Speaker
Description
Projectile fragmentation is universal and very powerful tool for production of exotic nuclei, including neutron-deficient species. The yield estimates of neutron-deficient trans-Pb nuclei lack benchmark against experimental data in terms of production cross sections. Therefore, measurements of projectile fragmentation cross-sections using the 1 AGeV 238U primary beam on a beryllium target have been carried out at the GSI Fragment Separator (FRS) in FAIR Phase-0 programme.
Gathering cross-section data towards and beyond the borders of known nuclei is important for tests and further development of fragmentation models. It is also important for planning of future experiments at FAIR Super-FRS. Most of the existing data originate from a measurement of 238U at 1 AGeV on a proton target [1]. Another study [2] measured fragmentation cross section of 238U + 9Be reaction at 1 AGeV. This study provides the possibility compare to theoretical models down to cross section of about 1 nb, but is limited to Th and Pa isotopes. There is a large mismatch when comparing the cross-section predictions of the EPAX or ABRABLA codes with scarce data. This is profound especially for the trans-Pb neutron-deficient nuclei.
To provide a reliable dataset of fragmentation reaction cross sections, measurements at FRS are presented. These data contain a comprehensive set of cross sections of neutron-deficient isotopes ranging from Pb to U. In the present contribution, the methodology and results will be presented. The measurements form a part of larger programme at FRS to map production cross sections in projectile fragmentation.
[1] Taïeb et al., Nucl. Phys. A 724 (2003) 413
[2] Kurcewicz et al., Nucl Phys A 767 (2006) 1