1. Production Cross-Sections of Radionuclides in Proton- and Heavy Ion-Induced Reactions
Strahinja Lukić

2. TARGISOL Winter School 2005 - S. Lukić
Overview
Proton- and heavy ion-induced reactions – basic ideas
Why are proton- and heavy ion-induced reactions important for ISOL applications?
Measurements of production cross-sections for these reactions at GSI
Application example – Determination of ISOLDE extraction efficiencies
TARGISOL Winter School S. Lukić

3. TARGISOL Winter School 2005 - S. Lukić
Basic Ideas
The appropriate reaction is one of the crucial issues for the production of specific ISOL beams.
Specific types of reactions populate specific regions of the chart of the nuclides
TARGISOL Winter School S. Lukić

4. TARGISOL Winter School 2005 - S. Lukić
Basic Ideas
High-energy collision
First stage leading to the formation of an excited prefragment
Deexcitation by particle and γ-ray emission...
... or fission
TARGISOL Winter School S. Lukić

5. TARGISOL Winter School 2005 - S. Lukić
Basic Ideas
During particle emission from heavy nuclei, neutrons are more often emitted than protons.
Spallation and fragmentation populate proton-rich regions of the chart
Fission fragments tend to retain the neutron to proton ratio of the fissioning nucleus.
Fission populates neutron-rich regions of the chart
TARGISOL Winter School S. Lukić

6. Measurements in Inverse Kinematics at GSI
Direct kinematics – focus on what happens to the target:
Prefered concept for the ion beam production
Part of the produced residues stop in the target A B
Inverse kinematics – focus on what happens to the beam
Allows fast residue separation and measurement of almost all residues production cross-sections B A
TARGISOL Winter School S. Lukić

7. Measurements in Inverse Kinematics at GSI
The Fragment Separator
s ≈ 36 m
A/Z identified by (Bρ)2 and ToF in FRS
Z identified by ΔE in ionization chamber
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8. Measurements in Inverse Kinematics at GSI
Residue Identification
136Xe + Pb at 1A GeV
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9. Measurements in Inverse Kinematics at GSI
J. Taïeb et al., NPA 724 (2003) 413
M. Bernas et al., NPA 725 (2003) 213
M.V. Ricciardi, PhD thesis
T. Enquist et al., NPA 658 (1999) 47
Nuclear models benchmarked against these data can be used to predict cross-sections in other energy regions
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10. Production Cross-Sections – Model Calculations
GSI calculation code ABRABLA was benchmarked against the measured data for various reactions
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11. ISOLDE Extraction Efficiencies
The case of production of Br isotopes in UC and Nb targets
Extraction Efficiencies expressed as the Release per Primary production Ratio (RPR) disentangled from the yields
RPR follow the general trend of the secondary isotope half-life
Bromine is created by fission in U and by spallation in Nb
F. Gevaert, maîtrise rapport, Univ. Bordeaux (2002)
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12. TARGISOL Winter School 2005 - S. Lukić
Additional Slides
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13. TARGISOL Winter School 2005 - S. Lukić
Conclusions
The appropriate reaction is one of the crucial issues for the production of specific ISOL beams.
Inverse kinematics experiments at the FRS are an important tool for fundamental measurements related to ISOL applications.
TARGISOL Winter School S. Lukić

14. Production Mechanisms - Fission
Competes as the exit channel in either proton or heavy ion-induced reactions when the target is fissile
Can also be induced by electromagnetic interactions in nucleus-nucleus collisions resulting in the production of very neutron-rich nuclides
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The GSI Facility
Universal linear accelerator (UNILAC)
Heavy-ion synchrotron (SIS)
Fragment separator (FRS)
Experimental storage ring (ESR)
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Fragment Separator
(MUSIC)
A/Z identified by (Bρ)2 and ToF in FRS
Z identified by ΔE in ionization chamber
Z and A are integers and, thus, exactly known →
Velocity precisely determined by (Bρ)1
Relative precision 5·10-4
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17. Charge Determination by MUSIC
136Xe + Pb at 1A GeV
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18. Identification of the Final Residues
136Xe + Pb at 1A GeV
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