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On the two-proton emission for Fe45 - a new type of radioactivity

J. Giovinazzo·B. Blank·M. Chartier·S. Czajkowski·A. Fleury·M. J. Lopez Jimenez·M. S. Pravikoff·J. -C. Thomas·F. De Oliveira Santos·M. Lewitowicz·V. Maslov·M. Stanoiu·R. Grzywacz·M. Pfutzner·C. Borcea·B. A. Brown
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Abstract

In an experiment at the SISSI-LISE3 facility of GANIL, the decay of the proton drip-line nucleus Fe45 has been studied after projectile fragmentation of a Ni58 primary beam at 75 MeV/nucleon impinging on a natural nickel target. Fragment-implantation events have been correlated with radioactive decay events in a 16x16 pixel silicon strip detector on an event-by-event basis. The decay-energy spectrum of Fe45 implants shows a distinct peak at (1.06+/-0.04)MeV with a half-life of T1/2 = (4.7+3.4-1.4)ms. None of the events in this peak is in coincidence with beta particles which were searched for in a detector next to the implantation detector. For a longer correlation interval, daughter decays of the two-proton daughter Cr43 can be observed after Fe45 implantation. The decay energy for Fe45 agrees nicely with several theoretical predictions for two-proton emission. Barrier-penetration calculations slightly favour a di-proton emission picture over an emission of two individual protons and point thus to a He2 emission mode.

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J. Giovinazzo, B. Blank, M. Chartier, S. Czajkowski, A. Fleury, M. J. Lopez Jimenez, M. S. Pravikoff, J. -C. Thomas, F. De Oliveira Santos, M. Lewitowicz, V. Maslov, M. Stanoiu, R. Grzywacz, M. Pfutzner, C. Borcea, B. A. Brown. 2002-05-22. On the two-proton emission for Fe45 - a new type of radioactivity. https://doi.org/10.1016/s0375-9474(03)01403-9

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