division accélérateurs
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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 - PowerPoint PPT PresentationTRANSCRIPT
Radioactive Beam Production by
PhotofissionAlex C. Mueller, Accelerator Division, IPN ORSAY, CNRS/IN2P3
(Seminar at the CERN PS-Division, June 13, 2001)
Alex C. Mueller, CERN PS-Div., June 2001, T 1
• 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
Nuclei far from stabilitykey objects in for the nucleosynthesis in the
universe
Alex C. Mueller, CERN PS-Div., June 2001, T 2
• Supernova explosion neutron-rich nuclei
• Gravitational collapse of a massive star to a neutron star
neutron-rich nuclei "neutron-matter" simulating systems
• Nova explosion proton-rich nuclei
Nuclear Forces and the Nuclear Many-Body Problem
effectiveeffectiveNN forceNN force
quarks & gluonsquarks & gluons
free NNfree NNforceforce
nucleonnucleon
light nucleilight nuclei
medium-massmedium-massand heavy nucleiand heavy nuclei
Derivation of the effective NN force
in nuclear medium Derivation of the bare NN force from QCD
The view of the Polish/US theoreticalnuclear physicist Witold Nazarewicz:
Alex C. Mueller, CERN PS-Div., June 2001, T 3
Chemistry and Physics of the
heaviest elements
Alex C. Mueller, CERN PS-Div., June 2001, T 4
Fusion Reactions with neutron-rich beams,like 132Sn, might give acces to this region
The colors in the figure below correspondto the binding energy ("shell stabilization),hence to the life time.In the dark blue region the lifetime mayreach years or more.
Radioactive Beams also have a numberof Applications
(examples from CERN-ISOLDE Webpage)
Alex C. Mueller, CERN PS-Div., June 2001, T 5
The Two Production Methods for Radioactive Beams
and their combination, "RIA" proposed in the US
Alex C. Mueller, CERN PS-Div., June 2001, T 6
"In-Flight"
RIA,combiningISOL & In-Flight
ISOL = Isotopic Separation On-Line
An ISOL facility including post-
acceleration: SPIRAL phase I
Alex C. Mueller, CERN PS-Div., June 2001, T 7
- Driver (GANIL cyclotrons)- Target-ion source system- Post-accelerator cyclotron CIME- I up to 109 pps- Mass range: up to A=100Into operation by summer 2001
Secondary radioactive beam
intensities
Alex C. Mueller, CERN PS-Div., June 2001, T 8
An example for nuclear reaction
cross sections (fission)
Alex C. Mueller, CERN PS-Div., June 2001, T 9
(Calculations: Ridikas, ENAM 98)
Optimising the Production
Alex C. Mueller, CERN PS-Div., June 2001, T 10
•In-Flight : get large high-power accelerator R&D
get N large high-energy > 1 1 GeVGeV
get large high-energy > 1 1
GeVGeV
•ISOL : get large high-power accelerator R&D
get large R&D on target and
ion-sources, like PARRNe
Limits of the ISOL technique:
power deposit in the target
Alex C. Mueller, CERN PS-Div., June 2001, T 11
distance de parcours dans la cible
dE/d
x
Pic de Bragg
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 thermiques :
réacteur nucléaire
235U
Neutrons rapides :
238U utilisable
ISOL at the highest power
levels
Alex C. Mueller, CERN PS-Div., June 2001, T 12
• One stage : direct use of charged particles,
minimize dE/dx (low Z, high E at 1 GeV max. 100 - 200 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
Original Motivation for Spiral-II
Alex C. Mueller, CERN PS-Div., June 2001, T 13
A new driver: d (60 - 200 MeV) with high intensity I = 50 - 200 mA
Dedicated cyclotron or GANIL SSC fission induced by neutrons Fission products accelerated in CIME cyclotron
90Kr, 132Sn I > 101O pps
High Intensity Linacs for future
ISOL Facilities
Alex C. Mueller, CERN PS-Div., June 2001, T 14
The PROTON The PROTON linaclinac driver driver
?? ?? ?? ??
5 MeV100 keV 10 MeV
RFQRFQ
So
urc
eS
ou
rce
DTLDTL
500 MeV100 MeV 200 MeV
= 0.65 = 0.5 = 0.85
1GeV*
DTL, SC DTL, SC cavitiescavities…?…?
