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Introduction
To extend the study of the structure of nuclei far from stability
 Production of RIB's via the fission process induced
- either by fast neutrons from a C converter in a UCx target
goal >1013 fissions/s
- or by direct bombardment of fissile material
 Production of heavy ion beams for fusion-evaporation physics
C
D
1+
n+
UCx
IS
ECR
Basic configuration for RIB production :
 high intensity D primary beam on a D-N Converter with a Carbon wheel
 fission fragments produced by N-induced fission of a
UCx fissile target - low or high density (Gatchina)
 Different ion sources coupled (depending on ionization efficiency)
 Isotopes bred to higher charge state for proper post-acceleration
Le projet SPIRAL-II, 5 octobre 2003, Porquerolles
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Fission yields
with converter and ~ 5 mA primary beam...
d
n
UCx
Fission of 239U
Ex= 20 MeV
low density
 = 2.3 g/cm3
1013 f/s
high density
5.1013 f/s
2.1014 f/s
V = 240 cm3
 = 11 g/cm3
V = 240 cm3
V = 1000 cm3
200 kW dissipation in the converter
5 mA - 40 MeV deuteron
300 W
6 kW (limit)
power deposited
in the target
without converter and ~ 0.15 mA primary beam...
d,3,4He,...
Fission of 240Pu
Ex≥ 50 MeV
UCx
5.1012 f/s
6 kW
acces to a wider mass region
Le projet SPIRAL-II, 5 octobre 2003, Porquerolles
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Regions of the nuclear chart covered by
primary beam:
 deuterons
 heavy ions
4. N=Z
ISOL (thick target)
5. Transfermiums
In-flight (Z=106, 108)
2. Fusion reaction
with exotic beam1
Z
1. Fission products (w/ converter)
3. High Ex fission products (w/o converter)
N
Le projet SPIRAL-II, 5 octobre 2003, Porquerolles
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Physics with fast neutrons
Material irradiation
SPIRAL2 will deliver  1015 neutrons /s peaked at 14 MeV
ideal spectrum for material studies in future fusion machines
available before IFMIF and at reduced cost
Pulsed neutron beam (future option)
measurement of cross-sections for fission and (n,xn) reactions
neutron energy inferred from time of flight technique (ToF)
with 1% resolution for 10 m long beamline
Le projet SPIRAL-II, 5 octobre 2003, Porquerolles
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Schematic Layout
Charge breeder
1+ / N+
α
CIME
Source q/A=1/3
Source
Separator deuterons
TIS Station
Stable ion
beams
1.
2.
3.
4.
Driver
Target - Ion Source Station
Secondary Beam Lines
High Energy Radioactive Beam Lines
Irradiation
Neutrons
14 MeV
Le projet SPIRAL-II, 5 octobre 2003, Porquerolles
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Charge breeder
1+ / N+
α
CIME
1.
2.
3.
4.
Source q/A=1/3
Source
deuterons
Driver
Target - Ion Source Station
Secondary Beam Lines
High Energy Radioactive Beam Lines
Le projet SPIRAL-II, 5 octobre 2003, Porquerolles
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Facility layout
Le projet SPIRAL-II, 5 octobre 2003, Porquerolles
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Simultaneous beams at GANIL
Multi-Faisceaux
easier with direct lines
CIME  salles G1-G2
3
séparateur
1+/n+
1
4
5
2
Example (5 beams)
SPIRAL2 : 40 MeV D+ onto ECS
1) Low energy RIB (LIRAT)
2) 6 A.MeV RIB
CIME  VAMOS / EXOGAM
Standard GANIL
3) stable beam/RIB at
50-100 A.MeV (CSS ’s)
4) 1 A.MeV stable (IRRSUD)
5) 8-10 A.MeV stable (SME)
Le projet SPIRAL-II, 5 octobre 2003, Porquerolles
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Converter
SPIRAL2
PSI
200 kW
60 kW
Diameter
1m
0.45 m
Pradiation
53 W/cm2
35 W/cm2
1750°C
1527°C
Pmax
T max
beam spot Ø 40 mm (parabolic distrib)
thickness = 10 mm
rotation speed < 600 trs/mn
in case of C wheel failure :
target protection =
Carbon foil between wheel and target
 70 ms to switch the beam off
(time delay for 1000° to 3200°C increase)
Homogeneous and Bragg model energy deposition
Le projet SPIRAL-II, 5 octobre 2003, Porquerolles
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Targets
Geometry of the UCx target has been studied by calculating the optimum location
taking into account the distribution of the neutron flux coming from the converter.
