Beam Dynamics Codes: Availability, Sophistication, Limitations … P.N. Ostroumov and B. Mustapha Argonne National Laboratory J.-P. Carneiro Fermi National Accelerator Laboratory ESS Bilbao Initiative Workshop March 16-18, 2009 Bilbao, Spain
May 31, 2015
Beam Dynamics Codes: Availability, Sophistication,
Limitations …
P.N. Ostroumov and B. Mustapha
Argonne National Laboratory
J.-P. Carneiro
Fermi National Accelerator Laboratory
ESS Bilbao Initiative WorkshopMarch 16-18, 2009
Bilbao, Spain
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov 2
Outline
Beam Dynamics Codes: History and Evolution
General Comments: Codes Availability, Sophistication, Limitations
Comparing Codes to Measurements: An example
Our Side of the Story: Comparing TRACK to few other Codes
Summary & Recommendations to the Users
Presentation of TRACK, If interested- General Presentation - Sample TRACK Applications- Recent & Future Developments
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov 3
Beam Dynamics Codes: History (From R. Ryne’s Talk at HB-2008 Workshop)
1970 1980 1990Transport
2000
MaryLieDragt-Finn
MAD
PARMILA2D space charge
PARMELAPARMTEQ
IMPACT-ZIMPACT-TML/ISynergiaOPALORBITTRACKDynamionDESRFQBeamPathBeamBeam3DMAD-X/PTC…
CODES, CAPABILITIES & METHODOLOGIES FOR BEAM DYNAMICS SIMULATION IN ACCELERATORS
Freq maps
MXYZPTLKCOSY-INF
rms eqns
Normal FormsSymp Integ
DAGCPIC
3D space charge
WARP
SIMPSONS IMPACT
Partial list only; Many codes not shown
Integrated Maps
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov 4
Beam Dynamics Codes: Evolution(From R. Ryne’s Talk at HB-2008 Workshop)
1970 1980 1990Transport
2000
MaryLieDragt-Finn
MAD
PARMILA2D space charge
PARMELAPARMTEQ
IMPACT-ZIMPACT-TML/ISynergiaOPALORBITTRACKDynamionDESRFQBeamPathBeamBeam3DMAD-X/PTC…
CODES, CAPABILITIES & METHODOLOGIES FOR BEAM DYNAMICS SIMULATION IN ACCELERATORS
Freq maps
MXYZPTLKCOSY-INF
rms eqns
Normal FormsSymp Integ
DAGCPIC
3D space charge
WARP
SIMPSONS IMPACT
Partial list only; Many codes not shown
Integrated Maps
3D COLLECTIVE SELF-CONSISTENT
MULTI-PHYSICS
SINGLE PARTICLE OPTICS
1D, 2D COLLECTIVE
Par
alle
lizat
ion
beg
ins
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov 5
General Comments: Codes Availability, Sophistication, Limitations
Availability: Many useful beam dynamics codes exist for the simulation of proton and heavy ion linacs …- The variety is good but comes also with redundancy …- A lot of effort is put on benchmarking different codes …
Sophistication: A lot of them are pretty sophisticated- 3D External and Space Charge Fields.- Parallel Codes: Simulation of the actual number of particles in a beam bunch 1E9, 1E12 particles.- Detailed machine error simulations and correctionsLimitations: Still far from reproducing experimental data or to be used to support real-time machine operations.- Some effort is starting at SNS, J-PARC, GSI, …- At Argonne, TRACK is being developed in this direction ...
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov 6
Example of Code-Code and Code-Experiment Benchmarking: (From L. Groening (GSI), Talk at HB-2008 Workshop)
Schematic set-up of the experiments
Horizontal phase space plots at the DTL exit. Left: σo =35◦; centre: σo =60◦; right: σo =90◦. The scale is ± 24 mm (horizontal axis)
± 24 mrad (vertical axis)
Comparison: 3 Codes vs experiments
Initial Distribution: Measured in front of DTL Reconstructed and Input to Simulations
Horizontal Vertical
The 6D Distribution is parameterized to reproduce the measured 2D projections on phase space planes
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov 7
Our Experience: TRACK versus few other Codes
TRACK
Ions & electrons
Multi-beam
Support any element
1D,2D,3D fields
3D Poisson
Fast
Serial/Parallel
Errors + Corrections
IMPACT
Ions & electrons
Multi-beam
Most elem. No RFQ
1D, 2D,3D fields
3D Poisson
Fast
Serial/Parallel
Errors + corrections
ASTRA
Electrons & (H-)
Single beam
Less elem. No RFQ
1D, (3D) fields
3D Poisson
2-3x slower
Serial only
Errors only
PARMILA
Ions -
Single beam
Most elem. No RFQ
Hard-edge 2D fields
2D Poisson
Fast
Serial only
Errors only
TRACEWIN
Ions -
Single beam
Most elem. Calls toutatis
3D fields -
2-3D Poisson
Fast
Serial/-
Errors + corrections
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov 8
RIA Driver Linac Beam Dynamics: TRACK vs IMPACT
-0.2
0
0.2
Xc (
mm
)
-0.2
0
0.2
Yc (
mm
)
0
0.5
Δφc (
deg)
-0.1
0
0.1
X’ c (
mra
d)
0
0.1
Y’ c (
mra
d)
1
2
Δφrm
s (de
g)
0.5
1
Xrm
s (m
m)
0.5
1
Yrm
s (m
m)
2.5
5
7.5
Δφm
ax (
deg)
2
4
6
Xm
ax (
mm
)2
4
6
Ym
ax (
mm
)
50
100
ΔWrm
s (ke
V/u
)
0.09
0.095
0.1
ε xrm
s (m
m*m
rad)
0.09
0.095
0.1
ε yrm
s (m
m*m
rad)
20
40
60
ε zrm
s (de
g*ke
V/u
)
0
10
0 50 100Z-distance (m)
α x
0
2
0 50 100Z-distance (m)
α y
-2
0
2
0 50 100Z-distance (m)
α z
X-X’ plane Y-Y’ plane Δφ-ΔW plane
-3
-2
-1
0
1
2
3
-2 2X (mm)
X’
(mra
d)
-3
-2
-1
0
1
2
3
-2 2X (mm)
X’
(mra
d)
-3
-2
-1
0
1
2
3
-2 2Y (mm)
Y’
(mra
d)
-3
-2
-1
0
1
2
3
-2 2Y (mm)
Y’
(mra
d)
-150
-100
-50
0
50
100
150
-3 3Δφ (deg)
ΔW (
keV
/u)
-150
-100
-50
0
50
100
150
-3 3Δφ (deg)
ΔW (
keV
/u)
IMPACT TRACK IMPACT TRACK IMPACT TRACK
RIA driver linac,Medium-β section
Beam: U-2385Q: 72, 73, 74, 75, 76
In W ~ 12 MeV/uOut W ~ 90 MeV/uIn f = 115 MHzOut f = 345 MHz
IMPACT: BlackTRACK : Blue
Excellent agreement is obtained.References:
“RIA Beam Dynamics: Comparing TRACK to IMPACT”, B. Mustapha et al, PAC-05“The RIAPMTQ/IMPACT Beam Dynamics Simulation Package”, T. Wangler et al, PAC-07
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov 9
FNAL Proton Driver Beam Dynamics: TRACK vs ASTRA
Reference: “Benchmarking of Simulation Codes TRACK and ASTRA for the FNAL High-Intensity Proton Source”, J.-P. Carneiro, LINAC-06.
FNAL-PD Linac: RFQ to Linac end
Beam: 0 mA H-In: W ~ 2.5 MeV, Out: W ~ 8 GeV
ASTRA: Solid curvesTRACK: Dotted curves
Good agreement overall.
FNAL-PD Linac: RFQ to Linac end
Beam: 45 mA H-In: W ~ 2.5 MeV, Out: W ~ 8 GeV
ASTRA: Solid curvesTRACK: Dotted curves
Good agreement overall.
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov 10
SNS RFQ Beam Dynamics: TRACK vs PARMTEQ
References:“End-to-end Simulation of the SNS Linac using TRACK”, B. Mustapha et al, LINAC-08.
TR
AC
KP
AR
MT
EQ
99.63
0.211
0.213
Parmteq
105.86ε-z (deg-keV)
0.203ε-y (mm-mrad)
0.204ε-x (mm-mrad)
TRACKEmittance: N-RMS
SNS-RFQ: 32 mA H-, 1M particles simulated
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov 11
SNS Linac Beam Dynamics: TRACK vs PARMILA
“First TRACK Simulations of the SNS Linac”, B. Mustapha et al, LINAC-06.
