M W Poole FFAG Workshop Sept 2011
History and Challenges of Particle Accelerators
Mike Poole
ASTeC
M W Poole FFAG Workshop Sept 2011
Birth of Particle Physics and Accelerators
1898 Discovery of radium (α, β, γ) 7.6 MeV
1909 Geiger/Marsden MeV α backscattering - Manchester 1927 Rutherford demands accelerator development Particle accelerator studies start - Cavendish
1929 Cockcroft and Walton start high voltage experiments
1932 The prize achieved: Cockcroft + Walton split Li !!!!
‘High’ voltage generation – brute force UK grid initiated (132 kV) and industrial base started
M W Poole FFAG Workshop Sept 2011
Walton, Rutherford, Cockcroft - 1932
Start of the modern era – particle accelerators
NOBEL PRIZE !
M W Poole FFAG Workshop Sept 2011
Cockcroft-Walton Generator
ISIS
665 kV
Removed 2005 Greinacher 1921
View remains in Cockcroft Institute atrium at Daresbury !
First example of commercial exploitation distraction !
M W Poole FFAG Workshop Sept 2011
Early Challenges
High voltage breakdown
Reliable vacuum systems
Low beam currents
Zero diagnostics
Small industrial base
Scale – big science emerges !
M W Poole FFAG Workshop Sept 2011
Electrostatic Accelerators
1927 Tuve builds multi-MV Tesla transformers
1931 van der Graaff pioneers effective electrostatic solution (1 MeV)
1961 6 MeV machine at Liverpool (Manchester collaboration)
1972 Design Study of 20-30 MV facility at Daresbury
1974 Civil construction starts
1983 NSF commissioned 1992 Closure
M W Poole FFAG Workshop Sept 2011
Daresbury Nuclear Structure Facility (NSF)
Last of the line !
Tandem World high energy: 20+ MV
Control of HV breakdown
Scale: weight/stresses cost ion sources controls environment
M W Poole FFAG Workshop Sept 2011
Resonant Accelerator Concept - LINAC
Wideroe – 1928
Alvarez - 1946
Original CERN linac - 1958
Drift tubes screen beam Synchronism and bunching
M W Poole FFAG Workshop Sept 2011
Linac Challenges
Development of RF power sources – energy limit
Beam dynamics - radial fields at gaps
First use of quadrupoles ?
Permanent magnet solutions
Scaling issues (only few MeV/m)
FQUADs (shown) focus the beam horizontally
DQUADs (as above, rotated 90º) focus vertically
M W Poole FFAG Workshop Sept 2011
Recirculation Concept – The Cyclotron
Radio frequency alternating voltage
Hollow metal drift tubes
time t =0
time t =½ RF period
Automatic Synchronisation
D-shaped RF cavities
Orbit radius increases with energy
Expensive/impractical for high energies (1 GeV)
Lawrence (1932): 4” – 80 keV 11” - 1.2 MeV
q v B = mv2 / r r = mv / qB T = 2πm / qB
M W Poole FFAG Workshop Sept 2011
Accelerator Developments
High energy Cyclotrons have huge magnets - spiral orbits
Also problem of relativistic mass increase: desynchronises (some help from FM synchrocyclotron)
Solution:
Raise magnetic field strength as particle energy increases
Produces annular orbit geometry
SYNCHROTRON
M W Poole FFAG Workshop Sept 2011
Synchrotron Ring Schematic
Focusing magnets
Vacuum tube
Accelerating cavity
Bending magnets
Bending and focussing often combined
M W Poole FFAG Workshop Sept 2011
Early (UK) History
(Synchro)Cyclotrons Berkeley (Lawrence) 60” 20 MeV (1939) Liverpool 37” 20 MeV (1939) Harwell 110” 175 MeV (1949) Liverpool 156” 380 MeV (1954) (extraction)
Linacs
Harwell 3.5 MeV (1947) 15 (Mullard), 55 (Met Vickers), 136 MeV
Synchrotrons Woolwich Arsenal - Goward & Barnes e 8 MeV (1946) (Betatron 1943) Malvern 30 MeV e (1950) Oxford 125 MeV e (1952) Birmingham 1 GeV p (1953) Glasgow 350 MeV e (1954) NIMROD RAL 7 GeV p (1960) NINA DL 5 GeV e (1966)
Clatterbridge Oncology Centre 65 MeV
NINA
M W Poole FFAG Workshop Sept 2011
Origins of Daresbury Laboratory
Particle physics facility
State of art electron synchrotron: 5.3 GeV
Designed 1962 and commissioned 1966 Closed 1977 (all domestic HEP ends)
But not the end of Daresbury !
