Radiolysis of supercritical water at 400 °C and liquid-like densities near 0.5 g/cm3 — A Monte Carlo calculation

2010 ◽  
Vol 88 (7) ◽  
pp. 646-653 ◽  
Author(s):  
Jintana Meesungnoen ◽  
David Guzonas ◽  
Jean-Paul Jay-Gerin
Keyword(s):  
Monte Carlo ◽  
Supercritical Water ◽  
Diffusion Coefficients ◽  
Monte Carlo Calculation ◽  
Picosecond Pulse ◽  
Good Accord ◽  
Radiation Induced ◽  
Sum Formula ◽  
Available Information ◽  
And Diffusion

Monte Carlo simulations are used to calculate the primary radical yields [Formula: see text], g(•OH), the sum [[Formula: see text] + g(•OH) + g(H•)], and the ratio g(H•)/[Formula: see text] in the low linear energy transfer (LET) radiolysis of supercritical water (SCW) at 400 °C in the high-density, liquid-like region near ∼0.5 g/cm3. Using all the currently available information on the reactivities and diffusion coefficients of the radiation-induced species under these conditions, and assuming the aqueous medium to be a “continuum”, a good accord is found between our calculations and the available experimental data. In particular, our computed [Formula: see text] yields at 60 ps and 1 ns compare very well with recently reported direct time-dependent [Formula: see text] yield measurements in SCW (D2O) at 400 °C and 0.570 g/cm3 using picosecond pulse radiolysis experiments.

Monte Carlo algorithms for calculation of diffusive characteristics of an electron avalanche in gases

2016 ◽  
Vol 31 (6) ◽  
Author(s):  
Galiya Z. Lotova
Keyword(s):  
Monte Carlo ◽  
Diffusion Coefficients ◽  
Distribution Density ◽  
High Efficiency ◽  
Time Moment ◽  
Three Dimensional ◽  
Electron Avalanche ◽  
Monte Carlo Algorithms ◽  
And Diffusion ◽  
Projection Estimators

AbstractSome problems of the theory of electron transfer in gases under the action of a strong external electric field is considered in the paper. Based on the three-dimensional ELSHOW algorithm, samples of states of particles in an electron avalanche are obtained for a given time moment in order to calculate the corresponding ‘diffusion radii’ and diffusion coefficients. Randomized projection estimators and kernel estimators (for test purpose) are constructed with the use of grouped samples for evaluation of the distribution density of particles in an avalanche. Test computations demonstrate a high efficiency of projection estimators for calculation of diffusive characteristics.

Oxidation Parameters of Oxide Dispersion-Strengthened Steels in Supercritical Water

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Sami Penttilä ◽  
Iva Betova ◽  
Martin Bojinov ◽  
Petri Kinnunen ◽  
Aki Toivonen
Keyword(s):  
Supercritical Water ◽  
Diffusion Coefficients ◽  
Oxide Dispersion Strengthened ◽  
Oxide Dispersion ◽  
Depth Profiles ◽  
Bulk Substrate ◽  
Ods Alloys ◽  
Constituent Elements ◽  
Oxidation Parameters ◽  
And Diffusion

The kinetic parameters of oxidation of two oxide dispersion strengthened (ODS) alloys, PM2000 and MA956, in supercritical water (SCW) are evaluated using an updated model that assumes that the growth of the outer layer is governed by the transport of interstitial cations through the inner layer. The model is able to reproduce quantitatively the depth profiles of individual constituent elements in the inner and outer layers, as well as in the diffusion/transition layer of the alloy between the inner layer and the bulk substrate. The rate constants and diffusion coefficients decrease with time, indicating oxide layer restructuring.

scholarly journals Monte Carlo Calculation of High Frequency Mobility and Diffusion Noise in Nitride-Based Semiconductors

2005 ◽  
Vol 107 (2) ◽  
pp. 408-411
Author(s):  
E. Starikov ◽  
P. Shiktorov ◽  
V. Gružinskis ◽  
L. Varani ◽  
J.C. Vaissière ◽  
...  
Keyword(s):  
Monte Carlo ◽  
High Frequency ◽  
Monte Carlo Calculation ◽  
And Diffusion

Monte Carlo calculation of the energy parameters and spatial distribution of the cathodic arc ions while passing through the macro-particles filters

2018 ◽  
Vol 1 (1) ◽  
pp. 30-34 ◽  
Author(s):  
Alexey Chernogor ◽  
Igor Blinkov ◽  
Alexey Volkhonskiy
Keyword(s):  
Magnetic Field ◽  
Mass Transfer ◽  
Monte Carlo ◽  
Monte Carlo Calculation ◽  
Inhomogeneous Magnetic Field ◽  
Flow Energy ◽  
Wide Range ◽  
Field Concentrator ◽  
Cathodic Arc ◽  
The Magnetic Field

The flow, energy distribution and concentrations profiles of Ti ions in cathodic arc are studied by test particle Monte Carlo simulations with considering the mass transfer through the macro-particles filters with inhomogeneous magnetic field. The loss of ions due to their deposition on filter walls was calculated as a function of electric current and number of turns in the coil. The magnetic field concentrator that arises in the bending region of the filters leads to increase the loss of the ions component of cathodic arc. The ions loss up to 80 % of their energy resulted by the paired elastic collisions which correspond to the experimental results. The ion fluxes arriving at the surface of the substrates during planetary rotating of them opposite the evaporators mounted to each other at an angle of 120° characterized by the wide range of mutual overlapping.

Sign in / Sign up

Export Citation Format

Share Document