APH N.S., Heavy Ion Physics 13 (2001) 203-205 A New Method to Measure the Neutron Skin HEAVY ION PHYSICS @Akademiai Kiad6 M. Csatlos,' A. Krasznahorkay,' A.M. van den Berg," M.N. Harakeh," S.Y. van der Werf,2 M. Hagemann," M. de HUU,2 H. Akimune," H. Fujimura," M. Fujiwara," K. Hara 5 and T. Ishikawa" 1 MTA, ATOMKI Debrecen, Hungary 2 Kernfysisch Versneller Instituut, 9747AA Groningen, The Netherlands 3 Laboratorium voor Kernfysica Universiteit Gent, B-9000 Gent, Belgium 4 Japan Atomic Energy Research Institute, Advanced Science Research Center 319-1195 Tokai, Japan 5 Research Center for Nuclear Physics, 567-0047 Osaka, Japan Received 20 May 2000 Abstract. Dipole resonances have been excited in 112-124Sn isotopes using (SHe,t) charge exchange reaction at E3He = 177 MeV and the cross sections were related to the neutron-skin thicknesses. The well understood correlation may be used to determine the neutron-skin thicknesses in the future. Keywords: spin-dipole resonance, charge exchange reaction, deduced neutron- skin thicknesses PACS: 24.30.Cz, 21.10.Gv, 25.55.Kr, 27.60.j 1. Introduction The advent of radioactive beams has made it possible to study the structure of nuclei far from the stability. Recently a new possible tool was developed for studying the neutron-skin thickness. It is based on the excitation of the spin dipole resonance (SDR). This resonance can be strongly excited in the charge-exchange reactions. In an experiment the SDR in the Sb isotopes was excited by the eHe,t) reaction at E3He = 450 MeV [1]. It was demonstrated that there exists a correlation between the SDR cross section and the neutron-skin of nuclei. The aim of a new experiment, which was performed at the KVI in Groningen, at E3He = 177 MeV, was to check the method at lower bombarding energy, when the spin-independent part of the nucleon-nucleon interaction is stronger. 1219-7580/01/ $ 5.00 @2001 Akademiai Kiad6, Budapest