3 geometries giving > 1013 fissions/s
complete effusion simulations in progress
19 series of 61 disks UC3 density 2.3 g/cm3
Ø15, thickness = 1, spacing = 0.3
Example of configuration
Le projet SPIRAL-II, 5 octobre 2003, Porquerolles
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Ion Sources
Four types of ion sources considered for the project :
 ECR ion source (gaseous elements such as the noble gases)
 FEBIAD source (Forced Electron Beam for Ionization by Arc Discharge)
(less volatile elements)
 thermo-ionisation source (alkalis and some rare earth elements)
 laser source (non-volatile elements such as metallic ones and high selectivity)
prototype of ECR ion source (demanding in terms of room & auxiliary equipment)
adaptation of the surface ionisation source developed at TRIUMF
development of a FEBIAD prototype for pushing up the usual lifetime limitation
Le projet SPIRAL-II, 5 octobre 2003, Porquerolles
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Plugs
Adaptation of the plug technology developed at TRIUMF
Shielding of all radio-sensitive elements, like pumps (32 Sv/h at 1 m after 3 month irradiation))
Manual disconnection of the module before handling for storing or dismantling
Size of biological shielding determined by dose rate calculations < 10 μSv/h at the top)
(basic, complete, in the vacuum tank)
Service cap
Shielding plug
1.25 m steel +
1.50 m concrete
Containment
Box
D-beam axis
RIB axis
Le projet SPIRAL-II, 5 octobre 2003, Porquerolles
Shutter Valve
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Plugs (2)
couvercle béton
passages
avec câble HT
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Driver
The driver must accelerate beams
 of high power (200 kW deuteron beam power)
 different ion species and mass-to-charge ratios (deuterons as well as heavier ions
of mass-to-charge ratio A/q=3 and up to A/q=6 in a later stage)
 with a high output energy flexibility (from 40 MeV deuteron energy down to low
energies, as low as the RFQ exit energy)
“Independently Phased Superconducting Linac” : provides a safe cw operation and
high flexibility in the acceleration of different ion species and charge-to-mass ratios
Short cavities: very wide velocity acceptance  optimisation of the output energy
for each ion specie by readjusting the RF phases of each cavity
Ein
[keV/u]
Eout
[MeV/u]
 rms [.mm.mrad]
z rms [.deg.MeV]
Intensity
[mA]
A/q = 2
20
20
0.2
0.05
5
a) conservative  expected from sources
A/q =3
20
14.5
0.4
0.12
1
b) z at RFQ output
Le projet SPIRAL-II, 5 octobre 2003, Porquerolles
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Driver layout : reference design
0
6m
Sources + LEBT
11 m 15 m
RFQ
MEBT
88 MHz =0.07
QWR (12 mod x 1 cav)
28 m
88 MHz =0.12
40 m
QWR (6 mod x 2 cav)
88 MHz
Source D+
RFQ 1
Eacc = 6-7 MV/m
RFQ 2
Source q/A=1/3
Source q/A=1/6
Le projet SPIRAL-II, 5 octobre 2003, Porquerolles
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D+ sources: SILHI-type & μPhoenix
Water cooling
UHF injection
Hexapolar magnet
Monogap
extraction
Gas injection
Plasma
electrode
Magnet for
axial field
Hybrid magnet for
Hexapolar and Axial field
ex: MicroPHOENIX 10 GHz
norm. rms  = 0.084 .mm.mrad
for 5 mAe D+ extracted @ 38 kV
Le projet SPIRAL-II, 5 octobre 2003, Porquerolles
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Heavy Ions Sources R&D
A/q=3 ion source :
state-of-the-art in ECR sources: 1 mA 18O6+ and 0.2 mA 36Ar12+
High confinement fields (Br  2-3 T) and high frequency (f > 28 GHz) required
 Two options are explored, based on
 a fully superconducting ECR source
 a combination of permanent and high temperature superconducting magnets
European research activity “Ion Sources for Intense Beams of Heavy Ions” (ISIBHI)
SERSE at LNS 14-18 GHz
PHOENIX 28 GHz
Le projet SPIRAL-II, 5 octobre 2003, Porquerolles
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Beam Dynamics (2)
cavity aperture
1/3
Results :
suitable emittance growths
safety margin [bore radius / max beam amplitude] 1.8 for ions 2.5 for deuteron
next step :
 systematic start-to-end simulations including all effects and alignment errors
Le projet SPIRAL-II, 5 octobre 2003, Porquerolles
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Warm intertank space
Quads + Diagnostics : trade-off between BD and Diag people !
