1. Division Accélérateurs
Radioactive Beam Production by Photofission Alex C. Mueller, Accelerator Division, IPN ORSAY, CNRS/IN2P3 (Seminar at the CERN PS-Division, June 13, 2001)
Division Accélérateurs
Introduction
Scientific Motivation
Making Radioactive Beams
Considerations on the Intensities
X-sections for Fission Fragments
The PARRNe R&D Programme
PARRNe-1 at the LEP-injector
Experimental Results
Concluding Outlook
Alex C. Mueller, CERN PS-Div., June 2001, T 1

2. Division Accélérateurs
Nuclei far from stability key objects in for the nucleosynthesis in the universe
Division Accélérateurs
Nova explosion
proton-rich nuclei
Supernova explosion
neutron-rich nuclei
Gravitational collapse
of a massive star to a
neutron star
"neutron-matter"
simulating systems
Alex C. Mueller, CERN PS-Div., June 2001, T 2

3. Division Accélérateurs
Nuclear Forces and the Nuclear Many-Body Problem
Division Accélérateurs
The view of the Polish/US theoretical
nuclear physicist Witold Nazarewicz:
light nuclei
light nuclei
medium-mass
medium-mass
Radioactive
Beam Facilities
and heavy nuclei
and heavy nuclei
nucleon
nucleon
effective
effective
NN force
NN force
ALICE
@LHC
free NN
free NN
force
force
Derivation of the
effective NN force
Derivation of the
in nuclear medium
quarks & gluons
quarks & gluons
bare NN force
CEBAF, ELFE
from QCD
Alex C. Mueller, CERN PS-Div., June 2001, T 3

4. Chemistry and Physics of the heaviest elements
Division Accélérateurs
The colors in the figure below correspond
to the binding energy ("shell stabilization),
hence to the life time.
In the dark blue region the lifetime may
reach years or more.
Fusion Reactions with neutron-rich beams,
like 132Sn, might give acces to this region
Alex C. Mueller, CERN PS-Div., June 2001, T 4

5. Radioactive Beams also have a number of Applications
(examples from CERN-ISOLDE Webpage)
Division Accélérateurs
Division Accélérateurs
Alex C. Mueller, CERN PS-Div., June 2001, T 5

6. Division Accélérateurs
The Two Production Methods for Radioactive Beams and their combination, "RIA" proposed in the US
Division Accélérateurs
"In-Flight"
RIA,
combining
ISOL & In-Flight
ISOL = Isotopic Separation On-Line
Alex C. Mueller, CERN PS-Div., June 2001, T 6

7. An ISOL facility including post- acceleration: SPIRAL phase I
Division Accélérateurs
- Driver (GANIL cyclotrons)
- Target-ion source system
- Post-accelerator cyclotron CIME
- I up to 109 pps
- Mass range: up to A=100
Into operation by summer 2001
Alex C. Mueller, CERN PS-Div., June 2001, T 7

8. Secondary radioactive beam intensities
Division Accélérateurs
Alex C. Mueller, CERN PS-Div., June 2001, T 8

9. An example for nuclear reaction cross sections (fission)
Division Accélérateurs
(Calculations: Ridikas, ENAM 98)
Alex C. Mueller, CERN PS-Div., June 2001, T 9

10. Optimising the Production
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In-Flight : get F large  high-power accelerator R&D
get N large  high-energy > 1 GeV
get e4 large  high-energy > 1 GeV
ISOL : get F large  high-power accelerator R&D
get e1e2e3 large  R&D on target and ion-sources, like PARRNe
Alex C. Mueller, CERN PS-Div., June 2001, T 10

11. Limits of the ISOL technique: power deposit in the target
Division Accélérateurs
Pic de Bragg
distance de parcours dans la cible
dE/dx
Inconvénient des faisceaux intenses de particules chargés :
ralentissement des particules  dépôt d’énergie localisée en fin de parcours (pic de Bragg)
Utilisation des neutrons :
toute l’énergie incidente est dissipée dans la réaction nucléaire
Neutrons rapides :
 238U utilisable
Neutrons thermiques :
 réacteur nucléaire
 235U
Alex C. Mueller, CERN PS-Div., June 2001, T 11

12. ISOL at the highest power levels
Division Accélérateurs
One stage : direct use of charged particles,
minimize dE/dx (low Z, high E at 1 GeV max kW
Two stage : use neutral particles in second stage, i.e. neutrons & photons for neutrons 5 MW of proton beam (like spallation source)
RIA (fragmentation + gas collec-
tion scheme) is also in this class
Alex C. Mueller, CERN PS-Div., June 2001, T 12

