1. ISOL cyclotron for the RISP
Jong-Won Kim
RI beam production systems team
Institute for Basic Science/RISP
June 26, 2015

2. Layout of the ISOL and In-flight systems for RI beam production
IFS
Injector
ISOL
High
Energy
Exp. 1
Cryogenic
System
Low
Exp.
SCL1
SCL2
Cyclotron
Exp. 2
SCL3
EBIS-CB
High radiation area
Cyclotron

3. Configuration of in-flight separator
beam dump
degrader F1 F2 F3 F4
Dipole
Quadrupole
Sextupole
Primary
beam
238U beam energy: MeV/u
Max. beam power: 400 kW
HTS quadrupole
Cryostat of quad triplet F5
Pre-separator F6
Main separator
Main specifications
Dispersive focal plane:
F1,F3, F5, F7 F7
Max. B
~10 Tm
p/p
<±3%
Angular accep.
±40 mrad
±50 mrad
Achromatic focal plane:
F2 , F4, F8 F8

4. Design of in-flight separator facilityB1 B2 B3
IFS floors
Top view F1 F5 F2 F4 F6 F3 F7
Power supply
Room (B1)
Counting Room
(B1) F8
20 m
38 m
19.56 m
22.15 m
81 m
141 m
Side view
26.5 m 1F
15 m B1
Power supply
Room
Counting Room
4 m
9 m B2
4 m B3
Radiation dose map
1F: Air conditioning
B1: Hot cell remote handling, Counting room
B2:: Beam area, Vacuum pumps, etc.
B3: Radiation waste, Drain tanks, Waste water storage
[μSv/hr]
16O beam, 590 MeV/u, 400 kW
Power supply and Counting rooms

5. Design of the ISOL facility
TIS
EBIS
Ion
132Sn1+
132Sn33+ E
60 keV
5 keV/u
ISOL Driver: MeV, H- 1 mA cyclotron
RF cooler+EBIS+A/q
Pre-separator
Target/Ion Source
Cyclotron
Pre-Separator
m/m = 300
EBIS
RFQ Cooler
3 mm mrad, 1 eV
Post linac
MR-TOF
The layout still evolving
UCx target: 10 kW (Dia. 5 cm, 1.3 mm 19 disks)
Test stand for target ion source, front-end mass separator on HV platform

6. Design of the ISOL targets
Fission rate
132Sn production rate
132Sn (at exp. room)
RISP
10 kW
1.58×1013 /s
2.18×109 /s
1.1×107 pps
35 kW
1.15×1014 /s
1.59×1010 /s
7.9×107 pps
SPES 8 kW
7.6×1012 /s
~ 109 /s
Target material for 10 kW: UCx
Beam: 5 cm uniform

7. Specification of commercial 70 MeV Cyclotrons
Categories
BEST
IBA
Sumitomo*
Accel Particle
Proton　
Emax,
Imax
35~70MeV
1mA*
30~70MeV
750uA
(Fixed) 70MeV
1mA
Magnet Sectors 4
B (Hill, Vaelly)
1.6T, 0.12T
1.7T, 0.12T
1.7T, 0.5T
Harmonics 2
Freq. (MHz)
56.2 30 73
Ion Source
multi cusp
Arc MultiCUSP
Volume CUSP
Operating
Site
INFN, Legnaro (2015)
ARRONAX,
France(2010)
N/A
Proposals in 2013

8. Further specification of the cyclotrons
Categories
BEST
IBA
Sumitomo*
RF System
No. of Dees 2
Dee Angle
35o
30o
45o
Harmonics 4
Frequency (MHz)
56.2 30 73
Dee Voltage (kV)
60 to 70 50
Injection System
Ion Source Type
multi cusp
Arc MultiCUSP/ECR
Volumic CUSP
H- Current
15 ~ 20 mA
5mA
10mA
Inflector
spiral
Extraction System
No. exit port/beam lines
2. / 4.
2. / 6.
Carbon foil (life time/uAh)
1mA Carousel with 6 foils
20,000
0.5mA 1.0mA
Beam emittance(x,y/mm.mrad)
6.2, 3.8
horizontal 4 pi
~15 pi / 5 pi
Vacuum System
< 1.5x10-7 Torr
1x10-7 mbar
< Pa
Control System
PLC　

9. Two previous meetings on 70 MeV H- cyclotron
1. Workshop on compact H- cyclotron for rare isotope production (Nov. 7-8, 2013)  Freddy Poirier (ARRONAX, France)  T. Zhang (CIAE, China)  R. Johnson (Best Cyclotron)  Y. Koyabu (Sumitomo)  Benoit Nactergal (IBA) 2. Cyclotron review meeting on 70 MeV H- cyclotron subsystem specification (April 3-4, 2014) T. Zhang (CIAE, China) L. Calabretta (INFN, Italy) A. Goto (Yamagata, Japan)

10. Issues discussed in Workshops
Scope of commercial order
- Cyclotron (up to two switching magnets of the extraction ports)
- Cyclotron + two beam delivery lines up to wobbler
- Some major spare parts
- Pulsed beam option
Continuous operation with one carrousel (>10 days)
- How many carbon foils in one carrousel?
Stability of the beam current
- How to monitor the beam current and beam shape? how accurately?
- Any feedback to stabilize the beam current? Time constant?
- Sudden beam current jump should be avoided. Can this be avoided?
Other issues
- Minimum time for beam stop in case of emergency
- Any plan to measure carbon foil lifetime in beam current of mA

11. Uniform beam formation by wobbling method
TRANSPORT calculation for two configurations
(point to parallel focusing)
Initial beam distribution
wobbling pattern
Dependence on the radius of gyration
Uniformity and beam loss vs. radius of gyration
r (cm)
Uniformity
Beam loss (%)
1.8
±9.2 29
1.9
±4.8 34
2.0
±6.0 36
Two parameters
 beam width
 radius of gyration

12. Dependence on radius of gyration with use of octupole magnets
Use of multipole magnet to reduce beam losses
Use both multipole magnet and wobbling method
 Flexible against beam shape variation
Octupole off
Octupole on
Dependence on radius of gyration
with use of octupole magnets
Beam loss
reduction
34%21%
X (cm)
Calculated by using GICOSY

13. An injection beam line for pulsed beam (option)
Pulsed beam for TOF measurement
Proton beam time structure
Neutron beam
Time
MHz
Vmax=3 kV
SIMION simulation
Pattern of pulsed HV

14. Carbon foil extraction system
Best Cyclo.
IBA
Number of exit ports 2
Carbon foil loading system
Multiple, Automatic
Carbon foil thickness
120 μg/cm2
Stripping efficiency
99.96 %
Lifetime of foil at 1 mA ?  ?
Extracted beam emittance at different energies
T [MeV] 70 60 35
εH[π∙mm∙mrad]
3.0
3.3
6.0

15. Heat generation on the foil by stripped electrons
 Power deposit on carbon foil
P = ∆W x I
∆W: beam energy loss
I: current
 70 MeV 1mA with 6 mm, 1um thick target
- Energy by protons : 1.7keV x 1x10-3A = 1.7 W
- Energy by two electrons : 70MeV/1,836 x 2mA = 76 W
After use for ~20,000 Ah

16. Thermal test on stripper foil using electron linac

17. Temperature variation on stripper foil
Surface temperature on foil vs. e-beam current

18. H- beam losses by Vacuum dissociation and Lorenz stripping
10 MeV
20 MeV
30 MeV
70 MeV
Lorentz stripping
8x10-11
2.4x10-3
Vacuum dissociation
7.6x10-3
1.1x10-2
1.3x10-2
2x10-2
Vacuum level: 1.0 x10-7 torr (N2 equivalent)
From Tianju Zhang (CIAE)

19. Locations of beam losses in ARRONAX cyclotron
1st measurements in march 2013 (Arronax/IBA team)
Exit window for beamline
Radial probe
Machine: Some hot spots
10 to 40 mSv/h:
Extractions windows
Radial probe
Around alpha deflector
No spot > 100mSv/h
Ambient > 3 mSv
No knowledge on built-up yet as 1st measurements
Beamlines:
Specific points along beamlines due to particles losses
Faraday cups
Collimators
impact on maintenance and dedicated strategies
Remove parts of accelerators before consequent build-up
Preliminary snapshot
F. Poirier (CNRS/Arronax), Nov. 2013

20. A plan for the proton cyclotron of RISP
Budget allocated for an ISOL cyclotron at RISP : ~14 M$
By Luciano Calabretta (May 2015)

21. Project schedule for cyclotron installation
~54 months
* Our building construction schedule is tight, so we may need a provision to delay the delivery up to one year.

22. Concluding remarks
We want to immediately start international collaboration to design an A/q=2 cyclotron provided that cyclotron experts agree the RISP plan for ISOL cyclotron is attractive to commercial vendors.
We want to have preliminary quotations from the vendors, which includes the cost, construction period, risk management and so on. plan to make the contract in 2015.
If we have to take a review process in Korea to revise from 70 MeV H- to 40A MeV A/q=2, recommendation letters from international experts would be greatly appreciated.