the emma project rob edgecock stfc rutherford appleton laboratory & huddersfield university
TRANSCRIPT
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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~ cyclotron
Strongly focussed
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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
27
14
8
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!