M W Poole FFAG Workshop Sept 2011
Properties of Charged Particle Beams
Unstable behaviour first encountered by Lawrence
Restoring forces provided by radial magnetic field variation (shims)
Uncoupled transverse motion with periodic driving terms
Hamiltonian solutions - now rare (simulations) canonical x,p
Betatron oscillations occur (tunes Qx/Qy) – and dispersion function
Weak focussing replaced by strong focussing (Q >> 1) => resonances
Phase space area = emittance Lattice functions
Ensemble of particles
M W Poole FFAG Workshop Sept 2011
Simple Accelerator Lattice
Dipole
F Quadrupole D Quadrupole
FODO Cell
Challenge: finite dispersion
M W Poole FFAG Workshop Sept 2011
Modern Double Bend Achromat Cell
Dipole
Quadrupoles
Sextupoles
Dipole Quadrupole
Dispersive Path
Dipole
Non - Dispersive
Model by matrix element procedure (can add perturbations)
M W Poole FFAG Workshop Sept 2011
Storage Rings
Synchrotrons can store beams at required (final) energy
Very high beam currents can be accumulated
Beam lifetime set by: Instabilities gas scattering IBS beam-beam etc Typically 10-50 hours (1012 turns !!!)
Radiation damping benefits electron rings
Exotic cooling schemes needed for protons (and ions)
M W Poole FFAG Workshop Sept 2011
Errors and Nonlinearities
Real accelerators are non-ideal
Misalignments and field errors must be corrected
Nonlinear behaviour must be controlled (fields and motion)
Implies diagnostics and magnetic correctors
Simulated behaviour is crucial – complex analysis
M W Poole FFAG Workshop Sept 2011
Example - Chromatic Correction
Sextupoles – compensate off-energy particle tune shift
Located in finite dispersion region: focussing varies with energy offset
M W Poole FFAG Workshop Sept 2011
Collapse of Dynamic Stability
No sextupoles Corrected to zero chromaticity by single magnet family
Four families Eight families
M W Poole FFAG Workshop Sept 2011
Engineering Challenges
Definition of beam stay clear aperture around a ring
Allocations for oscillations, closed orbit errors, injection, ....
Vacuum chamber walls and alignment (maybe bake out)
Mass component production issues
Radiation hardness
Controls engineering: multi-parameter optimisation
Reliability
M W Poole FFAG Workshop Sept 2011 Cockcroft Education Lectures
Accelerator Technologies
Sources - electron guns photoinjectors, ion sources, ……..
Magnets - EM / SCM / PM DC / AC / Pulsed Harmonic / Periodic Power supplies
RF System - structures power sources Vacuum - UHV modelling diagnostics pumping
Diagnostics - fast high precision non-interactive
Geodesics - alignment feedback
Radiation - losses shielding personnel safety
Dumps - spallation targets collimators
Engineering - mechanical electrical civil
Controls - advanced process control NB Multi-disciplinary teams Resources: construction/operation
M W Poole FFAG Workshop Sept 2011
Accelerator Physics Topics
• Classical electrodynamics - Maxwell (mainly !) • Lorentz forces: Deflection and acceleration
• Single particle dynamics • transport, stability, nonlinear dynamics - tracking & differential algebra
• Multi-particle dynamics • collective effects, wake fields, space charge, coherent instabilities
Production Transport Injection Acceleration Extraction Manipulation Delivery
Analytic modelling + Computer simulation (Start-to-End) (Major code development)
Experimental verification (Commissioning !)
