The EMMA ProjectThe EMMA Project

Rob EdgecockRob EdgecockSTFC Rutherford Appleton Laboratory STFC Rutherford Appleton Laboratory

& Huddersfield University& Huddersfield University

OutlineOutline

• Why we needed to build EMMA

• How we got to where we are

• Design of the machine

• Construction

• Commissioning

• Conclusions

Motivation for EMMAMotivation for EMMA

• EMMA: linear non-scaling Fixed Field Alternating Gradient accelerator

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Motivation for EMMAMotivation for EMMA

Neutrino Factory

• Linear non-scaling FFAG- invented 1997/9, C.Johnstone et al- for muon acceleration in a Neutrino Factory

AccelerationAcceleration

Must be fast

Large acceptance

Motivation for EMMAMotivation for EMMA

/p

Path length

/p

Travel time

• Linear non-scaling FFAGs: - invented 1997/9 - for muon acceleration in a Neutrino Factory

- large dynamic aperture- small orbit excursion – higher frequency RF- CW acceleration

Motivation for EMMAMotivation for EMMA

Serpentine, bucketless, asynchronous, etc

acceleration

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14

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Fast resonance crossings

Motivation for EMMAMotivation for EMMA• Realised early on:

Other potential applications:- hadron therapy

- ADSR- other high power proton beam

applications

One or two issues:- tiny momentum compaction

- unique longitudinal dynamics- possible transverse dynamics

problems - resonance crossings- constraints on

construction - standard tracking codes not applicable - purpose built codes need benchmarking

• Must build one!

• Hence, EMMA

EMMA EvolutionEMMA Evolution

• NS-FFAGs invented 1997/99

• First mention of “EMMA”: FFAG03/NuFact03- 10-20 MeV electron model of muon FFAG

• Clear early on three things required:

funding

an electron beam

space

• Contacted MP in 2004

SRS injector

ERLP

• Developing ASTeC/DL from this point

EMMA LocationEMMA Location

Could meet all the EMMA requirements.

Space available in the hall.

All the required skills for design and construction available in

ASTeC and at DL.

International CollaborationInternational Collaboration

BNL, CERN, CI, FNAL, JAI, LPSC Grenoble, STFC, TRIUMF

FundingFunding

• First punt: FP6 NEST

April 2004

Very good review

Except – not a good match to the scheme

Maximum 2MEUR available

• Good practice for: RCUK Basic Technology Fund

Consortium building 2004-2006

Led to BASROC & CONFORM, PI Roger Barlow

First proposal: 4th April 2006

Serious work started for second proposal, submitted in July

Work led by STFC

Centred on ASTeC and TD at DL

Funded from 1st April 2007

EMMA LayoutEMMA Layout

Section of ALICE

Injection line: transports beam from ALICE to EMMA

EMMA ring

Diagnostics beam lineEMMAEMMA10-20 MeV

42 cells, doublet lattice19 RF Cavities

Lots of diagnostics

Construction StatusConstruction Status

• Injection line: completed in March

• Ring: “completed” 18th June 2010

22nd June 2010

CommissioningCommissioning

EMMA ring - “completed” on 18th June 2010- start-up: 20th June- ring complete: end of July 2010- 1st commissioning period: Aug to Oct

11stst Commissioning Commissioning

First Turn

Second Turn

16th August 201015 MeV Beam

Magnets set for 18 MeV

24th August 201012 MeV Beam

Magnets set for 18 MeVNo RF

AccelerationAcceleration

• Demonstrating accel. in FF machine not so easy!

• Need to look for orbit changes:- ToF- Tune

• Some evidence obtained before Oct shutdown, but:

AccelerationAcceleration• During Oct-Feb shutdown: - some ring magnets re-aligned - some BPM readout improved - extraction line completed

22ndnd Commissioning Period Commissioning Period

• Real energy: 12 MeV

• Measurements at equivalent

Time of flightTunes

Mean positions

AccelerationAcceleration

Longitudinal phase

Tunes

Beam positions

Extraction lineExtraction line

No RFSeptum = 12

MeV

With RF Septum = 20.2

MeV

ResonancesResonances

• During acceleration:- both horizontal and vertical cell tunes change

by > 0.1 - ring tune changes > 4.2 - 4 integer tunes crossed

The σ of beam orbit oscillations

ConclusionsConclusions

• EMMA is the proof-of-principle non-scaling FFAG

• Construction was a challenge - novel machine - very compact: “…everything takes 5 times longer in EMMA…”, Neil Bliss, project manager

• Commissioning has been successful: - EMMA works! - Beam accelerated from 12 to 18 MeV/c in 6 turns - Small orbit excursion ~10 mm - Many resonances crossed, no observable growth in beam oscillation amplitude

• Long way to go: full experimental programme just started

• Upgrades planned:- improve EMMA performance -

learn more for applications

• EMMA is a great success and would not exist without ASTeC!