scholarly journals Determination of Inelastic Mean Free Path of High Energy Electrons from Shape Analysis of K-Auger and K-conversion Spectra Emitted from Thin Films

2002 ◽  
Vol 9 (3) ◽  
pp. 281-284
Author(s):  
L. Kövér ◽  
S. Tougaard ◽  
J. Tóth ◽  
D. Varga ◽  
O. Dragoun ◽  
...  
Keyword(s):  
Thin Films ◽  
Free Path ◽  
Shape Analysis ◽  
Mean Free Path ◽  
High Energy ◽  
High Energy Electrons ◽  
Inelastic Mean Free Path

Determination of Mean Free Path for Inelastic Scattering in Poly(2-Vinyl Pyridine) by Low-Loss Spectrum Imaging

2000 ◽  
Vol 6 (S2) ◽  
pp. 224-225
Author(s):  
A. Aitouchen ◽  
T. Chou ◽  
M. Libera ◽  
M. Misra
Keyword(s):  
Free Path ◽  
Free Fall ◽  
Mean Free Path ◽  
Specimen Thickness ◽  
Thickness Determination ◽  
Vinyl Pyridine ◽  
Integrated Intensity ◽  
Inelastic Mean Free Path ◽  
Electron Energy Loss

The common experimental method to determine the total inelastic mean free path i by electron energy-loss spectroscopy (EELS) is by the relation : t/λi= ln(It/IO) [1] where t is the specimen thickness, It, is the total integrated intensity, and Io is the intensity of the zero-loss peak. The accuracy of this measurement depends on the thickness determination. Model geometries like cubes, wedges, and spheres enable accurate thickness determination from transmission images.Spherical polymers with diameters of order 10-200nm can be made from a number of high-Tg polymers by solvent atomization. This research studied atomized spheres of poly(2-vinyl pyridine) [PVP]. A solution of 0.1% PVP in THF was nebulized. After solvent evaporation during free fall within the chamber atmosphere, solid spherical polymer particles with a range of diameters were collected on holey-carbon TEM grids at the bottom of the atomization chamber.

scholarly journals Determination of Inelastic Mean Free Path of Electrons in Noble Metals

1992 ◽  
Vol 81 (2) ◽  
pp. 193-199 ◽  
Author(s):  
W. Doliński ◽  
S. Mróz ◽  
J. Palczyński ◽  
B. Gruzza ◽  
P. Bondot ◽  
...  
Keyword(s):  
Free Path ◽  
Noble Metals ◽  
Mean Free Path ◽  
Inelastic Mean Free Path

Experimental determination of the inelastic mean free path of electrons in GaP and InAs

2000 ◽  
Vol 30 (1) ◽  
pp. 195-198 ◽  
Author(s):  
G. Gergely ◽  
M. Menyhard ◽  
S. Gurban ◽  
Zs. Benedek ◽  
Cs. Daroczi ◽  
...  
Keyword(s):  
Experimental Determination ◽  
Free Path ◽  
Mean Free Path ◽  
Inelastic Mean Free Path

scholarly journals The Influence of Photoelectron Escape in Radiation Damage Simulations of Protein Micro-Crystallography

Crystals ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 267 ◽  
Author(s):  
Hugh Marman ◽  
Connie Darmanin ◽  
Brian Abbey
Keyword(s):  
Radiation Damage ◽  
Global Radiation ◽  
Protein Structures ◽  
Mean Free Path ◽  
High Energy ◽  
Spatially Resolved ◽  
Inelastic Mean Free Path ◽  
The Impact ◽  
Intensity Loss

Radiation damage represents a fundamental limit in the determination of protein structures via macromolecular crystallography (MX) at third-generation synchrotron sources. Over the past decade, improvements in both source and detector technology have led to MX experiments being performed with smaller and smaller crystals (on the order of a few microns), often using microfocus beams. Under these conditions, photoelectrons (PEs), the primary agents of radiation-damage in MX, may escape the diffraction volume prior to depositing all of their energy. The impact of PE escape is more significant at higher beam energies (>20 keV) as the electron inelastic mean free path (IMFP) is longer, allowing the electrons to deposit their energy over a larger area, extending further from their point of origin. Software such as RADDOSE-3D has been used extensively to predict the dose (energy absorbed per unit mass) that a crystal will absorb under a given set of experimental parameters and is an important component in planning a successful MX experiment. At the time this study was undertaken, dose predictions made using RADDOSE-3D were spatially-resolved, but did not yet account for the propagation of PEs through the diffraction volume. Hence, in the case of microfocus crystallography, it is anticipated that deviations may occur between the predicted and actual dose absorbed due to the influence of PEs. To explore this effect, we conducted a series of simulations of the dose absorbed by micron-sized crystals during microfocus MX experiments. Our simulations spanned beam and crystal sizes ranging from 1μm to 5μm for beam energies between 9 keV and 30 keV. Our simulations were spatially and temporarily resolved and accounted for the escape of PEs from the diffraction volume. The spatially-resolved dose maps produced by these simulations were used to predict the rate of intensity loss in a Bragg spot, a key metric for tracking global radiation damage. Our results were compared to predictions obtained using a recent version of RADDOSE-3D that did not account for PE escape; the predicted crystal lifetimes are shown to differ significantly for the smallest crystals and for high-energy beams, when PE escape is included in the simulations.

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