g-Factor of the excited state in ¹⁰⁹Rh

The authors investigated the g-factor of a low-lying excited state at 225.98 keV in the ¹⁰⁹Rh. This state were populated by the β decay of ¹⁰⁹Ru (T_1/2=34.5 s) and its g-factor was measured using the time-differential perturbed angular correlation method (TDPAC). The ¹⁰⁹Ru beam was provided using proton induced fission reactions and the radio-frequency ion-guide isotope separator on-line (RF-IGISOL). A γ-ray cascade involving the 225.98-keV level was 116.32-(31.80)-225.98 keV cascade shown, and an angular correlation of the 116.32- and 225.98-keV γ-rays were measured. The Larmor precession frequency was derived from the time-patterns of the angular-correlation and the g-factor was obtained as 0.78_-0.03^+0.17. The magnetic moments using I^π=5/2⁺ and 3/2⁺ are derive as 1.95_-0.08^+0.43 and 1.17_-0.07^+0.28 μ_N, respectively. In the single-particle model, a configuration of a ground state on the ¹⁰⁹Rh is π(0g_9/2)⁵. The simplest configurations of the low-lying excited states, spins of which are 5/2⁺ and 3/2⁺, are π(2d_5/2)¹ and π(2d_3/2)¹. These Schmidt values are calculated as 4.793 and -0.124μ_N, respectively, both of which are quite different from the present values. Thus it is suggested that this state is not the single-particle state. (K.F.)