ELECTRON-CAPTURE FROM ONE-ELECTRON AND 2-ELECTRON ATOMS BY FAST POSITRONS IN DENSE-PLASMAS

Electron capture processes by positrons from one- and two-electron ato ms in dense plasmas are investigated in accordance with the classical Bohr-Lindhard model using the modified hyperbolic-orbit trajectory met hod. The interaction potential in dense plasmas has been approximated by the Debye-Huckel model. The modified hyperbolic-orbit trajectory fo r the positron path is obtained by the combination of the hyperbolic-o rbit and straight-line trajectories with the modified impact parameter . The maximum value of the electron capture probability per electron f or two-electron (He-like) atoms is smaller than that for one-electron (H-like) atoms. The maximum position of the electron capture probabili ty is slightly shifted to the target nucleus with an increase of the t arget charge. The plasma-screening effect on the electron capture prob ability for He-like atoms is more effective than that for H-like atoms . However, the capture probabilities obtained by the straight-line tra jectory for H-like and He-like atoms are identical. (C) 1997 American Institute of Physics.