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Center for Beam Physics. John Corlett Accelerator and Fusion Research Division Lawrence Berkeley National Laboratory Presented to the AARD Sub-panel meeting Palo Alto, California December 21, 2005. CBP accelerator R&D activities. - PowerPoint PPT Presentation
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Center for Beam Physics
John CorlettAccelerator and Fusion Research Division
Lawrence Berkeley National Laboratory
Presented to the AARD Sub-panel meeting
Palo Alto, California
December 21, 2005
CBP accelerator R&D activities
• CBP provides integrated resources to address accelerator science and technology questions and to extend the limits of performance of accelerators
– Accelerator science– Advanced computing and accelerator modeling– Beam electrodynamics– LBEL experimental laboratory (RF, microwave, lasers)
– An incubator for new concepts and future initiatives
– A history of significant involvement in successful accelerator construction projects (e.g. ALS, PEP-II)
– A foundation for support of existing projects and initiatives (e.g. PEP-II, Tevatron, LHC, LARP, ILC)
• Capable and responsive to HEP needs
Center for Beam Physics
J. Corlett
ES&HCoordinator
S. Lidia
Initiatives/Projects
ILC
A. Wolski
Future Light Sources
J. Corlett
Beam Theory
M. Furman
Accl. Modeling & Adv. Computing
R. Ryne
BusinessManagerG. Rogers
Groups
Beam Electro-dynamics
J. Byrd
Collider Physics
M. Zisman
Organization / management
Accelerator & Fusion Research Division
CBP staff
~50 headcount~25 FTE
CBP FY06 anticipated funding
Early SSC beam dynamics• Original ALS concept and designTwo-beam accelerator development and design• Concept of beam conditioningFirst study and design of the asymmetric e+e– colliderInitial PEP-II positron ring designBroad-band, high-gain, multi-bunch feedback systems“Monochromatic” damped RF cavity designConcept of optical stochastic cooling and proposed tests at RHIC• Forefront FEL theoretical and numerical research• Concepts for optical manipulation of electron beamsDesign and evaluation of NLC - now ILC - damping ringsEarly original contributions to collider, -collider and -factory
designsEssential beam dynamics concepts (Lie map techniques, symplectic
integration, beam-beam and e-cloud dynamics, …)
Center for Beam Physics has long history of driving tools for accelerator science
= HEP AARD activity
Beam impedance calculation and measurementCollective effects analysis Electron cloud modeling and benchmarking of codes• Concept and design of LUX ultrafast light source• Concept of ultra-bright electron sourceOptimized RF structures for ionization cooling schemes• Ultra-stable optical timing and synchronization systems• High-brightness, high-power RF gun designDipole mode “crab” cavity designOptical diagnostics for high-energy hadron machinesCoherent synchrotron radiation (CSR) diagnosticsAdvanced computing and highly-parallelized modeling codesEssential development of algorithms for modeling long-range beam-beam &
cathode image effectsSupport for Tevatron and PEP-II luminosity improvements
Center for Beam Physics has long history of driving tools for accelerator science
= HEP AARD activity
PEP-II damped cavities - essential technology for high intensity storage rings
• R&D in monochromatic RF structures
• Waveguide damping reduces HOM impedance by up to 1000x
Ionization cooling RF R&D - developing concepts for future facilities
• “Pillbox” cavities with high shunt impedance
• Thin Be foil (or grid) structures over large aperture
• Successful tests up to 40 MV/m achieved (805 MHz)
dxdE
dxdE
dxdE
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Hardware for MICE experiment
• LBNL responsibilities• Design and fabrication of
prototype cavity• Design of superconducting
“coupling coil” solenoid• Cooling channel integration
