Lu Fuquan

Experimental Study of Single-Electron Detachment Cross Sections of Cu- in Collision with He

The single-electron detachment cross sections of Cu- in collision with He have been measured in the range of 10-30 keV by a growth rate method. The typical value of the cross section is 7.63×10-16cm2 at an energy of 20 keV. The experimental uncertainty of the results is about ±8%.

Hyperfine structure in the 576 nm line of Pr II by collinear fast-ion-beam laser spectroscopy

Atomic spectra of singly ionized praseodymium have been measured by collinear fast-ion-beam laser spectroscopy. Hyperfine structure in the 576 nm line was resolved and the magnetic dipole and electric quadruple coupling constants were determined.

Optical isotope shifts of Nd II by collinear fast-ion-beam laser spectroscopy

The optical isotope shifts in the transition - of Nd II were measured by using collinear fast-ion-beam laser spectroscopy. The changes in mean-square nuclear charge radii among five even - even neodymium isotopes were deduced from the measured optical isotope shifts: (142,144) 0.269; (144,146) 0.259; (146,148) 0.278; (148,150) 0.403. The configuration admixtures of the previously unclassified level were quantitatively analysed to be , , and with mixing probabilities of 13%, 85%, 2%, respectively.

Single-Electron Detachment for Transition Elements Cr−and Fe− in Collision with He

Single-electron detachment (SED) cross-sections for Cr− and Fe− in collisions with He have been obtained in the energy region of 10–30 keV for the first time. In the present energy range the magnitude of the Cr−+ He SED cross-sections is close to that of Fe−+ He, although the electron affinity of Fe− (0.16 eV) and Cr− (0.668 eV) are different. It is found that the cross-sections for Cr− and Fe− in collisions with He exhibit nearly the same dependence on anions impact velocity.

Single-Electron Detachment Cross Sections for Transition-Element Negative Ions Ti?, Cr?, Cu? in Collision with N2

Single-electron detachment (SED) cross sections for Cr− and Ti− in collision with N2 have been obtained in the energy region of 10–30 keV, for the first time to our knowledge. In the present energy range, the magnitude of the Cr−+N2 and Fe−+N2 SED cross sections is larger than that of Cu−+N2. It is also found that the cross sections for Cr− and Ti− in collisions with N2 exhibit different dependences on anion impact velocity from that of Cu−.

ELECTRON IMPACT IONIZATION CROSS SECTION OF AR+, KR+, IN+ AND GE+

Abstract The single electron impact ionization cross sections of Ar+, Kr+, In+ and Ge+ were measured on the improved electron-ion impact apparatus at Fudan University. The Ar+, Kr+ and In+ experimental results are in good agreement with data from other laboratories. The cross section of Ge+ was measured for the first time. The experimental results indicate that the indirect ionization process gives a larger contribution to the total ionization cross section of In+, as compared to the other three targets. The experimental data were compared with our Distorted-Wave-Born-Exchange-Approximation (DWBEA) calculation, the Lotz formula, and Configuration-Averaged-Distorted-Wave (CADW) calculations.

Lifetime measurement for the (23537)°9/2 level of NdII using the collinear ion beam-laser interaction

The collinear fast ion beam-laser spectroscopy has been used to measure the radiative lifetime of the (23537)°9/2 level of the rare earth ions NdII. The measurement was carried out by the interaction between the 30keV NdII ion beam and tunable collinear dye laser which resonantly excited a metastable level to the (23537)°9/2 level, and by the observation of its time-resolved decay downstream. The lifetime value obtained from a fit program was 27.6±0.9ns. The result may provide a possibility of determining the unknown configuration of the (23537)°9/2 level.

Experimental Study of Single and Double Electron Detachment Cross Sections for Cl− in Collision with He

Single-electron detachment (SED) and double-electron detachment (DED) for chlorine negative ions in collision with helium are investigated in the energy region of 5–30 keV (SED) and 5–19 keV (DED) by growth rate method, respectively. Experimental data from this work are compared with the previous reported data, and a general discussion is given.

Absolute Cross Sections for Single Ionization of Ar+ and Cl+ by Electron Impact

A crossed-beam facility for electron impact ionization of ions was constructed. The absolute cross sections for single ionization of Ar+ and Cl+ ions at electron energies ranging from 30 to 500 eV were measured. The uncertainty is about ±13%.

Production of C60/C70 Ion Beams

With a 30 keV mini-separator at the accelerator laboratory of Fudan University, we have successfully obtained about 1 nA fullerene ion beam. Under the same conditions, we have also observed the fragment ions Cn+ (n=20-40). The C60+ (C70+) beams will be used study collision between fullerene and electrons, atoms and photons.