TR
AC
K
PA
RM
ILA
-0.2
0
0.2
x 10-3
Xc (
cm)
-0.2
0
0.2
x 10-3
Yc (
cm)
0
50
Wc
(MeV
/u)
0
0.2
Xrm
s (cm
)
0
0.2
Yrm
s (cm
)
0
10
20
30
Δφrm
s (de
g)
0.5
1
Xm
ax (
cm)
0.5
1
Ym
ax (
cm)
0
50
ΔWrm
s (ke
V/u
)
0.075
0.1
0.125
4*ε x,
rms
0.075
0.1
0.125
4*ε y,
rms
3
4
5
4*ε z,
rms
0
1
2
ε x,10
0%
0
1
2
ε y,10
0%
0
20
40
ε z,10
0%
-10
0
10
α x
-10
0
10
α y
-5
0
5
α z
0
0.2
0.4
0 20 40Z-distance (m)
β x
0
0.2
0.4
0 20 40Z-distance (m)
β y
0
100
0 20 40Z-distance (m)
β z
X-X’ plane Y-Y’ plane Δφ-ΔW planeSNS linac:DTL section
Beam: 38 mA H-
In W ~ 2.5 MeVOut W ~ 87 MeVIn f = 402.5 MHzOut f = 402.5 MHz
PARMILA: BlackTRACK : Blue
Some differences:- Fringe field in PMQ- SC calculations
References:
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov 12
SPIRAL-2 Linac Beam Dynamics: TRACK vs TRACEWIN
End-to-end beam dynamics for a 0.5 mA A/q=6 ion beam along the SPIRAL-2 linac from the ion source to end of the linac.
The results were not superposed. But a good agreement between TRACK and TRACEWIN was observed.References:
“Preliminary Conceptual Design of a Heavy-Ion Injector for SPIRAL-2 Linac at GANIL”, Argonne Report to GANIL, unpublished.
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov 13
Summary and Recommendations to the Users
Summary:Many useful beam dynamics codes exist for the simulation of proton and heavy ion linacs …With different levels of sophistication …But they are still far from reproducing experimental data or to be used to operate an accelerator …
Recommendations to the Users:For consistency: Use 2-3 codes at leastStart with TRACE-3D or a similar envelope codePARMILA & PARMTEQ are good to use because it comes with very good documentationFinal design with error simulations should be done with more advanced codes such as TRACK, IMPACT, TraceWin
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov
The Beam Dynamics Code: TRACK
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov 15
The Beam Dynamics Code: TRACK
TRACK Main FeaturesA wide range of E-M elements with 3D fieldsEnd-to-end simulations from source to targetSimultaneous tracking of Multiple charge states ion beamsInteraction of heavy ion beams with strippersAutomatic transverse and longitudinal beam tuningError simulations for all elements: Static and dynamic errorsRealistic correction procedure: Transverse and LongitudinalSimulations with large number of particles for large number of seedsBeam loss analysis with exact location of particle loss
Recent UpdatesPossibility of fitting experimental data: beam profiles, …H- Stripping: Black body, Residual gas and Lorentz strippingThe design and simulation of electron linacs – Genetic optimizationParallel version is fully developed with good scaling up to 32K processorsPossibility of simulating the actual number of particles in a bunch
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov 16
TRACK: Extensive List of Supported Elements
Any type of RF resonator (3D fields)Static ion optics devices (3D fields)Radio-Frequency Quadrupoles (RFQ)Drift Tube Linacs (DTL)Coupled Cavity Linacs (CCL)Solenoids with fringe fields (model and 3D fields)Bending magnets with fringe fields (model and 3D fields)Electrostatic and magnetic multipolesMulti- Harmonic Bunchers (MHB)Axial Symmetric electrostatic lensesEntrance and exit of HV decksAccelerating tubes with DC voltageTransverse beam steering elementsStripping foils or films for heavy-ion beamsHorizontal and vertical jaw slitsTRACK was heavily used in the design and simulations of the RIA/FRIB and FNAL-PD linacs and recently in the simulation of the SNS linac.
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov 17
TRACK Application: Design and Simulations of the FRIB Linac
Injector: Two options w/wo MHBRFQ SC LINACMEBT
LEBTECR−IS
LEBT MHB RFQECR−IS SC LINAC
MEBT
100 % Transmission 80% TransmissionLarge long. emittance ~ 8 times smaller emittance
Qua
d
Qua
d
Qua
d
Qua
d
Qua
d
Qua
d
Qua
d
Qua
d
Qua
d
Qua
d
Qua
d
Qua
d
Ben
d
Ben
d
Ben
d
Ben
d
Ben
d
Ben
d
Ben
d
Ben
d
Mul
ti
Mul
ti
Mul
ti
Mul
ti
Bun
ch
Collim
0123456789
10
0 2 4 6 8 10 12 14Z-distance (m)
Xrm
s, Y
rms (
mm
)
Chicane: Collimation and Matching
-2.5-2
-1.5-1
-0.50
0.51
1.52
2.5
-2 0 2x (cm)
x’ (
mra
d)
-2.5-2
-1.5-1
-0.50
0.51
1.52
2.5
-2 0 2y (cm)
y’ (
mra
d)
-0.5-0.4-0.3-0.2-0.1
00.10.20.30.40.5
-10 0 10φ (deg)
ΔW/W
(%
)
-2.5-2
-1.5-1
-0.50
0.51
1.52
2.5
-2 0 2x (cm)
x’ (
mra
d)
-2.5-2
-1.5-1
-0.50
0.51
1.52
2.5
-2 0 2y (cm)
y’ (
mra
d)
-0.5-0.4-0.3-0.2-0.1
00.10.20.30.40.5
-10 0 10φ (deg)
ΔW/W
(%
)
Error simulations: Before and after Corrections
Different RF jitter errors: 0.5, 1 and 2 (deg, %)
-3
-2
-1
0
1
2
3
-2 0 2x (cm)
x’ (
mra
d)
-3
-2
-1
0
1
2
3
-2 0 2y (cm)
y’ (
mra
d)
-1.5-1
-0.5
00.5
1
1.5
-50 0 50φ (deg)
ΔW/W
(%
)
-3
-2
-1
0
1
2
3
-2 0 2x (cm)
x’ (
mra
d)
-3
-2
-1
0
1
2
3
-2 0 2y (cm)
y’ (
mra
d)
-1.5-1
-0.5
00.5
1
1.5
-50 0 50φ (deg)
ΔW/W
(%
)
-3
-2
-1
0
1
2
3
-2 0 2x (cm)
x’ (
mra
d)
-3
-2
-1
0
1
2
3
-2 0 2y (cm)
y’ (
mra
d)
-1.5-1
-0.5
00.5
1
1.5
-50 0 50φ (deg)
ΔW/W
(%
)
No corrections
Corrections
0.5 deg, 0.5 %
1.0 deg, 1.0 %
2.0 deg, 2.0 %
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov 18
TRACK Application: Design and Simulations of the FNAL-PD
Error simulations: 100 seeds, 1M particles each
0 deg0 %
1 deg1 %
2 deg2 %
Beam Emittances: before and after RF errors
Beam Envelopes
Beam Loss: Different RF errors
0.1
0.2
0.3
0.4
0.5
0 100 200 300 400 500 600 700Z distance (m)
4*ε x-
rms (
cm-m
rad)
0.1
0.2
0.3
0.4
0.5
0 100 200 300 400 500 600 700Z distance (m)
4*ε y-
rms (
cm-m
rad)
0
20
40
0 100 200 300 400 500 600 700Z distance (m)
4*ε z-
rms (
keV
/u-n
s)
0.1
0.2
0.3
0.4
0.5
0 100 200 300 400 500 600 700Z distance (m)
4*ε x-
rms (
cm-m
rad)
0.1
0.2
0.3
0.4
0.5
0 100 200 300 400 500 600 700Z distance (m)
4*ε y-
rms (
cm-m
rad)
0
20
40
0 100 200 300 400 500 600 700Z distance (m)
4*ε z-
rms (
keV
/u-n
s)
1 deg1 %
1
2
3
0 100 200 300 400 500 600 700Z distance (m)
Xm
ax (
cm)
1
2
3
0 100 200 300 400 500 600 700Z distance (m)
Ym
ax (
cm)
0
10
20
30
40
0 100 200 300 400 500 600 700Z distance (m)
φ max
(de
g)
1
2
3
0 100 200 300 400 500 600 700Z distance (m)
Xm
ax (
cm)
1
2
3
0 100 200 300 400 500 600 700Z distance (m)
Ym
ax (
cm)
0
10
20
30
40
0 100 200 300 400 500 600 700Z distance (m)
φ max
(de
g)
10-2
10-1
1
0 100 200 300 400 500 600 700Distance (m)
Los
t po
wer
(W
/m)
10-2
10-1
1
0 100 200 300 400 500 600 700Distance (m)
Los
t po
wer
(W
/m)
10-1
1
10
0 100 200 300 400 500 600 700Distance (m)
Los
t po
wer
(W
/m)
123 4 5 6 7
0 deg0 %
1 deg1 %
0 deg0 %
Fraction: 2E-5Peak: 0.1 W/m
Fraction: 1E-4Peak: 0.4 W/m
Fraction: 3E-2Peak: 35 W/m
Table:Errors and their typical values
See Paper in LINAC-06
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov 19
TRACK Application: End-to-end Simulation of the SNS Linac
RFQ Simulations Linac simulations from MEBT to HEBTEnvelopes: rms, max Emittances: 4*rms
Phase space plots
Transmission is consistent within ±1%
LINAC-08
Envelopes: rms, max Emittances: 4*rms
Phase space plots
Next steps- Error and beam loss simulations- Compare with experimental data
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov 20
TRACK Application: Design and Simulations of an electron linac
Layout of a linac for a future X-Ray FEL Oscillator
2 deg2 %
Energy spread
Bunch widthBeam Simulations
1 2 3 4 5 6 7 8 9 10 11 12 131 2 3 4 5 6 7 8 9 10 11 12 13
1- RF cavity with thermionic cathode, 100 MHz, 1 MV; 2- chicane and slits; 3- as an energy filter; 4- quadrupole triplet; 5- focusing solenoid; 6- monochromator of the beam energy, f=600 MHz; 7- buncher, f=300 MHz; 8- booster linac section, f=400 MHz; 9- RF cosine-chopper to form rep. rate 1 MHz to 100 MHz; 10- bunch compressor – I; 11- SC linac section, 460 MeV, f=1300 MHz; 12- bunch compressor – II; 13- initial section of the SC linac, f=1300 MHz.
See Paper in LINAC-08
0.001
0.01
0.1
1
10
0 20 40 60 80 100 120
Distance (m)
RM
S e
nerg
y sp
read
(M
eV)
Energy Filter
Velocity Buncher
Bunch compressor-I
Bunch compressor-II
Monochromator
0.1
1
10
100
1000
0 20 40 60 80 100 120
Distance (m)
Bun
ch R
MS
wid
th (
psec
)
Energy Filter
Velocity Buncher
Bunch compressor-I
Bunch compressor-II
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
0 2 4 6 8 10 12
Distance (m)
Em
ittan
ce (
m)
ExEy Emittance
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov 21
TRACK Application: Realistic Corrective Steering in HINS Linac
Design: the procedure was used to optimize the number, location of monitors and correctors as well as the correctors strengths.
Operations: could be implemented using real beam position monitors and beam steerers.
