摘要:

We calculate the emergence angle dependent energy loss of high energy ions, using the transport theory developed by Jakaset al.and by Yamashita. We developed the theory of impact parameter dependent stopping power taking into account the Barkas effect. Our calculation shows relatively good agreement with the recent experiments by Ishiwariet al.

ISSN:1042-0150    

DOI:10.1080/10420159108220614

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

ISSN:1042-0150    

DOI:10.1080/10420159108220615

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The stopping power and range for Xe ions in high temperature matter (partially ionized plasmas) have been calculated using the dielectric response function method. Calculations have been made for a target matter Al (Z= 13) over a wide range of temperatures and densities considering a finite temperature model. The stopping powers obtained have smaller values in comparison with those of a zero temperature model. The stopping power strongly depends on the density and temperature of the target material, and the projectile ion energy.

ISSN:1042-0150    

DOI:10.1080/10420159108220616

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

A theoretical treatment of inelastic scattering of low energy particles from surfaces is developed which treats the regime of multiple quantum phonon exchange. Good agreement is obtained with recently measured multiphonon backgrounds in the scattering of He by alkali halide and metal surfaces over a large range of surface temperatures and incident conditions. The results show that the multiphonon scattered intensity can give important information on the particle-surface interaction potential.

ISSN:1042-0150    

DOI:10.1080/10420159108220617

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

This paper reports the results of Monte Carlo transport calculations for electrons in strong electric fields in silicon dioxide based on new choices for the deformation potential in acoustic phonon scatter and for the ionization threshold. Impact ionization is described on the basis of cross sections derived from many body dielectric theory coupled to a model insulator. The electron-acoustic and electron-elastic scattering rates are matched at 8 eV in order to provide appropriate limitation on the electron-phonon scattering. The sensitivity of secondary electron production to these parameters is described. Also described is the important role of bulk trapped negative charge in affecting secondary electron production by changing the local field value. The results show that suitable choices for these parameters lead to appropriate levels of impact ionization and vacuum emission spectra.

ISSN:1042-0150    

DOI:10.1080/10420159108220618

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

An accurate knowledge of electron stopping power is important for calculations and simulations of electron beam interactions with solids especially in the low energy region (< 10 keV). This paper describes a simplified and rapid experimental procedure using based on electron energy loss spectroscopy which permits accurate stopping power determinations to be made from any material which can be observed in a transmission electron microscope. It is demonstrated that the stopping power and oscillator strength data so generated is in good agreement with other measurements and theoretical predictions. The technique is now being applied to a wide variety of materials of semiconductor interest.

ISSN:1042-0150    

DOI:10.1080/10420159108220619

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

ISSN:1042-0150    

DOI:10.1080/10420159108220620

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Theoretical calculations of positronium emission fraction are compared with experiments. The results show that positronium emission fraction is quite sensitive to screening effects. Thus, positronium formation will be a very good example for testing dynamical screening effects. An experimental angle-resolved energy spectrum of positronium is required for more detailed discussion.

ISSN:1042-0150    

DOI:10.1080/10420159108220621

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

ISSN:1042-0150    

DOI:10.1080/10420159108220622

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The characteristics of stored ions in a Kingdon trap have been investigated. The charge distribution of stored ions was measured by a time of flight (TOF) mass spectrometer. Storage of Arq+(q= 1, 2, 3, 4) produced by electron beam irradiation has been confirmed. The dependences of Ar ion yields on the trapping potential and storage time have been systematically studied.

ISSN:1042-0150    

DOI:10.1080/10420159108220623

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor