Calculation of the exposure buildup factors for x-ray photons with continuous energy spectrum using Monte Carlo code

AbstractA previously developed Monte Carlo code has been extended to the X-ray microanalysis in a (scanning) transmission electron microscope of plan sections, consisting of bilayers and triple layers. To test the validity of this method for quantification purposes, a commercially available NiOx (x ∼ 1) thin film, deposited on a carbon layer, has been chosen. The composition and thickness of the NiO film and the thickness of the C support layer are obtained by fitting to the three X-ray intensity ratios I(NiK)/I(OK), I(NiK)/I(CK), and I(OK)/I(CK). Moreover, it has been investigated to what extent the resulting film composition is affected by the presence of a contaminating carbon film at the sample surface. To this end, the sample has been analyzed both in the (recommended) “grid downward” geometry and in the upside/down (“grid upward”) situation. It is found that a carbon contaminating film of few tens of nanometers must be assumed in both cases, in addition to the C support film. Consequently, assuming the proper C/NiOx/C stack in the simulations, the Monte Carlo method yields the correct oxygen concentration and thickness of the NiOx film.

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Application of continuous-energy Monte Carlo code as a cross-section generator of BWR core calculations

Annals of Nuclear Energy ◽

10.1016/j.anucene.2005.01.002 ◽

2005 ◽

Vol 32 (8) ◽

pp. 857-875 ◽

Cited By ~ 16

Author(s):

Masayuki Tohjoh ◽

Masato Watanabe ◽

Akio Yamamoto

Keyword(s):

Monte Carlo ◽

Cross Section ◽

Monte Carlo Code ◽

Continuous Energy

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Characterization of laser-driven electron and photon beams using the Monte Carlo code FLUKA

Laser and Particle Beams ◽

10.1017/s0263034614000044 ◽

2014 ◽

Vol 32 (2) ◽

pp. 233-241 ◽

Cited By ~ 9

Author(s):

F. Fiorini ◽

D. Neely ◽

R.J. Clarke ◽

S. Green

Keyword(s):

Monte Carlo ◽

Electron Temperature ◽

Spectral Characteristics ◽

Simulation Method ◽

Target Thickness ◽

Monte Carlo Code ◽

X Rays ◽

Photon Beams ◽

X Ray ◽

Plasma Effects

AbstractWe present a new simulation method to predict the maximum possible yield of X-rays produced by electron beams accelerated by petawatt lasers irradiating thick solid targets. The novelty of the method lies in the simulation of the electron refiluxing inside the target implemented with the Monte Carlo code Fluka. The mechanism uses initial theoretical electron spectra, cold targets and refiluxing electrons forced to re-enter the target iteratively. Collective beam plasma effects are not implemented in the simulation. Considering the maximum X-ray yield obtained for a given target thickness and material, the relationship between the irradiated target mass thickness and the initial electron temperature is determined, as well as the effect of the refiluxing on X-ray yield. The presented study helps to understand which electron temperature should be produced in order to generate a particular X-ray beam. Several applications, including medical and security imaging, could benefit from laser generated X-ray beams, so an understanding of the material and the thickness maximizing the yields or producing particular spectral characteristics is necessary. On the other more immediate hand, if this study is experimentally reproduced at the beginning of an experiment in which there is an interest in laser-driven electron and/or photon beams, it can be used to check that the electron temperature is as expected according to the laser parameters.

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