The Ramsey fringes on the ground-state hyperfine transition of ^(199)Hg^(+)(ΔF=1,ΔmF=0)ions trapped in a hyperbolic Paul trap are firstly observed with the method of time-separated oscillatory fields.The full width ...The Ramsey fringes on the ground-state hyperfine transition of ^(199)Hg^(+)(ΔF=1,ΔmF=0)ions trapped in a hyperbolic Paul trap are firstly observed with the method of time-separated oscillatory fields.The full width at half maximum of central Ramsey fringes is about 25 mHz and the corresponding quality factor Q of the line is greater than 10^(12) for the trapped ^(199)Hg^(+)microwave frequency standard.The hyperfine transition frequency shifted by magnetic field is also measured by the high-resolution Ramsey fringes.The final result isΔνhfs=40507347997.3(0.5)Hz,which is corrected to zero magnetic field.展开更多
The effect of double frequency oftrap fieldφ=U-V1 cosΩt-V2 cos 2Ωt in a Paul trap can be described exactly by using a function series expansion to solve the corresponding Mathieu equation.The stability regions of a...The effect of double frequency oftrap fieldφ=U-V1 cosΩt-V2 cos 2Ωt in a Paul trap can be described exactly by using a function series expansion to solve the corresponding Mathieu equation.The stability regions of a trapped ion are plotted and some meaningful physical results are shown.展开更多
A large cloud of ^(40)Ca^(+) is successfully trapped and manipulated in a linear ion trap.The axial length of the ion cloud is measured under a series of end-cap voltages.We propose a method of measuring the axial sec...A large cloud of ^(40)Ca^(+) is successfully trapped and manipulated in a linear ion trap.The axial length of the ion cloud is measured under a series of end-cap voltages.We propose a method of measuring the axial secular motion temperature of the ion cloud by analyzing its image on an electron-multiplying CCD.The method is based on the Boltzmann equation that the axial density distribution of ions at secular motion temperature T satisfies.The axial secular motion temperature of the ion cloud is also obtained by measuring the Doppler broadened line width.For the same trapping parameters,the axial secular motion temperature by analyzing the image of ion cloud is 840 K and by fitting the experimental resonance line profile is 700 K.展开更多
The charge transfer rate coefficients for reactions of Sc^(3+)with N_(2) and H_(2) have been measured at the mean collision energy of 4.2eV.The rate coefficients are derived from the decay rate of ion signals by using...The charge transfer rate coefficients for reactions of Sc^(3+)with N_(2) and H_(2) have been measured at the mean collision energy of 4.2eV.The rate coefficients are derived from the decay rate of ion signals by using ion storage in a radio-frequency ion trap.The rate coefficients are 8.18(0.18)×10^(-10)cm^(3)·s^(-1) at Tequiv≈1.26×10^(4)K for Sc^(3+) with N_(2) and 1.44(0.39)×10^(-9)cm^(3)·s^(-1) at Tequiv>≈1.67×10^(3) K for Sc^(3+) with H_(2),respectively.Both results are comparable with the Langevin rate coefficients.展开更多
Variations of the hysteresis of the rf detection signals corresponding to the axial motion of an ion cloud in a Paul trap versus the detection voltage,operation parameters and number of ions have been observed.The fea...Variations of the hysteresis of the rf detection signals corresponding to the axial motion of an ion cloud in a Paul trap versus the detection voltage,operation parameters and number of ions have been observed.The features are explained by an extended pseudopotential model with an octupole potential correction and an effective potential from the ion cloud.展开更多
The average kinetic energy of 40 Ca＋ ions is measured by the method of evaporating ions in an rf ion trap. The kinetic energy of the ion 40Ca＋ varies from 0.5eV to 0.2eV with changing buffer gas pressure from 10^-7 ...The average kinetic energy of 40 Ca＋ ions is measured by the method of evaporating ions in an rf ion trap. The kinetic energy of the ion 40Ca＋ varies from 0.5eV to 0.2eV with changing buffer gas pressure from 10^-7 mbar to 10^-5 mbar. The Brownian motion model is also introduced to calculate the average kinetic energy of the trapped ions.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 10904163,11074282.
文摘The Ramsey fringes on the ground-state hyperfine transition of ^(199)Hg^(+)(ΔF=1,ΔmF=0)ions trapped in a hyperbolic Paul trap are firstly observed with the method of time-separated oscillatory fields.The full width at half maximum of central Ramsey fringes is about 25 mHz and the corresponding quality factor Q of the line is greater than 10^(12) for the trapped ^(199)Hg^(+)microwave frequency standard.The hyperfine transition frequency shifted by magnetic field is also measured by the high-resolution Ramsey fringes.The final result isΔνhfs=40507347997.3(0.5)Hz,which is corrected to zero magnetic field.
基金The project supported by National Natural Science Foundation of China under Grant Nos 19904013 and 1904014
文摘The effect of double frequency oftrap fieldφ=U-V1 cosΩt-V2 cos 2Ωt in a Paul trap can be described exactly by using a function series expansion to solve the corresponding Mathieu equation.The stability regions of a trapped ion are plotted and some meaningful physical results are shown.
基金Supported by the National Natural Sciernce Foundation of China under Grant Nos 11074282,10904163.
文摘A large cloud of ^(40)Ca^(+) is successfully trapped and manipulated in a linear ion trap.The axial length of the ion cloud is measured under a series of end-cap voltages.We propose a method of measuring the axial secular motion temperature of the ion cloud by analyzing its image on an electron-multiplying CCD.The method is based on the Boltzmann equation that the axial density distribution of ions at secular motion temperature T satisfies.The axial secular motion temperature of the ion cloud is also obtained by measuring the Doppler broadened line width.For the same trapping parameters,the axial secular motion temperature by analyzing the image of ion cloud is 840 K and by fitting the experimental resonance line profile is 700 K.
基金Supported by the National Natural Science Foundation of China under Grant No.19804015.
文摘The charge transfer rate coefficients for reactions of Sc^(3+)with N_(2) and H_(2) have been measured at the mean collision energy of 4.2eV.The rate coefficients are derived from the decay rate of ion signals by using ion storage in a radio-frequency ion trap.The rate coefficients are 8.18(0.18)×10^(-10)cm^(3)·s^(-1) at Tequiv≈1.26×10^(4)K for Sc^(3+) with N_(2) and 1.44(0.39)×10^(-9)cm^(3)·s^(-1) at Tequiv>≈1.67×10^(3) K for Sc^(3+) with H_(2),respectively.Both results are comparable with the Langevin rate coefficients.
基金Supported by the National Natural Science Foundation of China under Grant No.19674066.
文摘Variations of the hysteresis of the rf detection signals corresponding to the axial motion of an ion cloud in a Paul trap versus the detection voltage,operation parameters and number of ions have been observed.The features are explained by an extended pseudopotential model with an octupole potential correction and an effective potential from the ion cloud.
基金Supported by the National Basic Research Program of China under Grant No 2005CB724500, and the National Natural Science Foundation of China under Grant Nos 60490280 and 10874205.
文摘The average kinetic energy of 40 Ca＋ ions is measured by the method of evaporating ions in an rf ion trap. The kinetic energy of the ion 40Ca＋ varies from 0.5eV to 0.2eV with changing buffer gas pressure from 10^-7 mbar to 10^-5 mbar. The Brownian motion model is also introduced to calculate the average kinetic energy of the trapped ions.
