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TRANSCRIPT
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Design Status of the PEFP RCS
HB2010, Morschach, Switzerland
J.H. Jang1) Y.S. Cho1), H.S. Kim1), H.J. Kwon1), Y.Y. Lee2)
1)PEFP/KAERI, 2)BNL
(www.komac.re.kr)
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PEFP (proton engineering frontier project) Status
Expansion Plan of PEFP
Design Concept of the PEFP RCS (rapid cycling synchrotron)
Lattice Design and Beam Dynamics
Summary
Contents
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Project : Proton Engineering Frontier Project (PEFP)
21C Frontier Project, Ministry of Education, Science & Technology
Project Objectives :
1st : Developing & constructing a proton linear accelerator (100MeV, 20mA)
2nd : Developing technologies for the proton beam utilizations &
accelerator applications
3rd : Promoting industrial applications with the developed technologies
Project Period : 2002.7 – 2012.3 (10 years)
Project Cost : 128.6 B Won (Gov. 115.7 B, Private 12.9 B) (Gyoungju City provides the land, buildings & supporting facilities)
Overview of PEFP
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Output Energy (MeV) 20 100
Peak Beam Current (mA) 20 20
Max. Beam Duty (%) 24 8
Avg. Beam Current (mA) 4.8 1.6
Pulse Length (ms) 2 1.33
Max. Repetition Rate (Hz) 120 60
Max. Avg. Beam Power (kW) 96 160
Schematics of PEFP Linac & Beamlines
Features of the PEFP linac
• 50 keV Injector (Ion Source + LEBT)
• 3 MeV RFQ (4-vane type)
• 20 & 100 MeV DTL
• RF Frequency : 350 MHz
• Beam Extractions at 20 or 100 MeV
• 5 Beamlines for 20 MeV & 100 MeV
- Beam to be distributed to 3 BL via AC
Future
Extension
100 MeV Beamlines 20 MeV Beamlines
TR105 TR101 TR25 TR21
TR23 TR22 TR24 TR102 TR103 TR104
100 MeV 20 MeV 3 MeV
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Status of Accelerator Development
100 MeV Beam 20 MeV Beam
Step 3
(’08.04 ~ ’12.03)
Step 2
(’05.07 ~ ’08.03)
Step 1
(’02.07 ~ ’05.06)
RF RF RF RF RF
91~102 80~91 69~80 57~69 45~57
DTL103 DTL104 DTL105 DTL106 DTL107 MEBT
RF RF
33~45 20~33
DTL101 DTL102
RF
RFQ IS
RF
DTL21~DTL24
Control & Diagnostics
Operating 2010
Fully developed & integrated up to 20 MeV at KAERI site in Daejeon
The fabrication of tanks up to 91MeV has been finished.
Last tank will be fabricated in this fiscal year.
Completed
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The Project Site
The land (440,000 m2) provided by Gyeongju municipal government.
(The capital of Shilla dynasty for 992 years, from BC 57 to AD 935.)
Seoul
KAERI (Daejeon) Gyeongju
Daegu
Pusan
Express Railway (KTX)
(New Gyeongju Station)
Free Way
(Gyeonju IC)
Phase
II
Phase
I
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The Site Plan
Proton Accelerator Research
Center
② ③
④
⑨
⑩
⑪
⑤
⑥ ⑦
①
⑫
⑧
⑦ Water Storages
⑧ Main Office Building
⑨ Regional Cooperation Center
⑩ Dormitory
⑪ Information Center
⑫ Sewage Plant
① Accelerator Tunnel
② Experimental Hall
③ Ion Beam Facility
④ Utility Building
⑤ Substation
⑥ Cooling Tower
1,100 m 450 m
40
0 m
Reserved for
the Future Expansion
Phase I
(2002~2012)
Phase II
(2012 ~) Express Railway (Under construction)
Phase - II
Phase - I
Gyeong-bu
Freeway
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PEFP 20 MeV Linac
Waveguide WR2300
Klystron for DTL 350 MHz 1 MW CW
LEBT 3 MeV RFQ
350 MHz 4-Vane
Injector
50 keV 40 mA 20 MeV DTL
4 -Tank 150-DT
Klystron for RFQ 350 MHz 1 MW CW
Beam Profile Target station
for user
Extracted first beam (July 2005)
Obtained operation license (June 2007)
- Avg. current: 0.1 A,
- Rep. Rate: 0.1 Hz, 4 hrs/week
Started beam service (June 2007)
Achieved design performance (May 2008)
4cm
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Target Station for 20-MeV beams (at KAERI site)
-30 -20 -10 0 10 20 30
0
1000
2000
3000
4000Data: Data1_B
Model: Gauss
Equation: y=y0 + (A/(w*sqrt(PI/2)))*exp(-2*((x-xc)/w)^2)
Weighting:
y No weighting
Chi^2/DoF = 26392.98749
R^2 = 0.98215
y0 354.12642 ± 24.15184
xc 0.00098 ± 0.07989
w 10.29726 ± 0.18919
A 44757.8051 ± 893.56993
N.O
of p
art
icle
s
X axis [cm]
1m
Gauss fit of Data1_B
External beam
DTL
QM (triplet)
Target
Lead shielding
Concrete
Shielding
Beam energy / current : 20-MeV, 1uA (average) – 20mA peak, 50us, 1Hz
Target room dimension : 0.6m(width)x2.6m(length)x1.8m(height)
External beam diameter : 10cm (1m transport after beam window)
Beam window : 0.5mm thick Al
Shielding : gamma-10cm thick lead, neutron – 15cm thick concrete
License issued at June, 2007 (May, 2008 for 1uA license)
Irradiated Samples
103
178155
0
50
100
150
200
2007 2008 2009
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100-MeV DTL tanks
tank cell # length
(m)
energy
(MeV)
DTL101 34 6.738 33.1
DTL102 28 6.707 45.3
DTL103 25 6.792 57.3
DTL104 23 6.877 69.1
DTL105 21 6.778 80.4
DTL106 20 6.870 91.7
DTL107 19 6.880 102.6
The fabrication of tanks up to 91MeV (DTL101~DTL106)has been finished.
Last tank will be fabricated in this fiscal year.
DTL tanks at Gyeonju office
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Beam Lines
BL25
BL21 BL22
BL23
BL24
BL105
BL101 BL102
BL103
BL104
Beam
Line
Application
Field
Rep.
Rate
Avg.
Current
Irradiation
Condition
TR21 Semiconductor 60 Hz 0.6 mA Hor. Ext.
TR22 Bio-Medical
Application 15 Hz 60 A Hor. Ext.
TR23 Materials, Energy &
Environment 30 Hz 0.6 mA Hor. Ext.
TR24 Basic Science 15 Hz 60 A Hor. Ext.
TR25 Radio Isotopes 60 Hz 1.2 mA Hor. Vac.
Beam
Line
Application
Field Rep. Rate
Avg.
Current
Irradiation
Condition
TR101 Radio Isotopes 60 Hz 0.6 mA Hor. Ext.
TR102 Medical Research
(Proton therapy) 7.5 Hz 10 A Hor. Ext.
TR103 Materials, Energy &
Environment 15 Hz 0.3 mA Hor. Ext.
TR104 Basic Science
Aero-Space 7.5 Hz 10 A Hor. Ext.
TR105 Neutron Source
Irradiation Test 60 Hz 1.6 mA Hor. Vac.
QM AC Dipole 25 BM 45 BM
Designed by reflecting user’s requirements
Developed components, BM, QM, ACM, & Beam Instruments
AC magnet distributes proton beams to three target rooms
Fabricated at IHEP (China)
Beam Line magnets
at Gyeonju office
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Options of PEFP Expansion
▪ 1 GeV Linac + Acc. Ring
⇒ 2 MW Spallation Neutron Source
⇒ 250, 400, 1000 MeV Proton Beam
▪ 200 MeV Linac + 2 GeV RCS
⇒ 0.5 MW Spallation Neutron Source
⇒ 250 MeV Proton Beam
▪ 400 MeV Linac + 8 GeV PS
⇒ 8 GeV Proton Beam
Two Options Proposed by Science & TEchnology Policy Institute (Feb, 2009)
: in a research report on “Long-term Planning for Proton Engineering Frontier Project”
Option 2
Option 1
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Design concept of PEFP RCS
Purpose
• Spallation neutron source: energy > 1GeV
• Medical application, Radioisotope, Nuclear physics, etc: energy ~ 450 MeV
Design concept
• PEFP 100MeV linac: injector of the RCS
• Final energy of RCS: 1 GeV (initial stage)
• Beam power of 60 kW (initial stage)
• Beam power of 500kW through 3 upgrade stages: injection and extraction energies,
repetition rate
• Injection: charge exchange and painting
• Extraction: fast and slow extraction
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Upgrade Plan
- Injection energy: from 100 MeV to 200 MeV
- Extraction energy: from 1 GeV to 2 GeV
- Repetition rate: from 15 Hz to 30 Hz
Injection
Energy
(MeV)
Extraction
Energy
(MeV)
Repetition
Rates
(Hz)
RF
Voltage
(kV)
Output
Power
(kW)
Initial 100 1000 15 75 60
1 100 1000 30 140 120
2 100 2000 30 260 250
3 200 2000 30 250 500
- In the following contents, we will focus on the RCS design study in initial stage
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Design parameters of PEFP RCS (initial stage)
Beam power (kW) : 60
Injection energy (MeV) : 100
Extraction energy (MeV) : 1000
Injection type : Charge exchange
Extraction type : Fast & Slow
Repetition rate (Hz) : 15
Circumference (m) : 224.16
Lattice structure and cell number : FODO and 20
Number of dipole : 32
Dipole field at 1 GeV (T) : 0.56
Super-period : 4
Tunes of QX /QY : 4.39/4.29
T : 4.4
RF harmonic number : 2
Required RF voltage : 75 kV
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Lattice Design (1/2)
• Four-fold symmetry :
To reduce lower-order resonance
• FODO lattice : pseudo 20 fold symmetry
• Dispersion free long straight sections :
– Injection and Extraction
– RF system
– Collimator
• Arc straight sections with missing dipole :
– Momentum collimation
– Slow extraction
Fast Extraction
Injection
Slow Extraction
RF
Ac
ce
lera
tion
RF
Ac
ce
lera
tio
n
Lattice Structure of PEFP RCS
Momentum Collimation
Collimator
65.08 m
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Lattice Design (2/2)
• Lattice: FODO
• Beam optics: MAD8
- dispersion suppression in the straight sections
• Maximum beta functions: 18.3 m / 18.7 m
• Dispersion function < 6.0 m
• beta functions and dispersion function