Prototype 201 MHz cavity
Ongoing RF structure R&D - “crab” cavities for colliders, applications in LHC, ILC, Super B-factory
Concept - unwanted modes are heavily damped in
waveguide
• Highly damped dipole mode superconducting cavities
• Maintain cylindrical symmetry for ease of production
D BC A
pick-up 1
pick-up 2
poweramplifiers
horizontal kicker vertical kicker
verticalprocessing
beam
V2 V1
H2
V2
receiver2
C2
variableattenuators
C1
PEP-IITRANSVERSE COUPLED BUNCH FEEDBACK
Σ
Σ
Δ
Δ
Σ
Δ
Σ
BPF1.5 GHz LPF
horizontalposition
1H
verticalposition
1V
3xRF
receiver1
Σ
delay
DAC
ADC
Σ
Σ
Multi-bunch feedback systems - essential technology for control of high intensity beams e.g. ILC damping rings
• Bunch-by-bunch feedback systems control coupled-bunch instabilities
• Highly successful implementation in PEP-II and ALS
• Upgrades for PEP-II implemented • FPGA technology• Instability studies initiated
Feedback kickers installed at PEP-II
Expertise in instrumentation led to LARP support - LHC Luminosity Monitor
The challenge:• High radiation environment (100 MGy/year)• Real-time diagnostic with bunch-by-bunch capability (25 nsec
separation) with 1% resolution
The solution:• Segmented, multi-gap, pressurized ArN2 gas ionization chamber
constructed of rad hard materials
• Prototype built & tested at ALS
• Moving into production
9 cm
Expertise in instrumentation led to LARP support - LHC Luminosity Monitor
The solution:• Segmented, multi-gap, pressurized ArN2
gas ionization chamber constructed of rad hard materials
• Prototype built & tested at ALS
9 cm-20mV
-15
-10
-5
0
5
10
15
Signal (mV)
680ns660640620600580
Time (nsec)
Measured pulse response
22 nsec
Application of expertise in optical diagnostics for proton machines - Tevatron, LHC
0 50 100 150 200 250 300 350 4000
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
0.1
Time (2ns)
Bunch 1 Bunch 36
End of Abort Gap 3
bins (2 ns)
Microbunches are clearly visible. Diffusion process under study.
Gated MCP-PMT
• At TeV energy scales, proton machines start to look more like electron synhcrotrons• Use synchrotron radiation optical diagnostics• Abort gap monitor
- Tested at Tevatron- Explored potential use at LHC
Application of expertise in optical diagnostics for proton machines - Tevatron, LHC
0 50 100 150 200 250 300 350 4000
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
0.1
Time (2ns)
Bunch 1 Bunch 36
End of Abort Gap 3
bins (2 ns)
Microbunches are clearly visible. Diffusion process under study.
Gated MCP-PMT
• At TeV energy scales, proton machines start to look more like electron synhcrotrons• Use synchrotron radiation optical diagnostics• Abort gap monitor
- Tested at Tevatron- Explored potential use at LHC
• AP2 transfer line
– Large beamsize and energy spread
– Only ~1% is antiprotons
• Chromatic & large amplitude effects
– Mismatch between transfer line and debuncher
• Developed lattice to improve proton transmission into debuncher
– sextupoles
– matching
Core expertise enabled LBNL to respond to Tevatron luminosity improvement studies - antiproton beam dynamics
x, y phase space at end of AP2
Optical stochastic cooling - potential for technology for proton cooling
Amplified signal
s
p
Pump laser
i = p - s; kp = ks + ki
Beam
s
p
RHIC parameters: 1hr horizontal and longitudinal cooling time for gold beam requires 16 W of power = 12 µmBandwidth ~ 3 THz
LDRD test at BNL ATF for Optical Parametric Amplification
Optical amplifier is based on 3.5 cm CdGeAs2 crystal with d14=236 pV/m
Freshly grown crystals at Lockheed Sanders, NHDevelopments at RHIC, e- cooling proposal at MIT-Bates
10
2
4
6
100
2
4
6
1000
2
4
350300250200150100500
356
355
Coupled bunch mode number
Gro
wth
ra
te
s-1
NLC damping rings - LBNL responsibility for critical system for linear colliders
0
0.002
0.004
0.006
0.008
0.01
0.012
0.014
0.016
0.018
0.02
-0.004 -0.002 0 0.002 0.004
