Matter radius of the doubly-magic 56Ni measured in a storage ring

The matter radius of the doubly magic Ni-56 was extracted from a measurement of the differential cross section by employing, for the first time, elastic proton scattering in inverse kinematics with a radioactive beam at E-kin = 390.2MeV/nucleon circulating in a storage ring and passing an internal hydrogen gas-jet target with a revolution frequency of around 2MHz. The novel experimental scheme is based on UHV-compatible Si detectors operated as active vacuum windows, which were implemented in the ESR storage ring at GSI. A matter radius < r(m)(2) >(1/2) > 3.74(-0.06)(+0.03) fm was extracted for the doubly-magic self-conjugate nucleus Ni-56.

Automated summary

The matter radius of the doubly magic Ni-56 was determined using elastic proton scattering in inverse kinematics with a radioactive beam at E-kin = 390.2MeV/nucleon. Novel Si detectors operated as active vacuum windows were used in the ESR storage ring at GSI for this experiment. The extracted matter radius < r(m)(2) >(1/2) > for Ni-56 was 3.74(-0.06)(+0.03) fm.