Transcript Document 7648437

Sp i r a l2
RIB production with SPIRAL 2
1. Versatile and evolutive
2. Fission fragments with D beam
fusion-evaporation with heavy ions
Goal > 1013 fissions/s
3. Basic configuration :
 Fission fragments produced by n-induced fission
 Converter d-n with a carbon wheel
 UCx fissile target - low or high density (Gatchina)
 Possibility to couple different ions sources (1+)
 1+/n+ (charge breeder) approach
D
C
1+
UCx
IS
Rencontre de Moriond, 17-22 March
n+
ECR
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Sp i r a l2
Fission yields
with converter ...
d
4.5 mA 1013 f/s =2.3g/cm2 V=240cm3
5 mA 5.1013 f/s =11g/cm2 V=240cm3
n
UCx
5 mA 2.1014 f/s =11g/cm2 V=1000cm3
Fission of 239U Ex= 20 MeV
6kW (limit)
40 MeV deuteron, 5 mA  200 kW dissipation in the converter
without converter ...
d,3,4He,...
UCx
0.15mA 5.1012 f/s 6kW
Fission of 240Pu,... Ex≥ 50 MeV
acces to a wider mass region
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Fission yields (low density and with converter)
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d (40 MeV, 4.3 mA) + C + UC (2.3 g/cm3, 363 g)
on target
x 10-2 - 10-3
towards experiment
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Example : production from D beam
1012
 Sn isotopes
1011
D 4 mA on C with UCx low
density target (1013 fissions/s).
Yield (pps)
1010
UCx target
Produced in the ISOL target
109
108
107
After acceleration
106
IS
105
104
127
Sn
128
129
130
131
132
133
134
135
A
Efficiencies for Sn isotopes
T1/2 (s) Diff.
132
133
40
1.4
Eff.-t
0.31 0.83
0.065 0.16
M.G. Saint-Laurent
Eff.-tube 1+
1+/n+
Acc.
Total
0.99
0.86
0.04
0.04
0.5
0.5
1.5e-3
5.4e-5
0.3
0.3
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Production from Heavy Ion Beams
Primary Heavy Ion beams at 14.5 A.MeV of 1 mA, up to Ar
 neutron deficient RIB
p,d,…,HI
Fusion-evaporation and transfer reactions
residues produced
by thick target method (like ISOL@GSI)
Thick
target
example
58Ni
+ 50Cr  100Sn 1+ ~1 pps
Spectroscopy of N=Z A≈100
 neutron rich RIB
Thin
target
HI
Fusion-evaporation residues produced by thin
separator
target method (In-Flight)
example
28Ni
+ 58Mg  80Zr 1+ ~ 3 x 104 pps
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Regions of the nuclear chart covered by ...
3. N=Z
5. Transfermiums
In-flight (Z=106, 108)
4. Fusion reaction
with exotic beam
1. Fission products
2. High Ex fission products
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Target & Ion Source : the Plug solution
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rotating C wheel
primary beam
(deuterons)
2 m concrete
 dose rate
< 7.5 Sv/h
Plug housing C converter
and UCx target
dose rate 32 Sv/h at 1 m and 34 mSv/h after 1 year
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exotic beam
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Detail of the rotating wheel
UC2 target
Ti support
R = 385 mm
Beam
size: 10 x 25 mm
Carbon « standard »
First study
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DRIVER
Source
Injector
Linear accelerator
14.5 A.MeV ions
40 MeV deuterons
•
Must be an evolutive and versatile machine
•
Optimised for q/A=1/3 ions and must accelerate D+ (q/A=1/2)
•
No stripper, to make a direct profit of the ECR sources evolutions
for heavy ions, as far as beam energy is concerned
•
1 mA for ions (up to Argon) and 5 mA for deuterons
•
Injector: RFQ with a 100% Duty Cycle
Exit Energy: 0.75 A.MeV - 1.5 A.MeV (according to the frequency)
•
LINAC: Independant Phase Superconducting Cavities
based on QWRs and/or HWRs up to 40 MeV or 14.5 A.MeV
Frequency : 88 MHz and 176 MHz
or 176 MHz for the whole linac
gradient ~ 6-8 MV/m ( = Vacc /   ) ~ 30-40 resonators
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Main driver components
Deuteron Source ex. SILHI-type
(permanent magnets)
QWR Argonne
example of ACCEL cryostat
(4 cavities, 2 solenoids)
SC Solenoid
+ steering coils
+ active screening
RFQ (Cu plated SS version)
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Primary Sources R&D
 deuterons (5 mA) : “downgrade” of SILHI source or micro-phoenix or ...
