Zhang Xue-Mei

Single-Electron Detachment for Ti−, Fe−, Co−, Ni− and Cu− in Collision with Ar

By using the micro-channel plate position sensitive detector with the delay-line anode we measure the single electron detachment cross sections for some transition elements in collision with Ar in the energy region 10–30 keV. These single electron detachment cross sections perform as velocity and electron affinity dependences. The experiments are carried out using the growth rate method.

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%.

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−.

KLn Dielectronic Recombination Process of B- Through He-like Cu Ions

The KLn dielectronic recombination processes of trapped highly charged B-like through He-like Cu ions are studied theoretically, and the theoretical results are used to analyse our previous experimental data at Heidelberg electron beam ion trap (EBIT). The theoretical resonant positions agree with the experimental resonant positions to a precision of 0.4%, in comparison with the resonant positions of those highest peaks between theory and experiment. The experimental spectra are then fitted using a formula with the theoretical resonant energies and strengths, the result shows good overall agreement between theory and experiment over a wide electron energy range. The distribution of highly charged states is obtained from the fitting parameters.

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.

Cross Sections of Electron Detachment for Si− and Ge− in Collision with Ar

Single electron detachment cross section for 10–40 keV Si− and Ge− in collisions with Ar are measured and compared with other available experimental results. In our experimental energy region, the trend of cross sections is almost constant. The cross sections of Ge larger than Si can be understood by including electron affinity and size of negative ions.

Experimental Study of Single- and Double-Electron Detachment for Negative Carbon Ions Incident on Helium

Using the growth rate method, we obtain the single-electron detachment (SED) cross-sections for 5–30 keV C−+He, and double-electron detachment (DED) cross-sections for 5–15 keV C−−+He. The SED cross-sections first increase with the increasing incident ion energy, and then decrease with further increase of the energy. The DED cross-sections increase with the increasing incident energy in the 5–15 keV region.