Angular distributions and differential sputtering yields of binary compounds as a function of angle of incidence

The angular dependence of the scattered dose produced by 0.66-Mev γ's incident on concrete, iron, and lead was measured for angles of incidence of 0°, 30°, and 60°. The angular distributions from these materials were dependent both on the angle of incidence and on the angle of scatter to a detector and could not be related to each other by simple multiplicative factors. As the angle of incidence increased, the scattering in the forward directions became increasingly anisotropic for each material. For iron exposed at normal incidence the effect of the scatterer thickness on the angular distribution of the scattered dose was measured also.A Monte Carlo program was used to study the distribution of distances between the point of incidence and the point at which a backscattered γ emerged and indicated that scatter from the "shadow" zone could be significant in some shielding studies. The program was used also to study the distribution of depths of the point at which a backscattered γ had its last scattering interaction.

Download Full-text

Scattering of 4 keV Ne+, Na+ and F+ ions from a NaCl (1 0 0) surface under a small angle of incidence. Angular distributions and charge fractions

Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms ◽

10.1016/s0168-583x(99)01041-1 ◽

2000 ◽

Vol 164-165 ◽

pp. 575-582 ◽

Cited By ~ 3

Author(s):

M Richard-Viard ◽

C Bénazeth ◽

P Benoit-Cattin ◽

P Cafarelli ◽

S Abidi ◽

...

Keyword(s):

Small Angle ◽

Angular Distributions ◽

Angle Of Incidence ◽

Charge Fractions

Download Full-text

Sputtering yields and angular distributions of the eroded atoms for deuterium irradiation of stainless steel 304 LN at temperatures between 300 and 1200 K

Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms ◽

10.1016/0168-583x(89)90006-2 ◽

1989 ◽

Vol 42 (1) ◽

pp. 29-37 ◽

Cited By ~ 7

Author(s):

Wang Wen Min ◽

J. Roth ◽

R. Behrisch

Keyword(s):

Stainless Steel ◽

Angular Distributions ◽

Stainless Steel 304 ◽

Sputtering Yields

Download Full-text

Molecular Dynamics Simulations of Growth and Low-Energy Ion Polishing of Thin Molybdenum Films for EUV Multilayer Mirrors

MRS Proceedings ◽

10.1557/proc-585-305 ◽

1999 ◽

Vol 585 ◽

Author(s):

Peter Klaver ◽

Wim Goedheer ◽

Fred Bijkerk ◽

Barend J. Thijsse

Keyword(s):

Molecular Dynamics ◽

Extreme Ultraviolet ◽

Amorphous Film ◽

Angle Of Incidence ◽

Multilayer Mirror ◽

Ion Energies ◽

Report Data ◽

Dynamics Simulations ◽

Short Time ◽

Sputtering Yields

AbstractWe report on the simulation of the growth and subsequent krypton ion polishing of thin molybdenum films, required for extreme ultraviolet multilayer mirror fabrication. We have used a comprehensive Molecular Dynamics (MD) code, principally enabling a simulation of the deposition, ion bombardment and annealing processes. Ion energies used are in the sub-keV range, and the ion angle of incidence is varied between 30 and 60 degrees off-normal.The effects of ion polishing on the surface roughness are discussed, as well as the increase in (surface) atom mobility. We also report data on sputtering yields, ion penetration depths, trapping, energy transfer and krypton implantation and saturation.The results are compared with TRIM results, and the relevance of MD and TRIM simulations for specific purposes is discussed. Also, the effects of short-time, high-temperature annealing of an amorphous film are investigated.

Download Full-text

THE ENERGY AND ANGULAR DISTRIBUTIONS OF LOW-ENERGY He+ SCATTERED FROM Al(111)

Surface Review and Letters ◽

10.1142/s0218625x99000561 ◽

1999 ◽

Vol 06 (05) ◽

pp. 605-611 ◽

Cited By ~ 3

Author(s):

R. BASTASZ ◽

J. A. WHALEY ◽

W. P. ELLIS

Keyword(s):

Multiple Scattering ◽

Oblique Incidence ◽

Nearest Neighbor ◽

Incidence Angle ◽

Single Scattering ◽

Angular Distributions ◽

Angle Of Incidence ◽

Glancing Angle ◽

Energy And Angular Distributions ◽

Critical Incidence

Measurements of 500 eV 4 He + scattered from Al(111) surfaces provide detailed information about the scattering process and surface crystallography. We report various observations concerning collision inelasticity, multiple scattering, and shadow-cone focusing effects. A large inelastic energy loss of the scattered He + is observed, which causes multiple-scattering events at oblique incidence angles to have energies below the elastic single-scattering energy. Inelastic He + scattering from clean, ordered Al(111) shows interesting intensity variations as a function of azimuthal orientation and incidence angle. At a critical incidence angle, where the top edge of a shadow cone intersects a nearest-neighbor Al surface atom, the scattered ion intensity exhibits 60° azimuthal periodicity. At a more glancing angle of incidence, a double-peaked structure appears. The scattered He + intensity varies as a function of incidence angle, as expected from classical shadow cone calculations.

Download Full-text

Electron Channeling Patterns

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100077700 ◽

1977 ◽

Vol 35 ◽

pp. 12-13

Author(s):

David C. Joy

Keyword(s):

Electron Diffraction ◽

Incidence Angle ◽

Photographic Plate ◽

Diffraction Effect ◽

Angle Of Incidence ◽

Bulk Single Crystal ◽

Time Resolved ◽

Electron Channeling ◽

Spatially Resolved ◽

Large Bulk

Electron channeling patterns (ECP) were first found by Coates (1967) while observing a large bulk, single crystal of silicon in a scanning electron microscope. The geometric pattern visible was shown to be produced as a result of the changes in the angle of incidence, between the beam and the specimen surface normal, which occur when the sample is examined at low magnification (Booker, Shaw, Whelan and Hirsch 1967).A conventional electron diffraction pattern consists of an angularly resolved intensity distribution in space which may be directly viewed on a fluorescent screen or recorded on a photographic plate. An ECP, on the other hand, is produced as the result of changes in the signal collected by a suitable electron detector as the incidence angle is varied. If an integrating detector is used, or if the beam traverses the surface at a fixed angle, then no channeling contrast will be observed. The ECP is thus a time resolved electron diffraction effect. It can therefore be related to spatially resolved diffraction phenomena by an application of the concepts of reciprocity (Cowley 1969).

Download Full-text