摘要:

The characteristics of the parametric X-rays from 900 MeV electrons in Ge near theKabsorption edge have been measured. The effect of absorption on radiation yield has been investigated.

ISSN:1042-0150    

DOI:10.1080/10420159308225487

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Basic characteristics of axial channeled electrons at relativistic energies are calculated by using a numerical solution of the Schrödinger equation with a complex potential.

ISSN:1042-0150    

DOI:10.1080/10420159308225488

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A method of calculation of angular distributions of channeled electrons is proposed in the paper. The depth dependence of the angular distribution is investigated. At large penetration depths, the planar channeled particles are seen to spread widely parallel to the atomic planes, while the transverse motion is more confined.

ISSN:1042-0150    

DOI:10.1080/10420159308225489

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Distributions of axially channeled electrons are calculated at large depths as a function of angular momentum and transverse energy. Due to the influence of multiple scattering the electron distributions become independent of the angular momentum at a depth, where the statistical equilibrium is reached. Furthermore, the flux-peaking effect for negative particles is discussed.

ISSN:1042-0150    

DOI:10.1080/10420159308225490

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The penetration of channeled electrons through an area distorted by an edge or screw dislocation is considered. It is shown that this process may be described in the approximation of a sharp shift of atomic rows and planes, which leads to dechanneling about 30% of particles passing through the distorted area. The maximum length of dechannelling in a dislocated crystal and the threshold electron energy, above which the dechannelling length decreases with increase in the energy, was established. Approximate estimates of these values for silicon and tungsten were also received.

ISSN:1042-0150    

DOI:10.1080/10420159308225491

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The finite motion of axial channeling electrons with energy from few MeV up to tens of MeV have been simulated in a computer. For the quasiregular type of motion, electron trajectories with closely lying initial parameters diverge in the phase space. The stochasticity of the transverse energy distribution caused by this divergence, when the string potential is disturbed, leads to difficulties in the dynamical prediction of the system behaviour. For predicting the frequencies in the peak region of radiation spectrum it is sufficient to consider only electrons with quasiresonance trajectories. The radiation calculations are compared with experimental results.

ISSN:1042-0150    

DOI:10.1080/10420159308225492

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Radiation damage produced by channeled heavy ions and relativistic electrons has been considered in terms of Lindhard's basic concepts. Computer simulations as well as analytical estimates agree with the experimental data.

ISSN:1042-0150    

DOI:10.1080/10420159308225493

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Fermilab experimental data on dechanneling length measurements in a bent crystal are well described by a simple model. The dechanneling length is found to be directly proportional to the potential well depth in a bent crystal. The same model could explain the temperature dependence. Optimum curvature and efficiency limit in this model are found as functions of the deflection angle.

ISSN:1042-0150    

DOI:10.1080/10420159308225494

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A capture of quasichanneled particles into planar channels in a nonuniformly bent crystal due to an effective interplanar potential variation for dR/dz > 0 is discussed.

ISSN:1042-0150    

DOI:10.1080/10420159308225495

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Depth distributions of implanted Mg+- and Ca+-ions and the corresponding radiation damage were studied for different channeling orientations of silicon crystals. The shape of the implantation profiles is discussed by using simple models for dechanneling and energy loss processes. A correlation between dechanneling, damage production and depth distributions of the channeled ions could be observed. This correlation is seen by the maxima shifts in damage and implanted ion distributions between channel and random incidence.

ISSN:1042-0150    

DOI:10.1080/10420159308225496

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor