Sugiya Sato

Lifetime measurements and quantum-defect theory treatment of the k 3Πu− state of hydrogen molecule

The experimental and theoretical lifetimes for rovibronic k 3Πu− states of H2 and D2 isotopomers have been investigated over a wide range of vibrational v′ and rotational N′ quantum numbers. Lifetimes have been measured by a delayed coincidence method, combined with direct electron-impact excitation of the ground state molecules and single photon counting techniques to detect induced fluorescence to the a 3Σg+ state. Pronounced pressure-dependence of the experimental lifetimes was observed and properly taken into account. The pure radiative lifetimes of the k 3Πu− states were estimated using theoretical transition dipole moments responsible for the visible k 3Πu→a 3Σg+ transition plus infrared emission on the higher-lying 3Λg states belonging to the 3s,d 3Λg complex. Both the predissociative and autoionization decay rates were predicted by the Fermi-Golden rule based on radial coupling matrix elements for the k 3Πu∼c 3Πu and k 3Πu∼X2Σg+(H2+) pairs of interacting states, respectively. The required electron...

Correlation of lifetimes observed in two vibrational levels of the H2EF1Σg+ state

Abstract The lifetimes were measured for rovibronic levels lying slightly lower than the top of the potential barrier in the H 2 EF 1 Σ g + double-minimum state, with a delayed coincidence method following electron impact excitation from the ground state. Dependence of lifetimes on the rotational levels in a pair of vibrational levels is explained in terms of perturbation caused by rotation–vibration interaction between these levels. Lifetimes of some D 1 Π u and B ′ 1 Σ u + levels were also measured to estimate the cascade effects.

Lifetimes of the k3Πu state in the H2 and D2—experiment and theory

Abstract Lifetimes of H 2 and D 2 k 3 Π u − ν =0–6 levels were measured with a delayed coincidence method combined with electron-impact excitation and single photon counting technique. The lifetime values measured were compared with theoretical values which were calculated assuming competition among radiative, predissociative and autoionization decay processes and by using of a quantum defect method. A reasonable agreement between experimental and theoretical results was achieved.

Observation of Ion Acoustic Waves Excited by Drift Waves in a Weakly Magnetized Plasma

Spontaneous fluctuations excited by drift waves are investigated experimentally in magnetic multi‐pole plasma. The magnetic multi‐pole has been widely used in DP devices and so on. It was observed that the high level of density fluctuations was generated by the drift instability near a magnetic multi‐pole or a dipole magnet. The waves propagate to the middle plasma region forming the envelope train waves.

Separation of Diamagnetic Fine Particles in a Non-Uniform Magnetic Field

Publisher Summary This chapter examines the possibility of the control of the diamagnetic fine particles by the high gradient magnetic field. The possibility of separation and control of diamagnetic substances is shown by means of a fine mesh in accordance with the high gradient magnetic separation method. The chapter introduces the concept of repulsive force to diamagnetic substances and discusses a verification experiment of diamagnetic effect. The control by the electromagnetic forces is considered when the dust particles are charged. Control by the direct electric field is difficult because of the sheath formation in plasma condition. Finally, the chapter presents the magnetic susceptibility of main diamagnetic matter in a tabular form.