Le projet SPIRAL-II, 5 octobre 2003, Porquerolles
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RFQ
•
Accelerates in CW mode:
 D+ beam up to 5 mA
up to 0.75 – 1 MeV/u
 q/A=1/3 ions up to 1 mA
•
To allow hands on maintenance:
 99% of transmission w/o errors
 97% min with all combined errors
•
The construction takes into account:
6.5 m
5m
 Non constant voltage and R0 profile
  1% on the voltage law
  1/10th mm vane tips displacement
 Minimum price
Le projet SPIRAL-II, 5 octobre 2003, Porquerolles
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RFQ : 4-vane from tube and rf joints
safe cw operation (lowest peak power density < 6W/cm2)
highest transmission
• Only mechanical assembly
• from a low cost copper tube
• Possible change of the vanes
• w/o brazing nor welding  RF join
Le projet SPIRAL-II, 5 octobre 2003, Porquerolles
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Resonators
Legnaro-type QWR
Argonne-type QWR and HWR
(with field asymmetry compensation)
Le projet SPIRAL-II, 5 octobre 2003, Porquerolles
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QWR : cavity shape optimization
Goals for 8 MV/m (E/) operation :
 lower Epk / Eacc ~ 5 → Epk ≈ 40 MV/m
 enlarge curvature radius of drift tube
 lower Bpk / Eacc ~ 10 mT/MV/m → Bpk ≈ 80 mT
 enlarge stem diameter
Cavity stiffening :
Stem  conical shape
Top
 rounded shape
Power coupler location :
Coupler mounted on removable bottom plate
Electric coupling in low |H| area
 Qext as low as 7 104
50 ohms coaxial line Ø = 30 mm
Le projet SPIRAL-II, 5 octobre 2003, Porquerolles
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R&D program (1)
Goal :
to develop and test the most critical components to validate
the chosen technology before the construction phase
Provisional budget for this 2-year R&D program = 850 k€
For the accelerator :
 One RFQ module (1 meter long)
test at full RF power in summer 2004 with a 88 MHz-40 kW power source
 Two 176 MHz SC resonators, one QWR + one HWR
to validate fabrication, preparation and mounting procedures
to compare performances of both cavity types (tests before the end of 2004)
 Two high power couplers (in the range 10-20 kW)
fabrication at the end of 2004 and test in 2005.
 One 10 kW solid state amplifier module for the SC resonators
collaboration with other laboratories under study
goal : prototype tested at the end of 2004
Le projet SPIRAL-II, 5 octobre 2003, Porquerolles
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R&D program (2)
For the target-ion source system :
 Target R&D already started within a collaboration with Gatchina
goal : to compare the performances of low and high density UCx targets
besides, R&D on low density UCx pellets of different sizes and shapes
 Design and developments of the target oven
graphite oven prototypes tested to study temperature uniformity and mechanical
resistance for a long operation period
 FEBIAD ion source tests to demonstrate the reliability of the cathode for a long
period operation
 ECR ion source tests to demonstrate the feasibility of a prototype
using magnetic coils
Le projet SPIRAL-II, 5 octobre 2003, Porquerolles
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Time-schedule for Safety Authorities
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Project organization
DSM
Institutes
IN2P3
Steering Committee
TAC Technical
SAC Scientific
Advisory
Committee
Advisory
Committee
Project Study Group
Project Management
Physics/Exp.
Accelerator
Target stations
Beam Lines
D+ Sources
Ion Sources
RFQ
Cryomodule A/B
Beam Dynamics
RF
Cryogenics
Integration
Converter
Targets
Ion Sources
Hot Cell
Plug & Handling.
Separator
Calculs lignes
Magnets
CIME post-acc.
Charge booster
1+/n+
Specific Techn.
Nuclear physics,
atomic,
astrophysics ..
Conv. Facilities Safety Radiation
Diagnostics
Buildings
Vaccum
Elec. Power
Control systems Power Supplies
Refrig. / Fuides
Waste
Tech. Support
Studies
- Safety
- Rad. shielding
Documents Prep.
-DOS, RPS,
DAM, DAR
Joint Laboratories
Le projet SPIRAL-II, 5 octobre 2003, Porquerolles
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Collaborations
Argonne
UK ??
Gatchina
Louvain ??
Triumf
LPC
GSI ??
SPR
GANIL
DAPNIA
IRES
DPII
IPNO
CSNSM
Isolde ??
DIF
CENBG
ISN
CENG
Legnaro
Le projet SPIRAL-II, 5 octobre 2003, Porquerolles
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