MonCorr Corr CorrCorr
Mon
MonCorr Corr
Mon
Corr CorrMon
CorrCorrCorrCorr
Virtual monitors and correctors are used
-1
-0.5
0
0.5
1
0 5 10 15 20 25 30 35Z distance (m)
Xct
r (cm
)
-10-505
10
0 5 10 15 20 25 30 35Z distance (m)
X’ ct
r (mra
d)
-1
-0.5
0
0.5
1
0 5 10 15 20 25 30 35Z distance (m)
Yct
r (cm
)
-10-505
10
0 5 10 15 20 25 30 35Z distance (m)
Y’ ct
r (mra
d)
0
20
40
60
80
100
120
140
160
-1250-1000-750 -500 -250 0 250 500 750 1000 1250B*L (G*cm)
Occ
urre
nce
Beam centers and angles before and after corrections
Correctors field strengths
-1
-0.5
0
0.5
1
0 5 10 15 20 25 30 35Z distance (m)
Xct
r (cm
)
-10-505
10
0 5 10 15 20 25 30 35Z distance (m)
X’ ct
r (m
rad)
-1
-0.5
0
0.5
1
0 5 10 15 20 25 30 35Z distance (m)
Yct
r (cm
)
-10-505
10
0 5 10 15 20 25 30 35Z distance (m)
Y’ ct
r (m
rad)
-1
-0.5
0
0.5
1
0 5 10 15 20 25 30 35Z distance (m)
Xct
r (cm
)
-10-505
10
0 5 10 15 20 25 30 35Z distance (m)
X’ ct
r (m
rad)
-1
-0.5
0
0.5
1
0 5 10 15 20 25 30 35Z distance (m)
Yct
r (cm
)
-10-505
10
0 5 10 15 20 25 30 35Z distance (m)
Y’ ct
r (m
rad)
-1
-0.5
0
0.5
1
0 5 10 15 20 25 30 35Z distance (m)
Xct
r (cm
)
-10-505
10
0 5 10 15 20 25 30 35Z distance (m)
X’ ct
r (m
rad)
-1
-0.5
0
0.5
1
0 5 10 15 20 25 30 35Z distance (m)
Yct
r (cm
)
-10-505
10
0 5 10 15 20 25 30 35Z distance (m)
Y’ ct
r (m
rad)
Sensitivity to monitors errors: 10, 30 and 100 μThe number and locations of monitors and correctors are varied until a reasonable correction scheme is obtained.
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov 22
TRACK Application: Operations of a Multi-Q Injector at ANL
20+21+20+&21+
20+21+20+&21+
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
0.18
0.2
-6 -4 -2 0 2 4 6X (cm)
a.u.
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
-3 -2 -1 0 1 2 3Y (cm)
a.u.
Measured beam profiles at the end of LEBT: left: horizontal, right: vertical.
Pepper-Pot images: Bi-209 beamsleft: 20+&21+right: 20+: blue, 21+:red.
0
200
400
600
800
1000
1200
1400
1600
1800
-4 -3 -2 -1 0 1 2 3X (cm)
a.u
0
200
400
600
800
1000
1200
-2 -1.5 -1 -0.5 0 0.5 1 1.5 2Y (cm)
a.u.
TRACK fit of measured profiles to extract the initial beam parameters at the source.
TRACK fit to find the quads setting to recombine the two charge state Bi-209 beams at the end of the LEBT.
Such a perfect recombination was not possible without a realistic simulation.
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov 23
TRACK Application: Automatic Transverse Tuning in RIA Linac
0.05
0.1
0.15
0.2
0.25
Xrm
s (cm
)
0.05
0.1
0.15
0.2
0.25
0 5 10 15 20 25 30 35 40 45 50Z-distance (m)
Yrm
s (cm
)
0.05
0.1
0.15
0.2
0.25
Xrm
s (cm
)
0.05
0.1
0.15
0.2
0.25
0 5 10 15 20 25 30 35 40 45 50Z-distance (m)
Yrm
s (cm
)
Automatic Transverse TuneOriginal Manual Tune
X- and Y-rms beam sizes before and after applying the automatic transverse tuning procedure. The beam is a two-charge state uranium beam in the first section of the RIA/FRIB driver linac.
A similar procedure was developed to produce smooth longitudinal envelopes by fitting the RF cavities field amplitudes and phases.
Purpose: Tune the linac for a given beam and produce smooth transverse beam dynamics.
Method: Minimize the fluctuations in the RMS beam sizes along the considered section.
Fit Function:
where and are the RMS beam sizes at the entrance of the section or after the first focusing period, the sum index i runs over the focusing periods in a given section and and are the allowed errors on the RMS beam sizes.
Fit Parameters: Field strengths in focusing elements
This method is general and should produce good results for both periodic or non periodic accelerating structures.
∑∑ 22
−++−+=i
Y
rmsi
rmsrmsi
X
rmsirms
rms
rmsrms
YYY
XXXF
εε
200
200 )()(
0rmsX 0
rmsY
XrmsεYrmsε
Developed and used for design optimization this procedure could very well be applied to a real machine using beam profile measurements to reduce beam mismatch.
