scholarly journals The Energy Loss Distributions of 1 MeV Electrons in Aluminium Foils

1955 ◽  
Vol 8 (1) ◽  
pp. 98 ◽  
Author(s):  
JA McDonell ◽  
MA Hanson ◽  
PR Wilson
Keyword(s):  
Energy Loss ◽  
Multiple Scattering ◽  
Energy Losses ◽  
Loss Distributions ◽  
Good Agreement

The energy loss distributions for 1 MeV electrons traversing aluminium foils of various thicknesses have been investigated experimentally. Several of the foils were of thicknesses such that the distributions were expected to show considerable effects due to multiple scattering. It was found that the most probable energy losses were in good agreement with those predicted by the calculations of Hebbard and Wilson (1955).

scholarly journals A Method of Predicting the Energy Losses in Vaneless Diffusers of Centrifugal Compressors

1989 ◽  
Author(s):  
Huashu Dou
Keyword(s):  
Experimental Data ◽  
Energy Loss ◽  
Total Energy ◽  
Wall Friction ◽  
Energy Losses ◽  
Flow Conditions ◽  
Centrifugal Compressors ◽  
Flow Losses ◽  
Vaneless Diffusers ◽  
Good Agreement

The flow losses in the veneless diffusers of centrifugal compressors is investigated. It is found that the total energy loss in vaneless diffusers is a function of Bsin2 α0 when inlet flow conditions and radius ratio between inlet and outlet are given. A wall friction coefficient equation is derived and a method of predicting the total energy loss excepting mixing loss is presented. A comparison is made between results obtained from this method and experimental data generated by the author as well as data from the literature. Good agreement is obtained.

scholarly journals The Effect of Multiple Scattering on Electron Energy Loss Distributions

1955 ◽  
Vol 8 (1) ◽  
pp. 90 ◽  
Author(s):  
DF Hebbard ◽  
PR Wilson
Keyword(s):  
Energy Loss ◽  
Multiple Scattering ◽  
Electron Energy ◽  
Appreciable Effect ◽  
Loss Distribution ◽  
Loss Distributions ◽  
Electron Energy Loss

Calculations have been performed to obtain the theoretical energy loss distributions of 1 MeV electrons traversing foils thick enough for multiple scattering to be important. A criterion has been developed and applied to previous experiments to determine the foil thicknesses for which multiple scattering has an appreciable effect on the energy loss distribution.

Background Fitting in the Low-Loss Region of Electron Energy Loss Spectra

1990 ◽  
Vol 48 (2) ◽  
pp. 56-57
Author(s):  
C P Scott ◽  
A J Craven ◽  
C J Gilmore ◽  
A W Bowen
Keyword(s):  
Energy Loss ◽  
Multiple Scattering ◽  
Simple Form ◽  
Single Scattering ◽  
Low Loss ◽  
Characteristic Energy ◽  
Normal Method ◽  
Fitting In ◽  
Electron Energy Loss ◽  
Electron Energy Loss Spectra

The normal method of background subtraction in quantitative EELS analysis involves fitting an expression of the form I=AE-r to an energy window preceding the edge of interest; E is energy loss, A and r are fitting parameters. The calculated fit is then extrapolated under the edge, allowing the required signal to be extracted. In the case where the characteristic energy loss is small (E < 100eV), the background does not approximate to this simple form. One cause of this is multiple scattering. Even if the effects of multiple scattering are removed by deconvolution, it is not clear that the background from the recovered single scattering distribution follows this simple form, and, in any case, deconvolution can introduce artefacts.The above difficulties are particularly severe in the case of Al-Li alloys, where the Li K edge at ~52eV overlaps the Al L2,3 edge at ~72eV, and sharp plasmon peaks occur at intervals of ~15eV in the low loss region. An alternative background fitting technique, based on the work of Zanchi et al, has been tested on spectra taken from pure Al films, with a view to extending the analysis to Al-Li alloys.