x /m
y /m
0
0.002
0.004
0.006
0.008
0.01
0.012
0.014
0.016
0.018
0.02
-0.004 -0.002 0 0.002 0.004
x /m
y /m
• Lattice design• Beam dynamics• RF• Impedance• Collective effects • …
ILC damping rings and bunch compressors - baseline configuration intensively developed by LBNL
• Damping rings: lattices and beam dynamics– Continued optimization of lattice designs
– Detailed studies of acceptance limitations (e.g. from wiggler)
– Detailed studies of collective effects (including space-charge, and coupled-bunch instabilities)
– Continued development of software tools for beam dynamics studies in DRs
• Damping rings: technical components and subsystems– Continued investigation of low SEY preparations for preventing electron
cloud
– Development of fast stripline kicker for ATF2 extraction
– Specification of vacuum system components to achieve 0.1 ntorr
– Cost estimates of different DR options, to inform selection of design for CDR
• Bunch compressors– Continued development of multi-stage designs
– Detailed performance evaluation of different BC options
Pioneered the field of Electron Cloud Effect (ECE) simulations and analysis - critical capability
• Initially developed for PEP-II, now applied to many other machines• Code POSINST developed at LBNL and SLAC and tested at APS and
PSR• Continue to be leaders in ECE studies
– the ECE is a possible performance-limiting issue
• Important potential constraint in many machines– Critical work continues
• Relevant to present and future machines (e.g. LHC, ILC, Proton Driver)
– Simulations for LHC and SPS– Evaluate ECE power deposition at LHC– Close contact with CERN
Electron cloud simulations - WARP/POSINT self-consistent 3-D simulation tool
Adaptive Mesh Refinement x20,000 speedup
beam (scaled 10x)
electrons
1 LHC FODO cell
F B B B D B B B
T=2s Actual LHC pipe shape/dimensions
beam
Ongoing R&D - electron cloud simulations comparison with experiment, collaboration with HIF-VNL group at LBNL
The magnetic section is heavily instrumented for electron effect studies
INJECTOR MATCHINGSECTION
ELECTROSTATICQUADRUPOLES
MAGNETICQUADRUPOLES
Focus of CurrentGas/Electron Experiments
MA4
BPM (3)
FLS(2)
GIC (2)
Current HCX Configuration
Integrated program with theory, simulation, and experimental facility - address physics issues critical to HEP
Suite of codes includes new advanced algorithms:New electron mover
• x10-100 speedup
Adaptive Mesh Refinement • x20,000 speedup on LHC run!
Being benchmarked against HCX expt. data
WARP-3DT = 4.65s
OscillationsElectrons bunching
Beam ions hit end plate
- implemented - in development
experimentsimulation
(a) (b) (c)
e-
+9kV +9kV +9kV 0V
MA4MA3MA2MA1
200mA K+
(a) (b) (c)
“Roadmap” for self-consistent modeling
200mA K+
AMAC activities support HEP priorities
• Modeling beam-beam effects in Tevatron
• Modeling strong-strong beam-beam effects in LHC
• Collaboration to model FNAL booster
• NLC damping ring design using MaryLie to simulate beam dynamics in wiggler magnets
• ILC damping ring design using MaryLie/Impact to study space charge effects
• Simulations in support of l’OASIS experiments
SciDAC presentation
by Rob Ryne
CBP AARD activities - summary
AARD activities in CBP meet critical needs of HEP
– CBP provides an incubator for major developments and new concepts
– Multi-disciplinary expertise • Accelerator physics and theory• Advanced computing for accelerator modeling• Beam electrodynamics
– Resources• LBEL experimental laboratory
HEP accelerator R&D funding is core to maintaining expertise
A broad R&D program provides HEP with high-value development of science and technologies for application in short (30%), medium (50%),
and long-range (20%) plans
– Expertise developed in medium and long-range R&D allows CBP to respond to short-term needs
– Foundation for support of existing projects and for future initiatives critical to HEP