Investigation on the DC Stark shifts of strontium autoionization states for isotope-selective resonance ionization

Iwata, Yoshihiro   ; Miyabe, Masabumi   ; Hasegawa, Shuichi*

Following the accident at TEPCO's Fukushima Daiichi Nuclear Power Station, an isotope-selective analysis method using laser resonance ionization has been developed for strontium-90. In this study, we focused on ionization via autoionization states in terms of high isotopic selectivity and ionization efficiency, and the DC Stark shifts caused by the external electric field were measured for these states. It was found that the external electric field in the ionization region has to be of the order of 0.1 V/cm or less to suppress its effect on the observed spectra.