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Chuan Zhang
Institute for Applied Physics, Goethe-University
52nd ICFA Advanced Beam Dynamics Workshop on High-Intensity and High-Brightness Hadron Beams
HB2012, Beijing, China, Sept. 17-21, 2012
RFQ Beam Dynamics Design for Large Science
Facilities and Accelerator Driven Systems
RFQ
RFQ
Background
Real Examples
Conclusion Design
Procedures
3 HB2012, Beijing, China, Sept. 19, 2012 Chuan Zhang
Accelerators for Science & Applications
Plot: U. Amaldi & K. Bethge
© ENEA, 2001
700 years 106 years
© ENEA, 2001
700 yeears 106 yeeeeears
4 HB2012, Beijing, China, Sept. 19, 2012 Chuan Zhang
Accelerator-Based Science Centers
RHIC 2000
SNS 2006
LHC 2008
FAIR 2017
5 HB2012, Beijing, China, Sept. 19, 2012 Chuan Zhang
Accelerator-Driven Systems
MYRRHA 2023
China ADS 2032
6 HB2012, Beijing, China, Sept. 19, 2012 Chuan Zhang
“Everything is Hard at the Beginning”
Cycle Duty Intensity Peak
Space- Charge
Sparking / Cooling
Low Beam Losses (Hands-on Maintenance)
Good Beam Quality (Downstream HoM, Quenching)
Short Length (Costs)
Modest V
+ +
+ +
Pic: J-PARC
7 HB2012, Beijing, China, Sept. 19, 2012 Chuan Zhang
LANL Four-Section Procedure
K-T Condition: to maintain a constant beam density for an adiabatic bunching • Longitudinal small oscillation frequency • Separatrix length in cm
20
2
2
rMcqUB
8 HB2012, Beijing, China, Sept. 19, 2012 Chuan Zhang
The Shortcomings of the LANL Method
T.P. Wangler, Principles of RF Linear Accelerators (1998), pp.241
GB: beam bunching is not efficient (will lead to a long structure).
SH: could be an important source of unstable particles.
Constant B: deal with the longitudinal and tranverse planes separately;
and MOST IMPORTANT, it ignores the space-charge effects.
9 HB2012, Beijing, China, Sept. 19, 2012 Chuan Zhang
New Four Section Procedure
NFSP FSP
Balanced
Transverse focusing strength B
Transverse
C. Zhang et al., NIM-A 2008 & PRST-AB 2004
Accelerated
Softened
d
NFSP FSP
Longitudinal
-270 -180 -90 0 90-0.2
-0.1
0.0
0.1
0.2
(Wi -
Ws) /
Ws
[deg]
s
separatrix
10 HB2012, Beijing, China, Sept. 19, 2012 Chuan Zhang
FAIR: Facility for Antiproton and Ion Research
95 keV 3.0 MeV 70 MeV
FAIR p-linac
GSI Today
FAIR
11 HB2012, Beijing, China, Sept. 19, 2012 Chuan Zhang
FAIR Proton RFQ vs. SNS RFQ
Parameters SNS FAIR
Ion H- H+
Duty cycle [%] 6.2 0.0144
Ipeak [mA] ~60 (35) 45 70 100
f [MHz] 402.5 325.44
Win [MeV] 0.065 0.095
Wout [MeV] 2.5 3
U [kV] 83 80
intrans.,norm., rms [ mm mrad] 0.2 0.3
outtrans.,norm., rms [ mm mrad] 0.21
0.21 0.30 0.30
0.30 0.30
0.31 0.31
outlongi., rms [ MeV deg] 0.103 0.163 0.153 0.152
L [m] 3.7 3.2
Transmission [%] ~90 98.7 97.2 95.3
C. Zhang, A. Schempp, NIM-A 2009
SNS
Data: J. Staples
FAIR
For accelerated particles only