fs nm
M W Poole FFAG Workshop Sept 2011
Summary - Types of Accelerator
Linear Accelerators (Linacs) Multi-cell concepts TW and SW
Cyclotrons Low energy limit
Synchrocyclotrons RF variation compensates mass change – extends energy reach
Betatrons Beam is ‘secondary’ of a transformer - magnetic field limit
Synchrotrons and Storage Rings Ramped magnetic field matches energy – annular design
Other variants Particle sources Microtron RFQ FFAG Plasma wake etc
M W Poole FFAG Workshop Sept 2011
Energy Frontier - Protons
Energy limited by dipole magnetic field strength – ring size
Challenge of superconducting technology
NbTi cable – invented in UK
Critical field limits (short sample sets)
NbSn alternative too difficult (so far)
Tevatron pioneer (1987): 770 dipoles at 4.2T for 1 TeV beams
LHC now operating at 4.2 T (3.5 TeV) but 8.4 T design
Huge cryogenic systems (10’s kW at 4 K, kl/h)
M W Poole FFAG Workshop Sept 2011
Energy Frontier - Electrons Limited by radiation emission (accelerated charge)
Technology and electricity costs
Properties calculated since 1897 (Larmor)
Lienard and Schott studied relativistic particles on circular trajectories:
P α E4/R2 So this applies to accelerated beams of charged particles in
a ring (synchrotron)
SYNCHROTRON RADIATION
=> Severe losses and energy restrictions GE synchotron 1947
M W Poole FFAG Workshop Sept 2011
LEP Technical Challenges
3280 revolutionary low field concrete magnets (0.1 T) !
27 km machine
3% energy loss per turn (at 100 GeV)
20MW synchrotron radiation
Superconducting RF systems
Nb coated Cu structures 288 cavities total
M W Poole FFAG Workshop Sept 2011
Superconducting RF Technology
Slower to be adopted than superconducting magnets
Serious technical challenges
Power saving is only one issue
Structure quality reduces (some) beam instabilities
Tuning challenges (Q ~ 106) – and microphonics
J-lab module
Power coupler
Avoid dust and other contaminants
New surface treatments – complex processing
Class 10 clean rooms
M W Poole FFAG Workshop Sept 2011
Unexpected Challenges - Tides and TGV !!!!
Influence on the beam energy moon, sun and tides level of lake Geneva rainfall
AND the fast train.........
5 A induced in the vacuum chamber
M W Poole FFAG Workshop Sept 2011
LHC Accelerator Complex
7 TeV x 2
M W Poole FFAG Workshop Sept 2011
LHC: Some Parameter Challenges
1612 different electrical circuits 8 Sector Powering Circuit
1220 Magnet Stored Energy (MJoules)
1MJ melts 2kg Cu 370 Beam Stored Energy ( MJoules)
2.2.10-6 loss causes quench 0.5 Beam Intensity (A)
1ppm resolution 13000 Current in dipole sc coils (A)
Super-fluid helium 1.9 Operating Temperature (K)
8.4 Dipole Field Strength (Tesla)
14.3 Length of Dipole (m)
Cable Nb-Ti, cold mass 37million kg 1232 Number of Dipoles
100-150m underground 26.7 Circumference (km)
M W Poole FFAG Workshop Sept 2011
LHC Construction and Repair
20 per week
Sept 2008
Beam Screen (BS) : The red color is characteristic of a clean copper
surface
BS with some contamination by super-isolation (MLI multi layer
insulation)
BS with soot contamination. The grey color varies depending on the thickness of the soot, from grey to
dark.
53 magnets removed
Major cleaning/inspection
M W Poole FFAG Workshop Sept 2011
LHC Update
Restarted November 2009 (450 GeV injection)
Collisions at 3.5 x 3.5 TeV in March 2010
Further shutdown at least one year (2013 +)
Major beam dynamics challenges – luminosity
Full energy (7 TeV) by 2014 but full specification
2016 ?
LHC upgrade programme under review (inc LHeC)
M W Poole FFAG Workshop Sept 2011
Next Generation HEP Facility
LEP
SLC
ILC
CLIC
1.E+30
1.E+31
1.E+32
1.E+33
1.E+34
1.E+35
0 1 2 3 4 5
Energy (TeV)
Lum
inos
ity (c
m-2
sec
-1)
main linacbunchcompressor
dampingring
source
pre-accelerator
collimation
final focus
IP
extraction& dump
KeV
few GeV
few GeVfew GeV
250-500 GeV
TeV Electron Linear Collider
SLC
M W Poole FFAG Workshop Sept 2011
Configuration for 500 GeV machine (C of M) Expandability to 1 TeV
Early ILC Baseline Concepts
M W Poole FFAG Workshop Sept 2011
ILC Beam Parameters
• Electrons/bunch 0.75 10**10
• Bunches/train 2820
• Train repetition rate 5 Hz
• Bunch separation 308 ns
• Train length 868 µs
• Horizontal IP beam size 655 nm
• Vertical IP beam size 6 nm
• Longitudinal IP beam size 300 µm
• Luminosity 2 10**34
Challenges on precision collisions !
M W Poole FFAG Workshop Sept 2011
ILC - Main Linac R&D
Total of 1680 cryomodules and 14 560 SC RF cavities
~1m 9 cell 1.3 GHz Nb cavity
Novel fabrication techniques Eg spinning, hydroforming
Chemical Polish
Electro Polish Mass production challenge
M W Poole FFAG Workshop Sept 2011
0
500
1,000
1,500
2,000
2,500
3,000
3,500
4,000
4,500
MainLinac
DR RTML e+Source
BDS Common Exp Hall e-Source
VA
LUE
- $M
ILC Greatest Challenge ?
Conventional Facilities Components
2007 Cost Estimate: 6.7 B$ + labour = 8 B$
This means a major design push to reduce costs, or .............
M W Poole FFAG Workshop Sept 2011 Global Design Effort 40
ILC Design Updates
RDR SB2009
Centralised region (e+ included) Single tunnel Smaller DR
M W Poole FFAG Workshop Sept 2011
CLIC MODULE
Drive beam - 150 A, 130 ns from 2 GeV to 200 MeV
Main beam - 1 A, 100 ns from 9 GeV to 1.5 TeV
QUAD
QUAD
POWER EXTRACTION STRUCTURE
30 GHz - 230 MW
BPM
ACCELERATING STRUCTURES
(6000 modules/linac at 3 TeV)
CLIC Alternative: ‘Two Beam’ Accelerator
30 GHz design now abandoned Moved to 11-12 GHz
0 0.5 1 1.5 2 2.5 3
x 106
0
50
100
150
200
No. of shots
Peak
Acc
eler
atin
g fie
ld (M
V/m
)
3.5 mm tungsten iris3.5 mm tungsten iris after ventilation3.5 mm copper structure3.5 mm molybdenum structureCLIC goal loadedCLIC goal unloaded
World record 150 MeV/m
M W Poole FFAG Workshop Sept 2011
Plasma Wake Accelerators ?
79 80 81 82 83 84 85 86 87 88 89 90 91
0.0
0.5
1.0
Num
ber o
f ele
ctro
ns /
MeV
[a.u
.]
Energy [MeV]
laser
self-injected electron bunch undergoing betatron oscillations
ion bubble 0.8%γσ
γ=
In principle 100 GeV/m
33 mm plasma channels
Berkeley: 1 GeV achieved
Radiation source demonstrations
Strathclyde
Big Lasers !!