THE ENERGY LOSS, THE DETERIORATION DEPTH, AND THE LIGHT OUTPUT FOR HEAVY IONS IN ZnO:Zn

1967 ◽  
Vol 45 (12) ◽  
pp. 4039-4051 ◽  
Author(s):  
L. Hastings ◽  
A. van Wijngaarden
Keyword(s):  
Energy Loss ◽  
Heavy Ions ◽  
Light Output ◽  
Average Energy ◽  
Ion Beams ◽  
Low Energy ◽  
Energy Losses ◽  
Sufficient Energy ◽  
Low Energy Ions ◽  
Total Average

Local regions on the surface of ZnO:Zn phosphor samples were deteriorated by a large number of low-energy ions. In this manner thin films which did not luminesce under ion bombardment were prepared. The phosphor samples were then scanned across energetic ion beams with sufficient energy to traverse the thin phosphor films. By comparing the luminescent response to this ion excitation in the damaged and undamaged portions of the phosphor surface, the total average energy losses of 1H, 4He, 14N, 40Ar, and 84Kr in passing through the films were determined. It was found that the energy losses for the heavier projectiles, when compared with the energy loss of hydrogen, are appreciably smaller than the energy losses predicted by the Lindhard and Scharff theory.The deterioration depth of the phosphor under prolonged bombardment is proportional to the speed of the damaging projectiles.

Energy losses of ions implanted in matter

1996 ◽  
Vol 11 (11) ◽  
pp. 2876-2883 ◽  
Author(s):  
J. H. Liang ◽  
K. Y. Liao
Keyword(s):  
Energy Loss ◽  
Nuclear Energy ◽  
Critical Energy ◽  
Carbon Films ◽  
Electronic Energy ◽  
Energy Losses ◽  
Nuclear Energy Loss ◽  
Light Ions ◽  
First Moment ◽  
First Four Moments

A set of simple and accurate formulae for the first four moments of nuclear and electronic energy losses is proposed. A new variable is introduced to include the finite maximum-impact-parameter effect in the nuclear stopping process, which is assumed to be infinite in most studies. A critical energy at which the electronic energy loss is equal to the nuclear energy loss is also defined. It determines whether the nuclear or the electronic stopping process is the dominant mechanism in terms of incident-ion energy. The critical energy increases for heavy ions implanted in heavy target materials during the first moment of energy loss. The second moment of electronic energy loss is important only for light ions implanted at high ion energies. The third and fourth moments of nuclear energy loss are much larger than those of the electronic energy loss for all ion-target combinations. Theoretical predications of the projected ranges and range stragglings for gold ions implanted in carbon films are close to the experimental data when these proposed four moments of nuclear and electronic energy losses are considered.

Belt-Drive Mechanics: Energy Losses in the Presence of Detachment Waves

2019 ◽  
Author(s):  
Yingdan Wu ◽  
Michael J. Leamy ◽  
Michael Varenberg
Keyword(s):  
Rolling Friction ◽  
Drive System ◽  
Energy Losses ◽  
Belt Drive ◽  
Interface Shear ◽  
Shear Traction ◽  
Friction Moment ◽  
The Difference ◽  
Contact Arc ◽  
Good Agreement

Abstract The dissipative rolling friction moment in a simple belt-drive system is estimated both experimentally and computationally while taking into account the detachment events at the belt-pulley interface. Shear traction is estimated based on measurements of the shear strain along the contact arc. It is shown that the dissipative moment can be approximated by taking the difference between the shear traction and the load carried by the belt. A model is developed for analyzing the contributions of different components to this dissipative moment by considering both the volumetric and surface hysteresis losses. The computed rolling friction moment is found to be in good agreement with that estimated based on the experiments. It is also found that while the shear- and stretching-induced energy losses contribute the most to the dissipation in the belt drive system, the losses associated with the Schallamach waves of detachment make up a considerable portion of the dissipation in the driver case.

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