusively shown at this point.

3) Even if all of the other beam improvements come through, we can use the factor of 2 in rate to do more physics. Options included

- Reducing the error on the μ- experiment by another sqrt(2) if systematics are shown to be controlled at better-than-expected level

- Better collimation of muon beam to be in region where magnetic field is more uniform

- Re-running μ- measurement a second time with a different set of environmental conditions to verify systematics are understood

- Run the experiment with μ+ for a test of CPT violation

11 November 2013

Chris Polly All Experimenters Meeting 8

Status

- Rough estimate $1.5-2.0M- Not in baseline plan shown at CD-1 because conceptual design did not exist- Included in risk registry as $1.5M +/0 $0.5M risk with 25-75% probability- We were hoping that the UK would get funded to be a major player in developing this intellectually challenging and important piece of equipment- Found out that the UK did get approved for $1.8M in funding for straw tracking, but STFC rejected the portion having to do with inflector- Still some possibility for foreign investment from UK or Korea, but we have to make this happen ourselves- Have hired Brett Parker and BNL group to lead winding design- Need to identify who at FNAL can be responsible for leading the effort to produce the fully-integrated device and be responsible for it during operations

11 November 2013

Chris Polly All Experimenters Meeting 9

BNL winding technology

- Rough estimate $1.5-2.0M- Not in baseline plan shown at CD-1 because conceptual design did not exist- Included in risk registry as $1.5M +/0 $0.5M risk with 25-75% probability- We were hoping that the UK would get funded to be a major player in developing thi

11 November 2013

Chris Polly All Experimenters Meeting 10

Schedule presented at DOE CD-1

CD-0

Forecast ObjectiveKPPs Satisfied

CD-1 CD-2/3a CD-3

Conceptual Design

PrelimDesign

CD 3a Work

FinalDesign

Ring/Field/Detector Implementation

Accelerator Implementation

Close-out

CD-4Forecast

Includes controls to MC-1 bldg, possible advancement of D30 straight reconfiguration

xNatalie Zaysoff

xNatalie Zaysoff

Ring & DetectorsReady for Ops

AcceleratorComplete

MC-1 Building Design and Construction

Ring Reassembly

Construction of NSF/Early Career funded detector components

xNatalie Zaysoff

LX3: MC-1 BO, StartRing Reassembly

LX3: Cryo Plant Ready, Cool Ring

xNatalie Zaysoff

xNatalie Zaysoff

Cool-Down

Field Shimming

Install vacuum chambers, equipment in gap, align, establish vacuum

Install remaining ring & detector subsystems

Controls to MC-1

Accelerator Beamlines, Target, Controls, Safety Systems

11 November 2013

Chris Polly All Experimenters Meeting 11

Schedule presented at DOE CD-1

CD-0

Forecast ObjectiveKPPs Satisfied

CD-1 CD-2/3a CD-3

Conceptual Design

PrelimDesign

CD 3a Work

FinalDesign

Ring/Field/Detector Implementation

Accelerator Implementation

Close-out

CD-4Forecast

Includes controls to MC-1 bldg, possible advancement of D30 straight reconfiguration

xNatalie Zaysoff

xNatalie Zaysoff

Ring & Det.Ready for Ops

AcceleratorComplete

MC-1 Building Design and Construction

Ring Reassembly

Construction of NSF/Early Career funded detector components

xNatalie Zaysoff

LX3: MC-1 BO, StartRing Reassembly

LX3: Cryo Plant Ready, Cool Ring

xNatalie Zaysoff

xNatalie Zaysoff

Cool-Down

Field Shimming

Install vacuum chambers, equipment in gap, align, establish vacuum

Install remaining ring & detector subsystems

11 November 2013