in one super-period
• Physical acceptance: 560 mm-mrad
• Collimator acceptance: 350 mm-mrad
• Transverse emittance: 280 mm-mrad
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Closed Orbit Distortion and Correction
Parameters Values
Magnetic Field Error of BM (dB/B) =10^-4
Magnetic Field Error of QM (dB/B) =10^-4
Displacement Error dx = dy = ds= 0.3mm
Rotation Error dx, dy, dz = 1.0 mrad
• MAD8: MICADO method
• Number of used BPM : 40
• Number of used corrector magnets : 40
• Maximum orbit distortion before/after corrections :
±10mm / ± 1mm
• Statistical analysis to determine the specification of the
corrector magnets.
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Chromaticity Correction
• Natural chromaticity: -4.32 / -4.64
• Assuming momentum spread : ±1%
• Maximum tune spread due to chromaticity:
dQx = 0.043, dQy = 0.046
(This is very small compared with the
space charge tune shift of 0.2)
Horizontal
Vertical
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Dynamic Aperture Study
• DYNAP routine in MAD8
• Tracking Method: LIE Algebra Method
• p/p < 0.7 % ( Injection Simulation Result )
• Closed Orbit Distortion Effects
• Multipole Effects of Dipole Magnet
• Most dominant effects: COD
(After correction, DA is larger than the stable
region)
p/p
effects
COD
effects
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• Painting scheme: Correlated • Macro – particles number: 4.0*104
• Circumference [m] : 224.16 • Linac peak current [mA] : 20
• Injection energy [MeV] : 100 • Injection time [ms] : 0.349
• Machine tunes(Qx/Qy) : 4.39/4.28 • Foil Thickness : 200 μg/cm2
• Linac emittance [pi mm mrad] : 1.0 • Number of Turns Injected : 200
• Beam emittance [pi mm mrad] : 280 • Space Charge effect : YES
Injection
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Transverse Correlated Painting
• correlated painting: ORBIT code
• Spatial beam size of horizontal and vertical coordinate: 55mm
bump function
x-y
x-x’
y-y’
distribution
injectiont
ttf 1)(
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Acceleration Simulation (1/3)
Time structure of the RCS input beam: injection energy: 100 MeV
repetition rate: 15 Hz
Linac beam just before injection : One macro-pulse includes 400 mid-pulses ( h=2 )
[ Macro-Pulse ] [ Mid-Pulse ]
RCS beam just after injection : One pulse includes two bunches
bunch length of 500 ns ~ Chopping factor of 57%
[ Pulse ] [ Bunch ]
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Acceleration Simulation (2/3)
- This simulation is for the initial stage: ORBIT
- Magnetic field ramping: sinusoidal
- Peak accelerating voltage < 75 kV
- Synchronous phase < 35.3
particle distribution in longitudinal phase space
magnetic field ramping
peak voltage
sync. phase
18.7 kV
75.0 kV
- Energy (E): Gaussian with = 0.2 MeV
- Phase (): uniform in 103 degrees
( chopping factor = 57%)
Energy
Phase
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Acceleration Simulation (3/3)
- final energy = 1003 MeV
- final capture rate = 99.9 %
200 turns
(100.1 MeV, 100 %)
6000 turns
(210.5 MeV, 99.93 %)
2000 turns
(113.8 MeV, 99.96 %)
10000 turns
(362.5 MeV, 99.91 %) 31200 turns
(1003 MeV, 99.91 %)
18000 turns
(700 MeV, 99.91 %)
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Summary
RCS is an option for PEFP expansion.
1 GeV RCS with the 100MeV linac as an injector
- upgradable up to 2 GeV (STEPI result for PEFP future study)
- fast extraction for spallation neutron source
- slow extraction for medical application, RI facility, nuclear physics
- lattice design, beam dynamics calculation including acceleration : MAD, ORBIT
Further work
- 2GeV study with 200 MeV injection.
- beam transport line (linac to RCS, RCS to target) and extraction
- components design
- instability issues, slow extraction, etc.
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Thank you for your attention !!