13. Original Motivation for Spiral-II
Division Accélérateurs
A new driver: d ( MeV) with high intensity I = mA
Dedicated cyclotron or GANIL SSC
fission induced by neutrons
Fission products
accelerated in
CIME cyclotron
90Kr, 132Sn
I > 101O pps
Alex C. Mueller, CERN PS-Div., June 2001, T 13

14. High Intensity Linacs for future ISOL Facilities
Division Accélérateurs
"Generic" lay-out for
the EURISOL project
note similarity with
other projected linacs
n factory (CERN SPL)
nuclear waste trans-
mutation
Neutron Spallation
Source (SNS, ESS)
Material Irradiation
Target R&D needed,
justification of the PARRNE
programme for fission
fragment production
Alex C. Mueller, CERN PS-Div., June 2001, T 14

15. PARRNe-1 (European RTD: IPN-Jyväskylä-Louvain-GANIL-KVI)
Division Accélérateurs
Alex C. Mueller, CERN PS-Div., June 2001, T 15

16. PARRNe-2 at the Orsay Tandem
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Targets
UCx
Molten U +
Sources
Nier Bernas
Isolde MK5
Alex C. Mueller, CERN PS-Div., June 2001, T 16

17. Elements already produced with PARRNe-2 (>100 isotopes)
Division Accélérateurs
Alex C. Mueller, CERN PS-Div., June 2001, T 17

18. Present Rates with PARRNe-2 (here upper fission hump)
Division Accélérateurs
Alex C. Mueller, CERN PS-Div., June 2001, T 18

19. Photo-fission: the idea and involved processes
Division Accélérateurs
Convertisseur
Cible 238UCx  e-
Photo-electric effect
Diffusion (Compton, Raleigh)
Pair Production (e+e-)
Nuclear Reactions
(, f) GDR (Giant Dipolar Resonance)
(, n)
(, 2n)
Bremsstrahlung
Ionisation
excitation
Alex C. Mueller, CERN PS-Div., June 2001, T 19

20. Production of photons by Bremsstrahlung and X-section for photofission
Division Accélérateurs e- g a
2-3o
Data compiled by
Yu.Ts. Oganessian
JINR-E
Fission probability:
50 MeV! .
Alex C. Mueller, CERN PS-Div., June 2001, T 20

21. Distribution of the produced nuclei in Photofission
Division Accélérateurs
Alex C. Mueller, CERN PS-Div., June 2001, T 21

22. The set-up of the CERN experiment
Division Accélérateurs
Alex C. Mueller, CERN PS-Div., June 2001, T 22

23. Location of the converter
and the target
Alex C. Mueller, CERN PS-Div., June 2001, T 28

24. The experiment: cryogenic collection and data acquisition
Division Accélérateurs
Alex C. Mueller, CERN PS-Div., June 2001, T 24

25. Division Accélérateurs
A typical g-spectrum from the radioactive decay from the collected fission fragments
Division Accélérateurs
Alex C. Mueller, CERN PS-Div., June 2001, T 25

26. Results @ CERN and comparison with fast-neutron data
Division Accélérateurs
Without Conv.
KVI 80 MeV D
4 cm Conv.
8 cm Converter
Alex C. Mueller, CERN PS-Div., June 2001, T 26

27. Inspection of the target after irradiation
Division Accélérateurs
Alex C. Mueller, CERN PS-Div., June 2001, T 27

28. SPIRAL-II and other projects
Division Accélérateurs
Dubna: DRIBS project, under construction
Chalk River: theoretical Study by W.T. Diamond
SPIRAL-II: here with photofission
Alex C. Mueller, CERN PS-Div., June 2001, T 28

29. Division Accélérateurs
Perspectives
Division Accélérateurs
Complete R&D Programme with the LPI front-end and PARRNe-2
SPIRAL-2 (Scientific&Technical Proposal presently under evaluation
The "ultimate" EURISOL electron driver
Figure 3
 20 m long
Alex C. Mueller, CERN PS-Div., June 2001, T 29

30. Spallation vs. Photofission from
Division Accélérateurs
Alex C. Mueller, CERN PS-Div., June 2001, T 30

31. Conclusion of the first part…
Division Accélérateurs
Alex C. Mueller, CERN PS-Div., June 2001, T 31