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
• 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
Organization / management
Accelerator & Fusion Research Division
Center for Beam Physics
J. Corlett
ES&H
Coordinator
S. Lidia
Initiatives/Projects
Business
Manager
G. Rogers
Groups
Beam Theory
A. Wolski
Beam Electrodynamics
J. Byrd
Future Light Sources
Collider Physics
J. Corlett
M. Zisman
Accl. Modeling &
Adv. Computing
R. Ryne
ILC
M. Furman
CBP staff
Scientific
Engineers
Byrd
Corlett
DeSantis
Fawley
Furman
Beche
Ratti
Virostek
Wilcox
Huang
Li
Lidia
Technical support
Penn
Pogorelov
Qiang
Reichel
Ryne
Venturini
Wolski
Lozano
GSRAs
Bertsche
Chapman
Charman
Goradze
Lindberg
Vogel
Faculty
Fajans
Wurtele
Correa
Gomberoff
Duetsch
Pianetti
Retirees
Commins
Garren
Goldberg
Lambertson
Sessler
Staples
Turner
Voelker
Administrative
Zholents
Zisman
Zolotorev
Visitors
Students
Bates
Burke
Gullans
Ko
Speed
Vinokurov
A'Hearn
Gallant
Rogers
Wong
~50 headcount
~25 FTE
CBP FY06 anticipated funding
Center for Beam Physics has long history of driving tools for
accelerator science
 = HEP AARD activity
 Early SSC beam dynamics
• Original ALS concept and design
 Two-beam accelerator development and design
• Concept of beam conditioning
 First study and design of the asymmetric e+e– collider
 Initial PEP-II positron ring design
 Broad-band, high-gain, multi-bunch feedback systems
 “Monochromatic” damped RF cavity design
 Concept of optical stochastic cooling and proposed tests at RHIC
• Forefront FEL theoretical and numerical research
• Concepts for optical manipulation of electron beams
 Design and evaluation of NLC - now ILC - damping rings
 Early original contributions to g-g collider, m-collider and n-factory
designs
 Essential 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 measurement
 Collective effects analysis
 Electron cloud modeling and benchmarking of codes
• Concept and design of LUX ultrafast light source
• Concept of ultra-bright electron source
 Optimized RF structures for ionization cooling schemes
• Ultra-stable optical timing and synchronization systems
• High-brightness, high-power RF gun design
 Dipole mode “crab” cavity design
 Optical diagnostics for high-energy hadron machines
 Coherent synchrotron radiation (CSR) diagnostics
 Advanced computing and highly-parallelized modeling codes
 Essential development of algorithms for modeling long-range beambeam & cathode image effects
 Support for Tevatron and PEP-II luminosity improvements
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
dE
dx
dE
dx
dE
dx
• “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)
QuickTime™ and a
TIFF (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
• Highly damped dipole mode
superconducting cavities
• Maintain cylindrical symmetry for
ease of production
Concept - unwanted modes are
heavily damped in waveguide
Multi-bunch feedback systems - essential technology for
control of high intensity beams e.g. ILC damping rings
Feedback kickers installed at PEP-II
• Bunch-by-bunch feedback
systems control coupledbunch instabilities
• Highly successful
implementation in PEP-II
and ALS
PEP-II
TRANSVERSE COUPLED BUNCH
FEEDBACK
• Upgrades for PEP-II
implemented
vertical kicker
horizontal kicker
beam
pick-up 2
power
amplifi ers
pick-up 1
D
C
DA C
B
A
vertical
processing
d elay
H2
AD C
receiver
2
V2
B PF
1.5 GHz

C2
variabl e
attenuators
horizontal
p osition
H1





V2 V1
C1

3xRF



receiver
1
L PF
vertical
p osition
V1
• FPGA technology
• Instability studies initiated
Expertise in instrumentation led to LARP support - LHC
Luminosity Monitor
The challenge:
• High radiation environment (100
MGy/year)
• Real-time diagnostic with bunch-bybunch 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
15
22 nsec
10
Signal (mV)
5
0
-5
Measured pulse response
-10
-15
-20mV
58 0
60 0
62 0
64 0
66 0
9 cm
Time (nsec)
68 0ns
Application of expertise in optical diagnostics for proton
machines - Tevatron, LHC
• 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
0.1
0.09
Bunch 1
Bunch 36
0.08
End of Abort Gap 3
0.07
0.06
0.05
0.04
Microbunches are clearly visible.
Diffusion process under study.
0.03
0.02
0.01
0
Gated MCP-PMT
0
50
100
150
200
Time (2ns)
bins (2 ns)
250
300
350
400
Application of expertise in optical diagnostics for proton
machines - Tevatron, LHC
• 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
0.1
0.09
Bunch 1
Bunch 36
0.08
End of Abort Gap 3
0.07
0.06
0.05
0.04
Microbunches are clearly visible.
Diffusion process under study.
0.03
0.02
0.01
0
Gated MCP-PMT
0
50
100
150
200
Time (2ns)
bins (2 ns)
250
300
350
400
Core expertise enabled LBNL to respond to Tevatron
luminosity improvement studies - antiproton beam dynamics
• 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
x, y phase space at end of AP2
Optical stochastic cooling - potential for technology for
proton cooling
RHIC parameters: 1hr
horizontal and longitudinal
cooling time for gold beam
requires 16 W of power
l = 12 µm
Bandwidth ~ 3 THz
LDRD test at BNL ATF for
Optical Parametric Amplification
Beam
p
s
Optical amplifier is based
on 3.5 cm CdGeAs2 crystal
with d14=236 pV/m
i = p - s; kp = ks + ki
p
s
Amplified signal
Pump laser
Developments at RHIC,
e-
cooling proposal at MIT-Bates
Freshly grown crystals at
Lockheed Sanders, NH
NLC damping rings - LBNL responsibility for critical system
for linear colliders
•
•
•
•
•
•
Lattice design
Beam dynamics
RF
Impedance
Collective effects
…
Growth
rate
s-1 1000
4
356
2
355
6
4
2
100
6
4
2
10
0
50
100
150
200
250
Coupled bunch mode number
300
350
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 coupledbunch 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
1 LHC FODO cell
FB B BDB B B
beam
electrons
beam (scaled 10x)
Adaptive Mesh Refinement
x20,000 speedup
T=2ms
Actual LHC pipe
shape/dimensions
Ongoing R&D - electron cloud simulations comparison with
experiment, collaboration with HIF-VNL group at LBNL
Focus of Current
Gas/Electron Experiments
INJECTOR
MATCHING
SECTION
ELECTROSTATIC
QUADRUPOLES
MAGNETIC
QUADRUPOLES
Current HCX Configuration
FLS(2)
The magnetic section is heavily instrumented
for electron effect studies
GIC (2)
BPM (3)
MA4
Integrated program with theory, simulation, and experimental
facility - address physics issues critical to HEP
+9kV
“Roadmap” for self-consistent modeling
+9kV
+9kV
0V
200mA K+
e-
MA1 (a) MA2 (b) MA3 (c) MA4
WARP-3D
T = 4.65ms
- implemented
- in development
200mA
K+
Suite of codes includes new
advanced algorithms:
New electron mover
•
Beam ions
hit end
plate
x10-100 speedup
Adaptive Mesh Refinement
•
x20,000 speedup on LHC run!
Being benchmarked
against HCX expt. data
Electrons bunching
(a)
experiment
simulation
Oscillations
(b)
(c)
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