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P. B. Kats

Publications and source records attributed to P. B. Kats.

4 recordsLinked to original sources

Some Approaches to the Energy-Loss Straggling Calculation

Some exact and approximate methods commonly used to calculate corrections to the Bethe stopping formula are modified and adapted by the authors to the calculation of the energy loss straggling. An intercomparison is carried out for results of approaches developed in the present work. An excellent agreement obtained between the results for ELS, calculated with an exact method previously proposed by one of the authors and the results of the Lindhard-Sorensen method for moderate relativistic energies. It is shown that some modified by authors approximate methods for the ELS calculating have the higher accuracy than the conventional approximate method of Lijian-Qing-Zhengming. So, in all the cases considered, the accuracy of the twice modified LQZ method in the ELS calculations is higher than the accuracy of the usual LQZ method. A thrice modified LQZ method was also suggested in this work. A number of shortened LQZ methods for the ELS calculating have been proposed and developed too.

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Comparison of the Lindhard-Sorensen and Mott-Bloch corrections to the Bethe stopping formula at moderately relativistic energies

The results of numerical calculating the total Mott-Bloch correction to the Bethe stopping formula and the Lindhard-Sorensen correction in the point nucleus approximation, as well as the Mott correction and the difference between the Lindhard-Sorensen and Bloch corrections, which were obtained by some rigorous and approximate methods, are compared for the ranges of a gamma factor of approximately from 1 to 10 and the ion nuclear charge number Z from 6 to 114. It is shown that the accurate calculation of the Mott-Bloch corrections based on the Mott exact cross section using a method previously proposed by one of the authors gives excellent agreement between its values and the values of the Lindhard-Sorensen corrections in the gamma and Z ranges under consideration. In addition, it is demonstrated that the results of stopping power calculations obtained by the two above-mentioned rigorous methods coincide with each other up to the seventh significant digit and provide the best agreement with experimental data in contrast with the results of some approximate methods, such as the methods of Ahlen, Jackson-McCarthy, etc.

nucl-th

Regularization of the Coulomb scattering problem

Exact solutions of the Schrödinger equation for the Coulomb potential are used in the scope of both stationary and time-dependent scattering theories in order to find the parameters which define regularization of the Rutherford cross-section when the scattering angle tends to zero but the distance r from the center remains fixed. Angular distribution of the particles scattered in the Coulomb field is investigated on the rather large but finite distance r from the center. It is shown that the standard asymptotic representation of the wave functions is not available in the case when small scattering angles are considered. Unitary property of the scattering matrix is analyzed and the "optical" theorem for this case is discussed. The total and transport cross-sections for scattering of the particle by the Coulomb center proved to be finite values and are calculated in the analytical form. It is shown that the considered effects can be essential for the observed characteristics of the transport processes in semiconductors which are defined by the electron and hole scattering in the fields of the charged impurity centers.

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