M W Poole FFAG Workshop Sept 2011
PETRA-III
2-d scanning system
Vertical
my µσ 2.08.1 ±=mx µσ 2058 ±=
KEK ATF
Courtesy: G Blair and RHUL group
Micron Scale Beam Diagnostics 532 nm
“Laser Wire”
M W Poole FFAG Workshop Sept 2011
Advanced Radiation Sources
Electron
Cone angle = 1/γ
Acceleration
Parasitic use on HEP facilities - 1st Generation
Daresbury SRS - 2nd Generation (1981-2008)
1E+05
1E+06
1E+07
1E+08
1E+09
1E+10
1E+11
1E+12
1E+13
0.0001 0.001 0.01 0.1 1 10 100ω/ωc
Spec
tral
Pho
ton
Flux
(pho
tons
/s/m
rad/
0.1%
ban
dwid
th/G
eV/1
00m
A
33R4γ
≈λc
R
For 2 GeV, 1.2 T:
R ~ 5.5 m, γ ~ 4000
Wavelength ~ 0.1 nm
M W Poole FFAG Workshop Sept 2011
Compact Light Sources
Demand is high for access to Light Sources
National facility scale dominates landscape
Alternatives include example of HELIOS (700MeV)
Commissioned 1991 (OI/Daresbury)
IBM operated for lithography trials
Superconducting magnets (4.5 T)
M W Poole FFAG Workshop Sept 2011
High Field Insertion Devices
1.0E+10
1.0E+11
1.0E+12
1.0E+13
1.0E+14
1.0 10.0 100.0 1000.0 10000.0 100000.0
Photon Energy (eV)Sp
ectr
al P
hoto
n Fl
ux(p
hoto
ns/s
/mra
d/0.
1% b
andw
idth
)
1.2 T Magnet6.0 T Magnet
Normal Straight
With Insertion Device
SRS Superconducting Wavelength Shifter 6.0 Tesla
λc ∼ B-1
Challenging design - pole proximities
M W Poole FFAG Workshop Sept 2011
Multiple Pole Emission
λπ
−=u
0s2sinB)s(B
λπ
γ=
λπ
πλ
γ=
uu
u0 s2cosKs2cos2mc
eBdsdx
u0u0 B4.93
2mceBK λ=
πλ
=
λπ
πλ
γ=
u
u s2sin2
Kx
Maximum angle is equal to K/γ
-6
-4
-2
0
2
4
6
8
10
12
-2 -1.5 -1 -0.5 0 0.5 1 1.5 2
Longitudinal Position (m)
Hor
izon
tal P
ositi
on (m
m)
B Fi
eld
(T)
Position
Field
-6
-4
-2
0
2
4
6
-1 -0.5 0 0.5 1
Longitudinal Position (m)
Mag
netic
Fie
ld (T
)
2/γ 2/γ K/γ
K < 1 K >> 1
M W Poole FFAG Workshop Sept 2011
Interference
Electron
d
λu θ
Condition for interference: θλ−βλ
=λ= cosnd us
u
M W Poole FFAG Workshop Sept 2011
Undulator Equation
Substituting in for the average longitudinal velocity of the electron, βs :
++= 22
2
2 21
2γθ
γλλ Kn
u
eg 3 GeV electron and 50 mm period undulator with K = 3:
1st harmonic (n = 1) on axis (θ = 0) is ~ 4 nm
Width ~ 1/nNλ
(cf slit/grating results)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
0 10 20 30 40 50 60Frequency (Arb. Units)
Inte
nsity
(Arb
. Uni
ts)
LN ur
λλ
λσλ
=≈'
eg λ ~ 1nm and L ~ 5m,
σr’ ~ 14 µrad
3GLS Bright Beams
M W Poole FFAG Workshop Sept 2011
Third Generation Light Sources
EmittanceFluxBRIGHTNESS =
3
2
cellNEk=ε
Comparison of 3rd Generation Synchrotrons
Diamond
Swiss Light Source
APS (USA)
PETRA III (Germany)
ESRF
Canadian Light Source
SPring-8 (Japan)
ELETTRA (Italy)
Australian SynchrotronALS (USA)
SOLEIL (France)
SPEAR3 (USA)
BESSY II (Germany)
MAX-II (Sweden)
ALBA/CELLS (Spain)
PLS (Korea)
0
2
4
6
8
10
12
14
16
18
20
0 1 2 3 4 5 6 7 8 9
Energy / GeV
Emitt
ance
/ nm
rad
Diamond Light Source
Incorporate all modern features – and challenges
ESRF Grenoble
M W Poole FFAG Workshop Sept 2011
Challenging Undulator Specifications
Not free choice of periodicity
Period/gap ratio is critical parameter (Maxwell !)