 heavy ions q/A=1/3 (1 mA)
cw mode, voltage = 60 kV,  < 200  mm mrad
state-of-the-art :
18O
6+
1 mA
36Ar
12+
0.2 mA
 High Frequency & high B
1. A fully superconducting ECRIS (close to the GYROSERSE project)
Bmax = 4 T; Brad = 3 T; large ECR zone, F = 28 GHz, and possibly above
2. A compact source, with lower magnetic field & higher power density (A-PHOENIX)
technology based on HTS coils and permanent magnets Bmax = 3 T; Brad= 1.6 T
SERSE at LNS (14-18 GHz)
PHOENIX (28 GHz)
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Low Energy Beam Transfer (LEBT)
Goal :
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to transport and to match and 2 types of beam
to RFQ with very low loss
energy : 20 keV/n
D+ (5 mA, 40kV) q/A=1/3 (1mA, 60kV)
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Linac architecture
Beam Dynamics studies determine the optimal choice of
 linac frequency
 resonator types
 transition energies (RFQ output, geometric betas)
 Nb of resonators / cryostat,
etc ...
and should also accelerate heavier ions (q/A~1/6)
2 options : 88/176 MHz or 176 MHz for the whole linac
pro’s and con’s
88 MHz requires QWRs  easier fabrication and cleaning
but dipole fields only partially compensated
176 MHz only  only HWRs could be used but more
dissipation in the RFQ, requires higher RFQ output energy
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Different technological solutions for the RFQ
Sp i r a l2
4-rod RFQ, IH-type RFQ  cheaper but low-frequency
IAP Frankfurt
4-vane RFQ  cw operation & high transmission
classical brazed Cu
88 or 176 MHz
Cu plated SS
88 MHz
separated functions
88 MHz
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with rf joints
88 or 176 MHz
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Phase space at the RFQ output
Ex. 88 MHz 4-vane
aperture = 8 - 10 mm
Length = 5m Energy = 0.75 A.MeV
vane voltage = 100 -113 kV
Transmission 99,95% (1/2)
Modulation 1-2
99,93% (1/3)
1/3
1/2
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Resonators
Legnaro-type QWR
Argonne_type QWR and HWR
(with field asymmetry compensation)
~ 40 resonators at 6 MV/m ~ 30 resonators at 8 MV/m
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Beam dynamics in the SC linac
2 essential rules to avoid
 dilution + beam loss :
1. phase advance < 90°
2. long. & trans. matching between tanks
 favours large Nb cavities / tank
solenoid instead of quad focusing
phase advance too large !
1 solenoid / cavity at low energy to keep
the beam size < the cavity aperture (30 mm max)
Bz < 7-8 T to keep
classical technology
NbTi SC solenoid
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Schematic lay-out (1)
CIME
Q/A= 1/3
ion source
Deuteron
Source
charge breeder
1+ / N+
Deuteron
Target-Source Heavy ions
system
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40 MeV
15 MeV/u
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Schematic lay-out (2)
post-accelerator CIME
Low energy RIB
stable heavy ions
Injection to CIME
ECR Sources
(d and q/A=1/3 ions)
SC LINAC
RFQ
40 MeV and 14.5 A MeV
F. Daudin
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GANIL expansion
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Time schedule
First
Studies
……………
Option
Choice
2001
2002
APD ~ 2 years
Nov 2004
2003
2004
2005
2006
2007
2008
APS
APD
Construction
CONSTRUCTION
FIRST
DECISION
BEAMS
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Long-term future (1)
can be used as a post-accelerator
with future upgrade in energy
Energy upgrade
SPIRAL 2
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Long-term future (2)
or can be used as the low energy part
of a future high energy driver
postaccelerator
production
Energy upgrade
SPIRAL 2
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