Rotation system of magnetic field for the measurement of magnetic moments for neutron-rich isotopes ^41,43S

Rotation system of magnetic field for measurement of magnetic moments for neutron-rich isotopes ^41,43S. The presence of magic numbers (8, 20, 28, etc.), where nuclei become stable, has long been proposed. However, in a certain neutron-rich nuclei region, these magic numbers have been lost. For the magnetic moment measurement of unstable nuclei ^41,43S, which are neutron-rich nuclei in the vicinity of the abnormal nuclei region near N=28, the authors developed a magnetic field rotating device. Using this, they plan to measure the polarization degree as one of the uncertainty factors, independently of the magnetic moment measurement. Magnetic rotation is to measure polarization by changing vertical direction of magnetic field and spins, and a small neodymium permanent magnet is rotated. Although a short period of continuous operation has been confirmed, comprehensive evaluation is planned in the future by assembling a whole apparatus including the accessory devices. The authors evaluated the polarization measurement time of ^41,43S as measurement objects, from the experimental results of RIKEN accelerator facility and RIKEN Projectile Fragment Separator (RIPS), and obtained the results of t(⁴¹S) = 10 min, and t(⁴³S) = 3.3 h. (A.O.)