Charged‐particle stopping in crystals

Khodyrev, V.A.; Sirotinin, E.I.

doi:10.1002/pssb.2221160228

Cited by 21 publications

(3 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…where Ei(z) is the exponential-integral function. The same result, though in a different form, was obtained in [17], where the perturbation approach was applied from the outset. The corresponding classical phenomenon, the stopping in a uniform electron gas, can be described using the quasiclassical solution of equation ( 30),…”

Section: Energy Loss To a Free Electronsupporting

confidence: 52%

On the origin of the Bloch correction in stopping

Khodyrev¹

2000

J. Phys. B: At. Mol. Opt. Phys.

View full text Add to dashboard Cite

Abstract. The energy loss in the collision of a moving charged projectile with a free electron is described in a rigorous approach. The collision is treated as stationary scattering of an electron in the projectile Coulomb field. In the laboratory frame, the picture can be represented as a spatial distribution of energy losses to the electron. It has been shown that the local rate of the energy gain can be presented as a product of the induced electron current and the projectile electric field. The analytical results and numerical calculations reveal a principal disagreement with the generally recognized condition for the classical description, η = Z 1 e 2 /hv 1 (Z 1 e and v are, respectively, the charge and velocity of the projectile): for any value of η, the quantum effects appear to be significant in the close vicinity of the projectile trajectory (small impact parameters) restricted by the distance ∼λ =h/mv. Essentially, the problem has been cleared in the qualitative analysis of collisions with electron wavepackets. The main results of the Bloch theory are reproduced in a simpler way. The clearer basis permits us to eliminate the ambiguity in the interpretation of the origin of the Bloch correction, which reflects in fact the evolution of the classical features in the quantum mechanical picture.

show abstract

Section: Energy Loss To a Free Electronsupporting

confidence: 52%

On the origin of the Bloch correction in stopping

Khodyrev¹

2000

J. Phys. B: At. Mol. Opt. Phys.

View full text Add to dashboard Cite

show abstract

“…With ek; o given by ( 8), this results in conversion of expression (6) for Gr; v; s into that derived in Ref. [9]. In both cases, the free electron model is treated in the ¢rst-order perturbation approach.…”

Section: The Dielectric Approachmentioning

confidence: 99%

“…The latter presents the dispersion curve o p k for collective, plasmon, excitations of the electron gas. In the integration over u in (9) for a ¢xed z, the residue at a pole on the plasmon curve can be found using the Bethe sum rule [10] for the retarded dielectric function of a free electron gas. Using the variables u and z, the sum rule is written as…”

Section: The Dielectric Approachmentioning

confidence: 99%

The Local Plasma Frequency Approach in Description of the Impact-Parameter Dependence of Energy Loss

Khodyrev

2001

Phys. Scr.

View full text Add to dashboard Cite

The LPF approach of Lindhard and Scharff is generalized to describe on the same basis the impact parameter dependence of energy loss in ion–atom collision. To make this feasible the energy loss is represented as an integral of the local energy deposition over the atomic shell volume. The local energy loss is determined by the induced electron current and the intensity of the projectile field at a given point. The LPF approach consists in an approximate description of the induced current using the corresponding expression for a uniform electron gas. With an appropriate description of the electron gas response, the atomic shell polarization and the state of electron motion are considered. The developed approach provides a possibility to test the accuracy of the customary approximation where the energy loss is expressed through the electron density on the ion trajectory, the local density approximation. A comparison with the available experimental results displays the adequateness of the developed approach if, additionally, the higher-order corrections over the projectile charge are taken into account.

show abstract

The role of single collisions in the process of scattering and stopping of 200 to 400 keV protons in thin gold foils

Bednyakov

Iferov

Kadmenskii

et al. 1987

Physica Status Solidi (b)

View full text Add to dashboard Cite

The trajectories of 200 to 400 keV protons in 5 to 18 nm thick gold foils are simulated by means of Monte-Carlo calculations. The impact-parameter distributions of ion-atomic collisions a t different emission angles are obtained. The impact-parameter distributions of the mean energy transfered to the atom a t given emission angles are calculated. The angular dependence of the mean energy loss is also calculated. By fitting the latter with experiment the impact-parameter dependence of the energy transfer in a single collision is obtained. I n connection with many new applications of ion-beam methods in science and technology it has become necessary to describe the passage of light ions through matter at greater length. Specifically, this concerns the contribution provided by a single collision in the multiple scattering on target atoms to the total deviation from the initial direction and to the total energy losses of particles emitted from the target a t a given angle 8. The contribution of collisions with different impact parameters p t o the resultant deviation 8 and the p-dependence of the energy transfer q in a single collision have not yet been studied well. The theoretical estimates of the dependence q(p) [ l , 21 are contradictory and direct measurements are not available.In [3 to 71 the dependence of the energy losses AE on the emission angle 8 a t different initial conditions was experimentally studied and some tentative conclusions about the dependence q ( p ) were made. In the present paper we attempt to analyze our previous results [4] by means of a computer simulation of particle trajectories in the target. The purpose of the calculations was to determine the contribution of the collisions with differing impact parameters p to the total deviation of a particle (at an angle 8) and to elucidate the possibility of extracting the q ( p ) data from the experimental results obtained a t finite target thickness. The calculations were made for the passage of protons with energy E = 200 and 400 keV through the 5, 9, and 1 8 n m thick gold foils. The impact-parameter ( p ) l) 119899 Moscow, USSR.

show abstract

Charged‐particle stopping in crystals

Cited by 21 publications

References 16 publications

On the origin of the Bloch correction in stopping

On the origin of the Bloch correction in stopping

The Local Plasma Frequency Approach in Description of the Impact-Parameter Dependence of Energy Loss

The role of single collisions in the process of scattering and stopping of 200 to 400 keV protons in thin gold foils

Contact Info

Product

Resources

About