of high-intensity particle beams from normal- and
TRANSCRIPT
Παραγωγή, διάγνωση και δυναμική
σωματιδιακών δεσμών υψηλής έντασης από
συμβατικούς και υπεραγώγιμους επιταχυντές
Georgios KourkafasINP Demokritos, 22.11.2018
Generation, diagnosis and dynamics
of high-intensity particle beams from
normal- and superconducting accelerators
Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
> Self introduction
> p+ beam dynamics and diagnostics at LHC (CERN, Switzerland)
> e- beam dynamics and diagnostics at PITZ (DESY, Germany)
> e- beam generation and applications at bERLinPro (HZB, Germany)
Outlook
2
Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
> Born in 1986, city of origin: Korinthos, Greece
> Diploma in Electrical and Computer Engineering in 2010 –
National Technical University of Athens, Greece
Focus in Electric Power and Biomedical Engineering
Thesis: Motion tracking in spin-tagging Magnetic Resonance Imaging (MRI)
using the Harmonic Phase (HARP) method. Collaboration with Urbana University, USA
Self Introduction – University education
3
Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
Self Introduction – Further education
4
> 2011: Joint Universities Accelerator School (JUAS), Archamps, France
(Basic Accelerator Physics Theory)
> 2012: Physics Studies at Humboldt University, Berlin, Germany
Theoretical and Experimental Quantum Physics
Nuclear and Elementary Particle Physics
> 2013: CERN Accelerator School (CAS), Trondheim, Norway
(Advanced Accelerator Physics)
> 2014: CERN Accelerator School (CAS), Meyrin, Switzerland
(Plasma Wake Acceleration)
> 2018: CERN Accelerator School (CAS), Thessaloniki, Greece
(Numerical Methods for Analysis, Design and Modelling of Accelerators)
Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
Experience from LHC (CERN)
> Technology Department –
Machine Protection and Electrical Integrity Group –
Performance Evaluation Section
> Technical Student (01.2010 – 02.2011)
> Work summary:
Data analysis, measurements and
calculations for improving LHC
operation and machine protection
Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
> LHC has ~1000 superconducting Corrector Orbit Dipoles (COD), controlled
with an auto-feedback system
> Motivation: estimate the effect of a COD failure during collision optics
> Beam dynamics calculations suggest
a significant vertical misplacement:
> Beam loss is expected due to the failure
Investigations on Orbit Correctors (I)
Collimator TCP.D6L7.B1
Dy (sigma) 7.0
Collimator half gap (sigma)
9.8
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Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
Event evolution
Investigations on Orbit Correctors (I)
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Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
Event evolution
Investigations on Orbit Correctors (I)
with a σ/3 beam offset
8
Beam Position Monitor (BPM) reliability?
Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
> Misbehaving BPMs & unnecessary / undetected orbit bumps are risky!
> How reproducible are the feedback settings of the corrector magnets?
Spot strong differences between consecutive fills:
> Calculate the effect of these single kicks on the beam orbit with MAD –
cross check calculations with BPM readings
Investigations on Orbit Correctors (II)
0.00E+00
2.00E-06
4.00E-06
6.00E-06
8.00E-06
1.00E-05
1.20E-05
0 5000 10000 15000 20000 25000
Dif
fere
nce
in k
ick
(rad
)
Position (m)
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Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
Investigations on Orbit Correctors (II)
-1400
-1200
-1000
-800
-600
-400
-200
0
200
400
600
BPM Readings - Difference between consecutive fills [μm]
Magnet name MCBV.11L1.B1 MCBCV.9L1.B2 MCBCV.7L1.B3
kick [rad] 1.19E-05 0 1.11E-05
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Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
Investigations on Orbit Correctors (II)
> Unwanted closed orbit bumps can be created by the feedback algorithm
> The evolution of the beam orbit might indicate undetected problems…
Magnet name MCBV.11L1.B1 MCBCV.9L1.B2 MCBCV.7L1.B3
kick [rad] (previous slide) 1.19E-05 0 1.11E-05
kick [rad] (closed bump) 9.96E-06 1.23E-06 1.30E-05
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Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
Investigations on Orbit Correctors (II)
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Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
Investigations on Orbit Correctors (II)
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Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
Investigations on Orbit Correctors (II)
14
Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
Investigations on Orbit Correctors (II)
15
Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
Investigations on Orbit Correctors (II)
16
Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
Investigations on Orbit Correctors (II)
17
Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
Investigations on Orbit Correctors (II)
18
Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
Investigations on Orbit Correctors (II)
> A specific orbit corrector magnet was not powered for 5 consecutive fills
> Conclusion: the calculation of the beam orbit from the evolution of the
corrector magnets together with the monitoring of the BPM enhances the
redundancy of the LHC machine protection and optics reproducibility
> Resulted in the development of a software interlock which warns on
potential problems. It was later extended with a machine learning algorithm
-800
-600
-400
-200
0
200
400
600
800
BP
MS
W.1
R1.
B1
BP
M.1
2R
1.B
1B
PM
.24
R1.
B1
BP
M.3
2L
2.B
1B
PM
.20
L2
.B1
BP
M.8
L2
.B1
BP
MW
B.4
R2
.B1
BP
M.1
5R
2.B
1B
PM
.27
R2
.B1
BP
M.2
9L
3.B
1B
PM
.17
L3
.B1
BP
MW
E.5
L3
.B1
BP
M.9
R3
.B1
BP
M.2
1R3
.B1
BP
M.3
3R
3.B
1B
PM
.23
L4
.B1
BP
M.1
1L4
.B1
BP
MY
A.6
R4
.B1
BP
M.1
8R
4.B
1B
PM
.30
R4
.B1
BP
M.2
6L
5.B
1B
PM
.14
L5
.B1
BP
MS
Y.4
L5
.B1
BP
MW
T.B
6R
5.B
1B
PM
.17
R5
.B1
BP
M.2
9R
5.B
1B
PM
.27
L6
.B1
BP
M.1
5L
6.B
1B
PM
SE
.4L
6.B
1B
PM
.14
R6
.B1
BP
M.2
6R
6.B
1B
PM
.30
L7
.B1
BP
M.1
8L
7.B
1B
PM
.6L
7.B
1B
PM
.8R
7.B
1B
PM
.20
R7
.B1
BP
M.3
2R
7.B
1B
PM
.24
L8
.B1
BP
M.1
2L
8.B
1B
PM
SW
.1L
8.B
1B
PM
.11R
8.B
1B
PM
.23
R8
.B1
BP
M.3
3L
1.B
1B
PM
.21L
1.B
1B
PM
.9L
1.B
1
(μm
)
BPM readings – difference between consecutive fills
Dif 1389-1393
Dif 1408-1418
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Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
Experience from PITZ (DESY)
> From high-energy p+ for colliders
to low-energy e- for radiation sources
> PhD Student (06.2011 – 10.2015)
> Work summary:
– space-charge consideration
in the tomographic reconstruction and
the matching of the transverse phase space
– operation of the PITZ facility as shift leader
(conditioning, commissioning, beam diagnostics)
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Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
PITZ facility
7 MeV/c
Bucking solenoid
Main solenoid
Cs2Te
photocathode
RF cavity
laser
beam
e- beam
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> Electron bunches for Free Electron Lasers
2 – 25 ps laser pulses
< 4 nC bunch charge
Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
PITZ facility
> Electron bunches
2 – 25 ps laser pulses
< 4 nC bunch charge
< 25 MeV/c momentum
25 MeV/c
22
Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
PITZ facility
> Electron bunches with high space-charge influence
2 – 25 ps laser pulses
< 4 nC bunch charge
< 25 MeV/c momentum
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Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
PITZ facility
> Electron bunches with high space-charge influence
2 – 25 ps laser pulses
< 4 nC bunch charge
< 25 MeV/c momentum
> Several diagnostics for the longitudinal and transverse phase space:
3 slit-scan stations (EMSYs) and 1 phase space tomography [PST] module
24
Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
PITZ facility
> Electron bunches with high space-charge influence
2 – 25 ps laser pulses
< 4 nC bunch charge
< 25 MeV/c momentum
> Several diagnostics for the longitudinal and transverse phase space:
3 slit-scan stations (EMSYs) and 1 phase space tomography [PST] module
> Various applications require transverse beam matching. Due to the constantly
changing machine parameters (test facility), fast solutions are needed
25
Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
+ Improved SNR
(→ suitable for low charges)
+ Simultaneous measurement of x-x’ & y-y’
(→ less sensitive to short-term machine instabilities)
− Requires beam matching and space-charge treatment
for optimal performance
Transverse Phase Space Tomography
linear
transport
matrices
beam
profile
monitors
> Tomography: algorithmic reconstruction of a sample
from its projections at different orientations
26
Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
Beam tomography & matching with space charge
> Beamline components:
1. Quadrupoles apply phase-space transformations
between the projection screens [1..4]
> Matching requirements // strategies:
1. equidistant phase advance values (45º)
@ each screen (∝ rotation angles) // extend
MAD by scaling beam parameters with
smooth-approximation space-charge theory
2. Courant-Snyder parameters @ screen [1] →
βx,y = 1 m, αx,y = ±1
M2
M3
M4
S N
N S
gives instant result,
eliminates < 38°
mismatch
27
Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
> Beamline components:
1. Quadrupoles apply phase-space transformations
between the projection screens [1..4]
2. Matching quadrupoles for the necessary
entrance beam parameters
> Matching requirements // strategies:
1. equidistant phase advance values (45º)
@ each screen (∝ rotation angles) // extend
MAD by scaling beam parameters with
smooth-approximation space-charge theory
2. Courant-Snyder parameters @ screen [1] →
βx,y = 1 m, αx,y = ±1 // SC software (HZB) to
match and compensate emittance growth…
Beam tomography & matching with space charge
28
Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
(~15 min) / 500 pC, 21 MeV/c, 12 ps \ (~3.5 h)
Beam matching with space charge:
simulation benchmarking
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Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
Beginning of matching (slit scan)
Beam matching with space charge:
simulation & measurement
X
Y
Simulated Measured
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Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
2 m downstream, 4 quads in between (slit scan)
Beam matching with space charge:
simulation & measurement
X
Y
Simulated Measured
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Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
Beam matching & tomography with space charge:
simulation & measurement8 m downstream, 9 quads in between (tomography)
X
Y
Simulated Measured
> Tomographic
reconstruction
corrected by
< 20%
> Applicable to
compression
regions of
FELs,
plasma wake
acceleration,
injection lines
(EMMA), etc.
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Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
Experience from bERLinPro (HZB)
> From conventional to state-of-the-art technologies
> Postdoc (10.2015 – present)
> Institute for Accelerator Physics –
High Brightness Electron Beams Group
> Work summary:
- SRF photoinjector operation and coordination
- procurement of new hardware components
- feasibility studies of ultrafast electron diffraction
33
Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
Max. beam energy (MeV) 50
Max. beam current (mA) 100 (77 pC / bunch)
Frequency (GHz) 1.3
Norm. emittance (mm∙mrad) 1 (< 0.5 in simulations)
Bunch length (ps) < 2 ps (100 fs)
Beam losses << 10-5 @ 100 mA
SRF Photoinjector
• CsK2Sb photocathode
• 515 nm laser, CW operation
• 1.4-cell SRF cavity (klystron)
• ΔE = 2 MeV
• SC solenoid
Merger section
• Injection to LINAC
• Bunch compression
• Emittance compensation
Main LINAC
• 3 × 7-cell SRF cavities (SSA)
• ΔE = 44 MeV
• Energy recovery
Splitter section
• Extracts decelerated beam
• Static widening, dynamic
sweep
Booster module
• 3 × 2-cell SRF cavities,
1 for RF chirp (SSA)
2 for acceleration (klystrons)
• ΔE = 4 MeV
Diagnostic line
Beam dump
bERLinPro: combine advantages of storage rings (high current) and linacs (low emittance) in
a power-efficient (100% duty cycle) small-scale accelerator
Recirculator
• TBA arcs for high
transmission and
tunability
Berlin Energy Recovery Linac Prototype
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Phase
V
Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
Photocathodetransfer system
SRF injector
Laser input
Diagnostic beamline
Superconducting RF photoinjector test stand
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Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
bERLinPro photoinjector characterization
Schottky scans Momentum scan at 10.2 MV/m
QE at 9.5 MV/me- beam measurements with:
• Cu cathode, 1.8 mm laser spot diameter
• UV laser with 12 kHz repetition rate
and 0.7 ps rms Gaussian pulses
• < 10 MV/m acceleration gradients
• measured properties: up to 1 nA current
(100 fC charge) and 1.2 MeV/c momentum
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Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
Superconducting solenoid magnet
Superconducting solenoid upgrade achieved:
• focusing properties for emittance compensation
• thermal conduction
• electrical insulation
• mounting complexity
Sophisticated 6D positioning with a hexapod,
beam based alignment with genetic optimizer
Manufactured by external
company – designed, tested
and measuremented at HZB
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Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
Transverse deflecting RF cavity
Tool for longitudinal beam diagnostics:
• bunch duration
• longitudinal phase space
• transverse slice emittance
Modified Cornel design manufactured
by external company, tested &
conditioned at HZB, installed at bERLinPro
y
z
e-
E-field
38
Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
Ultrafast electron diffraction / microscopy
Material research with fs-short MeV e- which probe samples at MHz rates
• motivation: examine time-resolved
structural dynamics of surfaces, thin films,
biological & gas-phase samples
Feasibility study for HZB: beam dynamics and
collimation, samples, detector
39
Sample DetectorAdditions Collimator
SRF injector
Existing systems
Emittance
scanner
transverse
deflectorSpectro
meter
quads
z [m]
Bea
m s
ize
[mm
]
Cou
rte
sy
E.
Pa
no
fski
< 100 eV uncorrelated
energy spread
10 fC – 2 MeV
9 Å coherence
length 85 fs
bunch duration
60 μm·rad
transverse emittance
60nm WS2 on 500um Cu
Georgios Kourkafas | 22.11.2018Generation, diagnosis and dynamics of high-intensity particle beams from normal- and superconducting accelerators
Summary & outlook
> From high-energy p+ colliders to low-energy e- sources,
accelerators require rigorous design, simulation, diagnostics,
characterization and machine protection to achieve optimal performance
> Range of applications expand constantly to new areas in
fundamental and material research
medical and industrial fields
> Interest tends to shift from large-scale facilities to small, cost-effective
machines: compact radiation sources, plasma wake acceleration,
ultrafast electron diffraction & microscopy, …
> Accelerators: “Extraordinary Tools for Extraordinary Science”!
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THANK YOU FOR
YOUR ATTENTION
Achnowledgments:
CERN: R. Schmidt, M. Koratzinos
Cockcroft Institute: Kai M. Hock
Fritz Haber Institute: R. Ernstorfer, D. Zahn
DESY Zeuthen group: M. Krasilnikov, D. Malyutin, G. Vashchenko, F. Stephan
DESY Hamburg: M. Dohlus, B. Marchetti, J. Rossbach
HZB bERLinPro group: A. Matveenko, J.-H. Gwang, A. Jankowiak, T. Kamps,
G. Klemz, J. Kühn, A. Neumann, E. Panofski, M. Schmeißer, J. Völker
… and many more people which is difficult to include in one slide