0000000000324393
AUTHOR
Hirokane Kawakami
A simple method for counting the number of trapped ions in an ion trap
The number of stored Ca\(^+\) ions in an ion trap was measured optically by utilizing the metastable states. All the ions trapped are first pumped into the metastable \(D\) states. The ions in the metastable \(D\) states are transferred to the ground \(S\) state via the \(P\) state by exciting a \(D\rightarrow P\) transition. Each ion then emits one photon through a subsequent \(P\rightarrow S\) spontaneous emission. Thus, the number of photons is the same as the number of trapped ions initially in the metastable states. When a fraction of all the stored ions are pumped into the metastable states, the method is still applicable if the fraction of the ions is known.
Laser-microwave spectroscopy of the hyperfine structure of 9Be for the investigation of unstable Be isotopes
Abstract For an investigation concerning the nuclear magnetic moments and their distributions in the nuclei of 7,11Be, an experimental project using laser-microwave double resonance spectroscopy for trapped ions is under progress at INS. Laser cooled ion crystals consisting of a few 9Be+ ions were observed and the ground state hyperfine splitting of 9Be+ was measured with a precision of 10−5. Experiments on the unstable isotope 7Be have been started.