Frankfurt 2014 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

HK: Fachverband Physik der Hadronen und Kerne

HK 11: Struktur und Dynamik von Kernen

HK 11.9: Vortrag

Montag, 17. März 2014, 18:45–19:00, HZ 5

Nuclear Excitation by a Strong Zeptosecond Laser Pulse in the Quasiadiabatic Regime — •Adriana Pálffy and Hans A. Weidenmüller — Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg

The ongoing construction of the Nuclear Physics Pillar of the Extreme Light Infrastructure (ELI) offers unprecedented possibilities for nuclear physics experiments. The facility holds promise to deliver in the not-too-distant future coherent gamma ray pulses with energies of several MeV per photon. Coherence strongly amplifies nuclear dipole absorption. If that occurs comparably fast to nuclear equilibration, it leads to the formation of a compound nucleus with excitation energy several hundred MeV above yrast in a so far totally unexplored regime.

A quantitative description of the absorption and equilibration processes requires knowledge of the density of states, so far unavailable for this parameter regime. Our new approach yields approximate analytical expressions for the total and partial level densities [1,2] and makes possible the semiquantitative study of the competition between photon absorption, photon-induced nucleon emission, and neutron evaporation. With neutron evaporation overtaking photon absorption at energies below the saturation of the latter for medium-weight and heavy nuclei, we expect proton-rich nuclei far from the valley of stability to be produced. Experiments at ELI thus promise to shed light on the structure of such nuclei and the time scales and level densities involved.

[1] A. Pálffy and H. A. Weidenmüller, Phys. Lett. B 718, 1105 (2013).

[2] A. Pálffy and H. A. Weidenmüller, Nucl. Phys. A 917, 15 (2013).