Study of the high-frequency performance of III-As nanojunctions using a three-dimensional ensemble Monte Carlo model

To describe [Formula: see text] interactions with production of three [Formula: see text]-particles at incident neutron kinetic energy of 14 MeV in a nuclear (photo) emulsion, a Monte Carlo model is proposed for four channels of decay of an excited carbon-12 nucleus into three [Formula: see text]-particles. The Monte Carlo calculation results describe well the experimental data on the distribution of the angle between the three-dimensional momenta of all pairs of [Formula: see text]-particles in a collision event, on the distribution of the angle between the projections of the momentum vectors of all pairs of [Formula: see text]-particles in collision event on each of the coordinate planes, on the distribution of the sum of the kinetic energies of all pairs of [Formula: see text]-particles in a collision event, and the distribution of projections of the momenta of [Formula: see text]-particles on the coordinate planes. The best agreement of the Monte Carlo model results with the experimental data is achieved if the direct decay [Formula: see text] and decay through the formation of an intermediate beryllium nucleus [Formula: see text] are generated with equal probabilities, while the excitation energies of 3.04 MeV, 1.04 MeV, and 0.1 MeV for the beryllium nucleus are generated with relative weights of 75%, 15%, and 10%, respectively.

Download Full-text

A 3D particle Monte Carlo approach to studying nucleation

10.5194/acp-2017-269 ◽

2017 ◽

Author(s):

Christoph Köhn ◽

Martin Bødker Enghoff ◽

Henrik Svensmark

Keyword(s):

Monte Carlo ◽

Sulphuric Acid ◽

Nucleation Rate ◽

Particle Density ◽

Monte Carlo Model ◽

Three Dimensional ◽

Initial Particle ◽

Time Step ◽

Size Dependent ◽

Discrete Nature

Abstract. The nucleation of sulphuric acid molecules plays a key role in the formation of aerosols. We here present a three dimensional particle Monte Carlo model to study the growth of sulphuric acid clusters as well as its dependence on the ambient temperature and the initial particle density.We initiate a swarm of sulphuric acid molecules with a size of 0.15 nm with densities between 107 and 108 cm−3 at temperatures of 200 and 300 K. After every time step, we update the position and velocity of particles as a function of size-dependent diffusion coefficients. If two particles encounter, we merge them and add their volumes and masses. Inversely, we check after every time step whether a polymer evaporates liberating a molecule.We present the spatial distribution as well as the size distribution calculated from individual clusters. We also calculate the nucleation rate of clusters with a radius of 0.85 nm as a function of time, initial particle density and temperature. For 200 K, the nucleation rate increases as a function of time; for 300 K we observe an interplay between clustering and evaporation and thus the oscillation of the nucleation rate around the mean nucleation rate. The nucleation rates obtained from the presented model agree well with experimentally obtained values which serves as a benchmark of our code. In contrast to previous nucleation models, we here present for the first time a code capable of tracing individual particles and thus of capturing the physics related to the discrete nature of particles.

Download Full-text

Self-learning kinetic Monte Carlo model for arbitrary surface orientations

MRS Proceedings ◽

10.1557/opl.2013.691 ◽

2013 ◽

Vol 1559 ◽

Cited By ~ 1

Author(s):

Andreas Latz ◽

Lothar Brendel ◽

Dietrich E. Wolf

Keyword(s):

Monte Carlo ◽

Specific Surface ◽

Kinetic Monte Carlo ◽

Monte Carlo Model ◽

Three Dimensional ◽

The Self ◽

Transition Rates ◽

Local Orientation ◽

Realistic Potential ◽

Self Learning

ABSTRACTWhile the self-learning kinetic Monte Carlo (SLKMC) method enables the calculation of transition rates from a realistic potential, implementations of it were usually limited to one specific surface orientation. An example is the fcc (111) surface in Latz et al. 2012, J. Phys.: Condens. Matter 24, 485005. This work provides an extension by means of detecting the local orientation, and thus allows for the accurate simulation of arbitrarily shaped surfaces. We applied the model to the diffusion of Ag monolayer islands and voids on a Ag(111) and Ag(001) surface, as well as the relaxation of a three-dimensional spherical particle.

Download Full-text

A Three-Dimensional Monte Carlo Model for Phosphorus Implants into (100) Single-Crystal Silicon

MRS Proceedings ◽

10.1557/proc-490-33 ◽

1997 ◽

Vol 490 ◽

Author(s):

Myung-Sik Son ◽

Ho-Jung Hwang

Keyword(s):

Monte Carlo ◽

Single Crystal ◽

Room Temperature ◽

Monte Carlo Model ◽

Three Dimensional ◽

Single Crystal Silicon ◽

Amorphous Region ◽

Electronic Energy ◽

Crystal Silicon ◽

Dynamic Simulation Model

ABSTRACTAn alternative three-dimensional (3D) Monte Carlo (MC) dynamic simulation model for phosphorus implant into (100) single-crystal silicon has been developed which incorporates the effects of channeling and damage. This model calculates the trajectories of both implanted ions and recoiled silicons and concurrently and explicitly affects both ions and recoils due to the presence of accumulative damage. In addition, the model for room-temperature implant accounts for the self-annealing effect using our defined recombination probabilities for vacancies and interstitials saved on the unit volumes. Our model has been verified by the comparison with the previously published SIMS data over commonly used energy range between 10 and 180 keV, using our proposed empirical electronic energy loss model. The 3D formations of the amorphous region and the ultra-shallow junction around the implanted region could be predicted by using our model, TRICSI (TRansport Ions into Crystal-Silicon).

Download Full-text

Ensemble Monte Carlo Study of Electron Transport in Bulk Indium Nitride

MRS Internet Journal of Nitride Semiconductor Research ◽

10.1557/s1092578300003410 ◽

1999 ◽

Vol 4 (S1) ◽

pp. 781-786

Author(s):

E. Bellotti ◽

B. Doshi ◽

K. F. Brennan ◽

P. P. Ruden

Keyword(s):

Monte Carlo ◽

Electron Transport ◽

Model Comparison ◽

Phonon Scattering ◽

Impact Ionization ◽

Indium Nitride ◽

Monte Carlo Model ◽

Breakdown Field ◽

Ensemble Monte Carlo ◽

Full Band

Ensemble Monte Carlo calculations of electron transport at high applied electric field strengths in bulk, wurtzite phase InN are presented. The calculations are performed using a full band Monte Carlo simulation that includes a pseudopotential band structure, all of the relevant phonon scattering agents, and numerically derived impact ionization transition rates. The full details of the first five conduction bands, which extend in energy to about 8 eV above the conduction band minimum, are included in the simulation. The electron initiated impact ionization coefficients and quantum yield are calculated using the full band Monte Carlo model. Comparison is made to previous calculations for bulk GaN and ZnS. It is found that owing to the narrower band gap in InN, a lower breakdown field exists than in either GaN or ZnS.

Download Full-text