LASER-MICROWAVE DOUBLE-RESONANCE SPECTROSCOPY OF LASER-COOLED BE-9(-FIELD FOR STUDYING UNSTABLE BE ISOTOPES() IONS IN A WEAK MAGNETIC)

Laser-microwave double-resonance spectroscopy of laser-cooled Be-9(+) ions in a linear Paul trap has been performed aiming at the developmen t of both highly sensitive and precise methods to be applied to the un stable isotopes. By the alternative irradiation of laser and microwave radiation (pulsed-wave method), high accuracy of 4 x 10(-7) was obtai ned in the measurement of the ground-state magnetic-dipole hyperfine c onstant (A) of Be-9(+) ion in a weak magnetic field. By the continuous -wave method, high sensitive detection of the microwave resonance was demonstrated. These methods can be complementarily applied to the meas urements of unknown hyperfine constants of the unstable isotopes for s tudying the hyperfine anomaly.