Above-Barrier Coulomb Excitation of ⁷⁸Kr with the JANUS Setup

The JANUS setup [1] has been used for sub-barrier projectile Coulomb excitation measurements with rare and stable isotopes [1-8] at Michigan State University since its commissioning with ⁷⁸Kr beam Coulomb-excited on a ²⁰⁸Pb target [1]. In the same experiment, JANUS was also used to explore the population of excited states in the inelastic scattering of ⁷⁸Kr beam on ⁴⁸Ti target at an energy that is 150% of the Coulomb barrier. In this regime of “unsafe” Coulomb excitation, higher-energy and higher-spin states were shown to be excited [9]. The angular coverage and particle-gamma detection scheme of JANUS allowed to track how the population patterns change for the excited states of ⁷⁸Kr when entering such a highly “unsafe” regime. The results for ⁷⁸Kr will be presented and the potential for using JANUS for spectroscopy following unsafe Coulomb excitation will be discussed.

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