Closed-orbit theory is a semiclassical technique for explaining the spectra of Rydberg atoms in external fields. Using the closed-orbit theory and classical perturbation theory, we calculate the scaled recurrence spec...Closed-orbit theory is a semiclassical technique for explaining the spectra of Rydberg atoms in external fields. Using the closed-orbit theory and classical perturbation theory, we calculate the scaled recurrence spectra of Lithium atom in magnetic field plus a weak perpendicular electric field. The results show when the crossed electric field is added, the recurrence spectra are weakened greatly. As the scaled electric field f increases, the peaks of the recurrence spectra lose strength. Some recurrences are very sensitive and fall off rapidly as f increases; others persist till much higher f . As the electric field is stronger, some of the peaks revive. This phenomenon, caused by the interference among the electron waves that return to the nucleus, can be computed from the azimuthal dependence of the classical closed orbits.展开更多
Nose event,which names after the nose-like shape of structures in ion spectrograms observed by satellite in the inner magnetosphere,refers to the deep inward penetration of ions from magnetotail at discrete energy ban...Nose event,which names after the nose-like shape of structures in ion spectrograms observed by satellite in the inner magnetosphere,refers to the deep inward penetration of ions from magnetotail at discrete energy bands.Nose events have been studied extensively both with observations and simulations since first discovered in 1970s.In this study we use the UBK method to model the different L-shell penetration characteristics for a multi-band nose event observed by Cluster/CODIF on April 11,2002.The modeled open-closed orbit separatrices are generally smaller than the observed L-shell penetrations for outbound crossing;the difference varies from 2.02 to 0.62 R E for different energy channels of H + bands and from 1.88 to 1.10 R E for O + band.The average difference is 1.46 R E.The separatrices for the inbound crossing are generally larger than those of outbound crossing and are more consistent with the observed L-shell penetration depths.The modeled open-closed orbit separatrices are smaller than the observed L-shell penetrations for 6.5-17.1 keV energy channels of H + bands but larger for 4.0-5.1 keV(due to closed banana orbits region) and 21.7-35.2 keV(due to energy increasing) energy channels of H + bands.For O + band,the difference between the modeled open-closed orbit separatrix and observed L-shell penetrations of 4.6 keV energy channel is larger(due to closed banana orbits region),the difference of 7.4 keV energy channel is smaller.The overall average difference is 0.043 R E for nose structures of inbound crossing.The discrepancies between the model and observation may come from the magnetic field and electric potential models we used.The formation of multi nose event and relations to the observed plasma flow vortices are discussed,the local intense E Y may relate to the formation of the observed multi nose structures.展开更多
文摘Closed-orbit theory is a semiclassical technique for explaining the spectra of Rydberg atoms in external fields. Using the closed-orbit theory and classical perturbation theory, we calculate the scaled recurrence spectra of Lithium atom in magnetic field plus a weak perpendicular electric field. The results show when the crossed electric field is added, the recurrence spectra are weakened greatly. As the scaled electric field f increases, the peaks of the recurrence spectra lose strength. Some recurrences are very sensitive and fall off rapidly as f increases; others persist till much higher f . As the electric field is stronger, some of the peaks revive. This phenomenon, caused by the interference among the electron waves that return to the nucleus, can be computed from the azimuthal dependence of the classical closed orbits.
基金supported by the National Natural Science Foundation of China (Grant Nos. 40831061,41074117)
文摘Nose event,which names after the nose-like shape of structures in ion spectrograms observed by satellite in the inner magnetosphere,refers to the deep inward penetration of ions from magnetotail at discrete energy bands.Nose events have been studied extensively both with observations and simulations since first discovered in 1970s.In this study we use the UBK method to model the different L-shell penetration characteristics for a multi-band nose event observed by Cluster/CODIF on April 11,2002.The modeled open-closed orbit separatrices are generally smaller than the observed L-shell penetrations for outbound crossing;the difference varies from 2.02 to 0.62 R E for different energy channels of H + bands and from 1.88 to 1.10 R E for O + band.The average difference is 1.46 R E.The separatrices for the inbound crossing are generally larger than those of outbound crossing and are more consistent with the observed L-shell penetration depths.The modeled open-closed orbit separatrices are smaller than the observed L-shell penetrations for 6.5-17.1 keV energy channels of H + bands but larger for 4.0-5.1 keV(due to closed banana orbits region) and 21.7-35.2 keV(due to energy increasing) energy channels of H + bands.For O + band,the difference between the modeled open-closed orbit separatrix and observed L-shell penetrations of 4.6 keV energy channel is larger(due to closed banana orbits region),the difference of 7.4 keV energy channel is smaller.The overall average difference is 0.043 R E for nose structures of inbound crossing.The discrepancies between the model and observation may come from the magnetic field and electric potential models we used.The formation of multi nose event and relations to the observed plasma flow vortices are discussed,the local intense E Y may relate to the formation of the observed multi nose structures.
