DEVELOPMENT OF THE BASELINE CORRECTION SYSTEM TO MEASURE HYPERFINE STRUCTURE OF RB ATOMS INJECTED INTO SUPERFLUID HELIUM

We have been developing a laser spectroscopic method for atoms injected into superfluid helium (He II). We aim to measure hyperfine structure splitting which is caused by interaction between nuclei and valence electrons. So far, in the offline experiment, we succeeded in the measurement of hyperfine structure splitting of Rb. However, measurement accuracy and precision were not enough to discuss interaction between Rb and He atoms because of baseline fluctuation caused by instability of the number of atoms supplied by using laser ablation method. In this study, we developed a baseline correction system composed of electro-optic modulator and multi channel scaler, and performed baseline correction experiment by using this system for Rb in He II