Ratio > 2
Gap set by aperture needs of beam, including tolerances
Periodicity must incorporate coil space (if present)
Permanent magnet systems optimise period and performance
SmCo or NdFeB Remanence ~ 1-1.5 T
M W Poole FFAG Workshop Sept 2011
Solution to the Challenge
λπ−
≈u
0gexp2.2B
g = gap between the two arrays
With only 4 blocks per period the field is very sinusoidal
M W Poole FFAG Workshop Sept 2011
Periodic Magnet Examples
Basis of all modern Light Sources - 3GLS
Very considerable quality challenges: high precision essential - block sorting, construction techniques, measurement, shimming
M W Poole FFAG Workshop Sept 2011
Free Electron Laser (FEL) Principles
cm)in is λ and Teslain is (B periodundulator theis λ
λ0.934BK ,cm
E γ
... 1,2,3n :where
θγ2
K12nγλ λ
u0
u
u020
222
2u
n
==
=
++=
mp
Intensity ~ Ne
Intensity ~ Ne2
4th Generation Light Source Gain α electron beam brightness
M W Poole FFAG Workshop Sept 2011
World Record Oscillator
400
300
200
100
Inte
nsity
(a.u
.)
190.8190.6190.4190.2190.0189.8189.6Wavelength (nm)
λ = 189.9 nmFWHM = 0.06 nm∆λ/λ = 3.1 10-4
Lased at 190 nm in 2001 World record !
300
200
100
0
Pow
er (m
W)
270265260255250245240235Wavelength (nm)
medium T @ 34 mA high T @ 32 mA
350300250200Wavelength (nm)
Wavelength Multilayer mirror type Lasing 350 - 356 nm Ta2O5/SiO2 yes
235 - 265 nm HfO2/ SiO2 yes
218 - 224 nm Al2O3/ SiO2 yes 189.7 - 200.3 nm Al2O3/ SiO2 yes
186 nm LaF3/MgF2 no
Very limited tuning
Sincrotrone Trieste
M W Poole FFAG Workshop Sept 2011
FEL Oscillators - Summary
Infra-red FEL operated 1977 – few sources before 1990
Tunable and high power (octave and kW)
User facilities highly successful (eg FELIX in Nieuwegein)
Short wavelength limited by mirrors
Mainly electron linacs but storage ring versions tried
Next Generation Sources to employ alternative FELs ?
M W Poole FFAG Workshop Sept 2011
Advanced FELs for XUV and X-rays
Major electron accelerators (GeV +)
Remove mirrors - new amplifier regime (demo 1985) Enormous challenges - high brightness beams and kA currents
Particle Physics technologies - Linear Collider synergy
Self Amplified Spontaneous Emission (SASE)
No Mirrors ! Configuration before upgrades
June 2010 achieved 4.5 nm at 1.2 GeV
FLASH Facility
M W Poole FFAG Workshop Sept 2011
γεx,y = 0.4 µm (slice) Ipk = 3.0 kA σE/E = 0.01% (slice)
(25 of 33 undulators installed)
courtesy of P. Emma, SLAC
1.5 Å
New World Record - LCLS 2009
Use of 1/3 SLAC Linac 14 GeV
Linac Coherent Light Source
Electron bunch length < 100 fs !
M W Poole FFAG Workshop Sept 2011
Chirped Bunch Compression
z
sz
δ
z
δ
sz0
δ
z
sE/E
RF Acceleration Bunch Compression
z
sz
δ
z
sz
δ
z
δ
z
δ
sz0
δ
z
sE/E
sz0
δ
z
sE/E
RF Acceleration Bunch Compression
Compress (shorten) bunch to increase peak current (kA => 100 fs) (but at cost of energy spread from chirp)
Time-Energy correlation
M W Poole FFAG Workshop Sept 2011
Ultra-short Pulse Diagnostics
.