12 HB2012, Beijing, China, Sept. 19, 2012 Chuan Zhang
Design Results of the FAIR Proton RFQ
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
0.1
0 20 40 60 80 100 120 140 160 180 200 220Cell Number
εno
rm.,
rms
[π c
m m
rad
]
x, 100%
y, 100%
z, 100%
z, 99%
max.: (177, 0.4)
95
95.5
96
96.5
97
97.5
98
98.5
99
99.5
100
0 25 50 75 100 125 150 175 200 225 250 275 300 325 350
Z [cm]
Tota
l Bea
m T
rans
mis
sion
T [%
]
45mA, designed 70mA, unmatched 70mA, matched100mA, unmatched100mA, matched
C. Zhang, A. Schempp, NIM2009
19799 / 125202
LEBT Output Dist. Provided by L. Groening
13 HB2012, Beijing, China, Sept. 19, 2012 Chuan Zhang
( 2011 – 2014 )
( 2005 – 2010 )
European ADS Projects
Specifications XT-ADS EFIT MAX
Design current 5 mA 30 mA 5 mA
Beam trips >1s: < 5 per three-month
>1s: < 3 per year
>3s: < 10 per three-month
Time structure CW, with 200μs zero-current holes N. Pichoff, EPAC 2001
14 HB2012, Beijing, China, Sept. 19, 2012 Chuan Zhang
Design of the EUROTRANS RFQ
30mA
30mA
5mA
Eth=2.16MeV for 65Cu(p, n)65Zn
Total losses: 0.106%
15 HB2012, Beijing, China, Sept. 19, 2012 Chuan Zhang
EUROTRANS: a Toy! MAX: a Real Boy !
Rp ~ f -1.5
H. Vernon Smith, LINAC 2000
9-Hour CW Operation @ LEDA
Plot: MAX Deliverable 2.1
Ek: 1.8
16 HB2012, Beijing, China, Sept. 19, 2012 Chuan Zhang
EUROTRANS RFQ vs. MAX RFQ
C. Zhang, H. Klein, H. Podlech et al., IPAC 2011, WEPS043
17 HB2012, Beijing, China, Sept. 19, 2012 Chuan Zhang
Project X Injector Experiment & China ADS Injector II
PXIE at FNAL China ADS Project
Parameters PXIE China ADS
Ion type H- H+
Input energy [keV] 30 35
Output energy [MeV] 2.1 2.1
Duty factor [%] 100 100
Frequency [MHz] 162.5 162.5
Beam current [mA] 5 (nominal); 1-10 15 (nominal); 1-20
Input transverse emittance [ mm-mrad] 0.25 (norm. rms) 0.3 (norm. rms)
Transverse emittance growth [%] ≤10 ≤10
Output longitudinal emittance [keV-nsec] ≤0.8 ≤1.0
Transmission [%] 95 95
TWISS Parameter [%] ≤1.5 ≤1.5
18 HB2012, Beijing, China, Sept. 19, 2012 Chuan Zhang
Evolutions of Main RFQ Parameters
19 HB2012, Beijing, China, Sept. 19, 2012 Chuan Zhang
Beam Transport Simulations
20 HB2012, Beijing, China, Sept. 19, 2012 Chuan Zhang
Conclusions
• The RFQ accelerator is the standard injector.
• Challenges to modern RFQs: • High beam intensity
• High duty factor even CW
• An efficient design method for modern RFQs, “New Four
Section Procedure”, has been developed:
• Applied for the designs of more than 20 RFQs: • Ion species: proton – uranium (A/q: 1 – 59.5)
• Frequency [MHz]: 36.136 – 352
• Peak beam intensity [mA]: 0 – 200 (300)
• Duty factor [%]: 0.0144 – 100
• Proven experimentally: • New EBIS RFQ for BNL
• New HLI RFQ for GSI
M. Okamura et. al., PAC 2009
21 HB2012, Beijing, China, Sept. 19, 2012 Chuan Zhang
Vielen Dank
Thank You