Z. Kaliman and K. Pisk and B. A. Logan, Nuclear Excitation In Positron--K-Electron Annihilation, Phys. Rev. C 35, (1987), 1661--1665

ABSTRACT   We have calculated the cross section for nuclear excitation during positron--K-electron annihilation. The calculations allow for the effect of the nuclear Coulomb field and for relativistic effects. the results are compared to earlier predictions which were derived using the Born approximation, and to renormalized Born approximation predictions. Our calculated cross sections are well below the available experimental values.

Z. Kaliman and K. Pisk and B. A. Logan, Calculation Of Nuclear Excitation In An Electron Transition, Nuclear Physics A 04, (1989), 103-108

ABSTRACT   We have made a theoretical investigation of nuclear excitation during an electron transition (NEET). Our approach allows us to express the NEET probabilities in terms of the excited nuclear level width, the energy difference between the nuclear and electron transition, the Coulomb interaction between the initial electron states, and the electron level width. A comparison is made with the available experimental results.

Z. Kaliman and T. Surić and K. Pisk and R. H. Pratt, Triply Differential Cross Section For Compton Scattering, Phys. Rev. A 57, (1998), 2683--2691

ABSTRACT   The triply differential cross section for Compton scattering from atomic electrons is obtained numerically in a full relativistic second-order S-matrix calculation based on the independent particle approximation. We compare our results with the results of more approximate approaches. Special attention is paid to the validity of the impulse approximation (IA)!, which has often been used for calculating the doubly differential cross section even when the photon momentum transfer K is similar to the average momentum p_av of the bound electron, which is ionized (and IA is found to be fairly accurate even in such circumstances). We here show that, on the contrary, IA calculations of the (less averaged) triply differential cross section are quite inaccurate for |K| ~ p_av , even near the peak in the triply differential cross section (where the free kinematics for scattering from an initial free electron at rest are satisfied and where IA should work the best). We conclude that electron momentum distribution determination through the Compton profile, using the doubly differential cross section, is more accurate at lower energies than direct determination through the measurement of the triply differential cross section at the same energy. In addition, viewing the total cross section for double ionization in Compton scattering as another observable less averaged than the doubly differential cross section in single ionization, we estimate that IA predictions of the total cross section for double ionization in Compton scattering from Helium are adequate above about 50 keV.

Z. Kaliman and T. Surić and K. Pisk and R. H. Pratt, Compton Scattering In Determination Of Electron Momentum Density, Fizika A 9, (2000), 1-8

ABSTRACT   We present new insights regarding the validity of the impulse approximation (IA) in determining electron momentum density (EMD) from Compton scattering. These insights are obtained utilizing the code we have recently developed for the full calculation of the triple diferential cross-section (TDCS) for Compton scattering. We find that, due to the averaging, at lower energies IA is more accurate for the double diferential cross-section (DDCS) than for TDCS. We conclude that at such energies an EMD determination from the DDCS is more accurate than its direct determination through the measurement of the TDCS at the same energy. We also discuss the validity of IA for calculations of other less averaged Compton observables.

Z. Kaliman and N. Orlić, Nuclear Excitation By Positron Annihilation With Bound Electrons In Screened Atomic Potential, Radiation Physics And Chemistry 61, (2001), 355-357

ABSTRACT   We have calculated the total cross section for the process of nuclear excitation in positron-bound electron annihilation.The calculations presented in this work use a spherically symmetric screened atomic potential. Comparisons with more approximate treatments of the process are made.

N. Orlić and Z. Kaliman, Mechanism For Nuclear Excitation During Positron Annihilation Using Coulomb Wave Functions, Radiation Physics And Chemistry 61, (2001), 387-389

ABSTRACT   We have calculated cross sections for the process of nuclear excitation during positron annihilation on any bound electron.We used Coulomb wave functions for the electron and positron.

B. Siegmann and U. Werner and R. Mann and Z. Kaliman and N.M. Kabachnik and H.O. Lutz, Orientation dependence of multiple ionization of diatomic molecules in collisions with fast highly-charged ions, Phys. Rev A 65, (2002), 010704

ABSTRACT   We report an observation of the strong dependence of the multiple (6,q<10) ionization cross section on the alignment of the molecular axis in collisions of highly charged Xe ions with N₂ molecules at an impact energy of 5.9 MeV/amu. Theoretical calculations based on the statistical-energy-deposition model well describe the experimental data.

B. Siegmann and U. Werner and Z. Kaliman and Z. Roller-Lutz and N. M. Kabachnik and H. O. Lutz, Multiple ionization of diatomic molecules in collisions with $50 –- 300-keV hydrogen and helium ions, Phys. Rev A 66, (2002), 052701

ABSTRACT   Measurements of relative multiple ionization cross sections have been performed for 50–300-keV  H⁺, D⁺, and He⁺ impact on N₂ , O₂ , CO, and NO molecules. Fragment ions with total charges up to Q = q₁ + q₂ = 5 have been detected in coincidence using a position- and time-sensitive detector. Dependence of the cross section on the molecular orientation with respect to the ion beam is observed for all targets. The experimental data are compared with theoretical calculations based on the statistical energy deposition model.