Probe laser Optical replica
Non-linear mixing
Coulomb pulse replicated in optical pulse
electron beam
65µm thick GaP
Record results at FLASH (DESY) 100 fs resolution
M W Poole FFAG Workshop Sept 2011
Intensity Frontier
Low energy colliders (eg B-factory)
Proton drivers – spallation sources
Proton driver – Neutrino Factory
Space charge challenge
High power limitations
ISIS - 800 MeV
300 µA
M W Poole FFAG Workshop Sept 2011
High Power Proton Accelerators
590 MeV 2 mA
1.2 MW
PSI Zurich
SNS at Oak Ridge also reaches ~ 1 MW ISIS operates up to 240 kW ESS plans 5 MW
Trip rates / High power proton accelerators
0.01
0.1
1
10
100
1000
0.1 1 10 100 1000 10000 100000 1000000Trip length (seconds)
Trip
s pe
r day
long
er th
an tr
ip le
ngth
ISISLANSCEPSISNS
THOREA Collaboration investigations
232Th233Th233Pa233Ufission Actinides absent Proliferation resistant
Extreme reliability challenge
Challenge: losses < 10-6/m
Spallation sources:
M W Poole FFAG Workshop Sept 2011
Muon
Storage
Ring
High current H– source Proton
Driver Target Capture
Cooling
Muon Acceleration
‘near’ detector (1000–3000km)
‘far’ detector (5000–8000km)
‘local’ detector
Neutrino Factory Concept
M W Poole FFAG Workshop Sept 2011
Neutrino Factory UK Design Studies
Collaboration of 6 HEIs with ASTeC Glasgow IC Liverpool Oxford Sheffield Warwick
Funding also boosted in 2004 – and sustained
Sponsored International Scoping Study and now IDS
Proton drivers and muon accelerators (eg FFAG)
Technology programme
Front End Test Stand Targets RF breakdown studies
MICE FP7 EuroNu Design Studies
M W Poole FFAG Workshop Sept 2011
Baseline Design
10 GeV
M W Poole FFAG Workshop Sept 2011
NF Design Challenges
5-10 MW proton beam generation
Pion target survival
Muon capture and cooling
Muon acceleration and storage
Other applications !
FFAG solution attractive muon accelerator
M W Poole FFAG Workshop Sept 2011
Layout of MICE Experiment
Muon Ionisation Cooling Experiment
ISIS source
Muon beam from ISIS
M W Poole FFAG Workshop Sept 2011
High speed beam chopper & MEBT 324 MHz, 3 MeV RFQ
3 solenoid magnetic LEBT H- ion source 60 mA, 65 keV 2 ms pulse length 50 pps
Front End Test Stand at RAL (FETS)
Demonstration of injector for multi-MW source
RFQ Model - IC
M W Poole FFAG Workshop Sept 2011
Novel Challenge - FFAG Development
Fixed Field Alternating Gradient accelerator
Originally considered 1950’s but ‘rediscovered’
Cyclotron with compressed orbits => a ring
Proposed as muon accelerator – no field ramp necessary
Basic Technology grant for medical development (mainly) - hadron therapy solution ?
Possible HPPA contender too ?
1.3672
1.3671
1.3670
1.3669
1.3668
1.3667
1.3666
201816141210kinetic energy [GeV]
Challenges: Resonances Asynchronous acceleration
M W Poole FFAG Workshop Sept 2011
Chirped beam compression ~100 fs FEL included
‘Green’ machine
ALICE = Accelerators and Lasers in Combined Experiments
ALICE Test Facility at Daresbury
Energy Recovery Linac Prototype
M W Poole FFAG Workshop Sept 2011
EMMA Non-scaling FFAG at Daresbury
Proof of principle demonstrator – world first
Inject beam of electrons from ALICE
Commissioning from 2010
10-20 MeV Low Energy Beam High Energy Beam
No bending magnets ! 42 cells 19 cavities
Circumference 16.7 m
Coasting beam survives 1000 turns
Ring operated 10-20 MeV injection
M W Poole FFAG Workshop Sept 2011
Challenges Successfully Addressed
Natural sources replaced
Ingenuity
Complex beam dynamics analysis
Frontier technologies
Advanced diagnostics and control
Project management and delivery
All will need to be repeated for next generation solutions !
FFAG ???