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov 24
TRACK Application: Longitudinal Fine Tuning before a Stripper
-8
-6
-4
-2
0
2
4
6
8
0 20 40 60 80 100 120Distance (m)
Δφ (
deg)
-100
-75
-50
-25
0
25
50
75
100
0 20 40 60 80 100 120Distance (m)
ΔW (
keV
/u)
-8
-6
-4
-2
0
2
4
6
8
0 20 40 60 80 100 120Distance (m)
Δφ (
deg)
-100
-75
-50
-25
0
25
50
75
100
0 20 40 60 80 100 120Distance (m)
ΔW (
keV
/u)
-300
-200
-100
0
100
200
300
-10 -8 -6 -4 -2 0 2 4 6 8 10Δφ (deg)
ΔW (
keV
/u)
-300
-200
-100
0
100
200
300
-10 -8 -6 -4 -2 0 2 4 6 8 10Δφ (deg)
ΔW (
keV
/u)
Black: Ref. 74+ of U-238Colors: 72+,73+,75+ and 76+
10-2
10-1
1
10
10 2
0 100 200 300 400 500Distance (m)
Los
t po
wer
(W
/m)
10-2
10-1
1
10
10 2
0 100 200 300 400 500Distance (m)
Los
t po
wer
(W
/m)
Purpose: Tune a linac section to minimize the logitudinal emittance of a multiple charge state beam right before stripping.
Method: Match the longitudinal beam centers and Twiss parameters of the different charge state beams:
Fit Function:
where is the desired beam energy and is the corresponding error.
are the allowed errors on the relative energy, phase and shifts of the individual charge state beams from the central beam.
Fit Parameters: RF cavities field amplitudes and phases.
min;0;0;0;00 →→→Δ→Δ→ qiqiqiqiq WWW βαφ
∑∑∑∑ ++Δ+Δ+−= 22Δ
2Δ
qiqi
qi
qi
qi
qi
qiw
qiq WWWF
w
βε
αεφ
εε αφ
222200
2
)(
Measuring the energy and phase of individual charge states, we should be able to match their beam centers, … Reduced beam loss in the high-energy section
0W Wε
αφ εεε ,, ΔΔW
α
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov 25
P-TRACK Application: One to One RFQ Simulation ~ 1 B particles
Simulated the actual number of particles in 45 mA proton beam at 325 MHz accelerated in a RFQ from 50 keV to 2.5 MeV 865 M particles on 32768 procs.Benefits of simulating a large number of particles: actual number if possible- Suppress noise from the PIC method: enough particles/cell- More detailed simulation: better characterization of the beam halo
Phase space plotsfor 865 M protonsafter 30 cells in theRFQ.
(x, x’) (y, y’) (Δt, ΔW’)
3D beam: 100M
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov 26
P-TRACK Application: Large Scale Error Simulations 10M/Seed
Simulated machine errors with 10M particles per seed FNAL-PD linac:- ~ 2000 elements, 1.7 Km long- misalignment errors and (1%,1 deg) RF errors- includes H- stripping: Black body, residual gas and Lorentz stripping. Benefits of simulating a large number of particles/seed:- Study beam loss to the lowest possible level.
Envelopes RMS emittances Beam loss
Lost fraction: 9 E-4Peak loss: 0.9 W/m
With H- stripping, the fraction lost increased by almost one order of magnitude Linac &Transfer line should be cooled
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov 27
Future Developments: Parallel Optimization Tools
So far, the developed optimization tools were used only with the serial version of TRACK Very time consuming.
Large scale parallel computing is necessary for timely optimizations …
The fully parallel version of TRACK is now ready
Next: Test the existing tools with the Parallel version of TRACK
First: Try parallel tracking and serial optimization.
Second: Investigate the use of parallel optimization algorithms developed at the Mathematics and Computer Science division of Argonne (TAO: Toolkit for Advanced Optimization, PETSc).
ESS-Bilbao Workshop Beam Dynamics Codes … P. Ostroumov 28
More Developments Towards a Model Driven Accelerator
More tools are needed to fit the experimental data using a beam dynamics code.
Develop interfaces between the beam diagnostic devices and the beam dynamics code Calibrate and analyze the data to input to the code.
Numerical experiments could be used to test the tools before implementation to the real machine Produce detector like data from the code.
Larger scale realization: ATLAS at ANL, may be SNS Linac …
Large scale parallel computing will be needed to support real time operations of the machine.