LOW ENERGYLOW ENERGYsectionsection
INTERMEDIATEINTERMEDIATEsectionsection
HIGH ENERGYHIGH ENERGYsectionsection
InjectorInjector SCRF SCRF cavitiescavities
* 2GeV possible
• "Generic" lay-out for the EURISOL project
• note similarity with other projected linacs
factory (CERN SPL) nuclear waste trans- mutation Neutron Spallation Source (SNS, ESS) Material Irradiation
Target R&D needed,justification of the PARRNEprogramme for fission fragment production
PARRNe-1(European RTD: IPN-Jyväskylä-Louvain-GANIL-KVI)
Alex C. Mueller, CERN PS-Div., June 2001, T 15
deuteron
converter heatedtarget
secondarypump
spectrometry
cryofinger(12 K)
turbomolecularpump (50l/s)
noblegas
nucleus
neutronflux
PARRNe-2 at the Orsay Tandem
Alex C. Mueller, CERN PS-Div., June 2001, T 16
Targets
Sources
UCx
Molten U
Nier Bernas
Isolde MK5
+
Elements already produced with PARRNe-2 (>100
isotopes)
Alex C. Mueller, CERN PS-Div., June 2001, T 17
PARRNe 23.5 105 132Sn extracted
SPIRAL 21.1 109 132Sn
Before acceleration
Present Rates with PARRNe-2
(here upper fission hump)
Alex C. Mueller, CERN PS-Div., June 2001, T 18
2/2
Production / s/ µA
Stable
102 – 103
103 – 5 103
5 103 – 104
104 – 5 104
5 104 – 105
105 – 5 105
5 105 – 106
106 – 5 106
5 106 – 5 1017
Production à PARRNe
Source d’ions MK5
1µA deuton
26 MeV
Photo-fission:the idea and involved processes
Alex C. Mueller, CERN PS-Div., June 2001, T 19
• Photo-electric effect• Diffusion (Compton, Raleigh)• Pair Production (e+e-) • Nuclear Reactions
•(, f) GDR (Giant Dipolar Resonance) •(, n) •(, 2n)
e-
• Bremsstrahlung• Ionisation • excitation
Cible 238UCxCible 238UCxConvertisseurConvertisseur
Production of photons by Bremsstrahlung and X-section
for photofission
Alex C. Mueller, CERN PS-Div., June 2001, T 20
.
Data compiled by Yu.Ts. OganessianJINR-E7-2000-83 Fission probability:
0.6%/e @ 50 MeV!
e-
Ecm
2
0 2-3o
Distribution of the produced nuclei
in Photofission
Alex C. Mueller, CERN PS-Div., June 2001, T 21
Photofission
e-
+
U
U*
n
FP
FP
Bremsstrahlung
ExcitedNucleus at (GDR)
Fission
The set-up of the CERN experiment
Alex C. Mueller, CERN PS-Div., June 2001, T 22
Collaboration
IPN Orsay
ISOLDE CERN
GANIL
CEA Saclay
Cryogenic finger
UCxTarget
Transport tube
e¯ beam
Photo fission experiment at LIL (CERN)
e-
to cryofinger
W converter
Photon flux
Radioactive noble gases
Location of the converter and the target
Alex C. Mueller, CERN PS-Div., June 2001, T 28
The experiment:cryogenic collection and data
acquisition
Alex C. Mueller, CERN PS-Div., June 2001, T 24
Collection on the cryogenic finger and measurements
3 measurementsConverter @ 8 cmConverter @ 4 cmWithout converter
To the acquisition
PCSUN
COMET
A typical -spectrum from the radioactive decay from the collected
fission fragments
Alex C. Mueller, CERN PS-Div., June 2001, T 25
Results @ CERNand comparison with fast-neutron
data
Alex C. Mueller, CERN PS-Div., June 2001, T 26
Productions de Kr
1,E+04
1,E+05
1,E+06
1,E+07
1,E+08
88 89 90 91 92 93
Nb de masse A
Nb
de
no
ya
ux
/mA
conv 8cm
conv 4cm
sans conv
KVI 80
Without Conv.
KVI 80 MeV D
4 cm Conv.
8 cm Converter
Inspection of the target after irradiation
Alex C. Mueller, CERN PS-Div., June 2001, T 27
SPIRAL-IIand other projects
Alex C. Mueller, CERN PS-Div., June 2001, T 28
Dubna: DRIBS project, under constructionChalk River: theoretical Study by W.T. DiamondSPIRAL-II: here with photofission
Perspectives
Alex C. Mueller, CERN PS-Div., June 2001, T 29
injectorinjector
collimatorcollimator
=1 section=1 section
beambeam dumpdump
analysisanalysis
targettarget
beambeamdumpdump
transport transport lineline
deviationdeviation
100keV100keV 5MeV5MeV 50MeV50MeV
4 SCRF 4 SCRF cavitiescavitiesee--gungun capture SCcapture SC cavitycavity
injectorinjector
collimatorcollimator
=1 section=1 section
beambeam dumpdump
analysisanalysis
targettarget
beambeamdumpdump
transport transport lineline
deviationdeviation
100keV100keV 5MeV5MeV 50MeV50MeV
4 SCRF 4 SCRF cavitiescavitiesee--gungun capture SCcapture SC cavitycavity
Figure 3
20 m long
• 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
Spallation vs. Photofission from
Alex C. Mueller, CERN PS-Div., June 2001, T 30
Comparison Spallation / Photofission
y = 0.1827x 0.1626
y = 0.0759x 0.1446
0
1
10
100
1 000
1.E+12 1.E+13 1.E+14 1.E+15 1.E+16 1.E+17 1.E+18 1.E+19
Neutron Flux (n/s)
Inv
es
tme
nt
Co
st
(ME
uro
)
SPALLATIONPHOTOFISSION
Conclusion of the first part…
Alex C. Mueller, CERN PS-Div., June 2001, T 31