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

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 10.05.2019 TARGISOL Winter School 2005 - S. Lukić

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 10.05.2019 TARGISOL Winter School 2005 - S. Lukić

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 10.05.2019 TARGISOL Winter School 2005 - S. Lukić

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 10.05.2019 TARGISOL Winter School 2005 - S. Lukić

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 10.05.2019 TARGISOL Winter School 2005 - S. Lukić

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 10.05.2019 TARGISOL Winter School 2005 - S. Lukić

Measurements in Inverse Kinematics at GSI Residue Identification 136Xe + Pb at 1A GeV 10.05.2019 TARGISOL Winter School 2005 - S. Lukić

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 10.05.2019 TARGISOL Winter School 2005 - S. Lukić

Production Cross-Sections – Model Calculations GSI calculation code ABRABLA was benchmarked against the measured data for various reactions 10.05.2019 TARGISOL Winter School 2005 - S. Lukić

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) 10.05.2019 TARGISOL Winter School 2005 - S. Lukić

TARGISOL Winter School 2005 - S. Lukić Additional Slides 10.05.2019 TARGISOL Winter School 2005 - S. Lukić

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. 10.05.2019 TARGISOL Winter School 2005 - S. Lukić

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 10.05.2019 TARGISOL Winter School 2005 - S. Lukić

TARGISOL Winter School 2005 - S. Lukić The GSI Facility Universal linear accelerator (UNILAC) Heavy-ion synchrotron (SIS) Fragment separator (FRS) Experimental storage ring (ESR) 10.05.2019 TARGISOL Winter School 2005 - S. Lukić

TARGISOL Winter School 2005 - S. Lukić 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 10.05.2019 TARGISOL Winter School 2005 - S. Lukić

Charge Determination by MUSIC 136Xe + Pb at 1A GeV 10.05.2019 TARGISOL Winter School 2005 - S. Lukić

Identification of the Final Residues 136Xe + Pb at 1A GeV 10.05.2019 TARGISOL Winter School 2005 - S. Lukić