The Binary Spatial Partitioning Algorithm for Efficient Tracing of Rays in the Monte Carlo Method for Surface-to-Surface Radiation Transport

2006 ◽  
Author(s):  
Sandip Mazumder
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Binary Tree ◽  
Radiation Transport ◽  
Three Dimensional ◽  
Surface Radiation ◽  
Computational Domain ◽  
Spatial Partitioning ◽  
The Monte Carlo Method ◽  
Discrete Surface

The Binary Spatial Partitioning (BSP) algorithm has found prolific usage within the computer graphics community for efficient tracing of rays. In this paper, the BSP algorithm is described and demonstrated in the context of the Monte Carlo method for surface-to-surface radiation transport. In the BSP algorithm the computational domain is recursively bisected into a set of hierarchically linked boxes that are then made use of to narrow down the number of ray-surface intersection calculations. The geometric information pertaining to these hierarchically linked boxes is stored in the form of a binary tree or table. The algorithm is tested for two classical problems, namely an open box, and a box in a box, in both two-dimensional (2D) and three-dimensional (3D) geometries with various mesh sizes, and is found to result in orders of magnitude gains in computational efficiency over direct calculations that do not employ any acceleration strategy. In theory, the BSP algorithm is expected to scale logarithmically, i.e., the CPU time is expected to increase logarithmically with increase in the number of discrete surface elements (or faces) that the boundaries of the computational domain are broken into. In practice, however, it was found that balancing of the binary tree is critical for logarithmic scaling of the algorithm. Without balancing of the binary tree, only super-linear scaling can be attained.

Methods to Accelerate Ray Tracing in the Monte Carlo Method for Surface-to-Surface Radiation Transport

2006 ◽  
Vol 128 (9) ◽  
pp. 945-952 ◽  
Author(s):  
Sandip Mazumder
Keyword(s):  
Monte Carlo ◽  
Ray Tracing ◽  
Radiation Transport ◽  
Three Dimensional ◽  
Intersection Point ◽  
Surface Radiation ◽  
Computational Domain ◽  
Two Dimensional ◽  
Spatial Partitioning ◽  
The Monte Carlo Method

Two different algorithms to accelerate ray tracing in surface-to-surface radiation Monte Carlo calculations are investigated. The first algorithm is the well-known binary spatial partitioning (BSP) algorithm, which recursively bisects the computational domain into a set of hierarchically linked boxes that are then made use of to narrow down the number of ray-surface intersection calculations. The second algorithm is the volume-by-volume advancement (VVA) algorithm. This algorithm is new and employs the volumetric mesh to advance the ray through the computational domain until a legitimate intersection point is found. The algorithms are tested for two classical problems, namely an open box, and a box in a box, in both two-dimensional (2D) and three-dimensional (3D) geometries with various mesh sizes. Both algorithms are found to result in orders of magnitude gains in computational efficiency over direct calculations that do not employ any acceleration strategy. For three-dimensional geometries, the VVA algorithm is found to be clearly superior to BSP, particularly for cases with obstructions within the computational domain. For two-dimensional geometries, the VVA algorithm is found to be superior to the BSP algorithm only when obstructions are present and are densely packed.

scholarly journals Safety Evaluation of Underground Caverns Based on Monte Carlo Method

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Qifeng Guo ◽  
Zhihong Dong ◽  
Meifeng Cai ◽  
Fenhua Ren ◽  
Jiliang Pan
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Three Dimensional ◽  
Safety Evaluation ◽  
Cumulative Distribution ◽  
Three Dimensional Model ◽  
Maximum Displacement ◽  
The Monte Carlo Method ◽  
Underground Caverns ◽  
The Stability

In order to study the influence of joint fissures and rock parameters with random characteristics on the safety of underground caverns, several parameters affecting the stability of surrounding rock of underground caverns are selected. According to the Monte Carlo method, random numbers satisfying normal distribution characteristics are established. A three-dimensional model of underground caverns with random characteristics is established by discontinuous analysis software 3DEC and excavation simulations are carried out. The maximum displacement at the numerical monitoring points of arch and floor is the safety evaluation index of the cavern. The probability distribution and cumulative distribution function of the displacement at the top arch and floor are obtained, and the safety of a project is evaluated.

scholarly journals Validating a virtual source model based in Monte Carlo method for profiles and percent depth doses calculation

2019 ◽  
Vol 7 (2A) ◽  
Author(s):  
Renata Aline Del Nero ◽  
Marcos Vinicius Nakaoka Nakandakari ◽  
Hélio Yoriyaz
Keyword(s):  
Monte Carlo ◽  
Phase Space ◽  
Monte Carlo Method ◽  
Radiation Transport ◽  
Medical Physics ◽  
Source Model ◽  
Good Precision ◽  
Virtual Source ◽  
The Monte Carlo Method ◽  
Space Data

The Monte Carlo method for radiation transport has been adapted for medical physics application. More specifically, it has received more attention in clinical treatment planning with the development of more efficient computer simulation techniques. In linear accelerator modeling by the Monte Carlo method, the phase space data file (phsp) is an alternative representation for radiation source. However, to create a phase space file and obtain good precision in the results, it is necessary detailed information about the accelerator's head and commonly the supplier does not provide all the necessary data. An alternative to the phsp is the Virtual Source Model (VSM). This alternative approach presents many advantages for the clinical Monte Carlo application. This is the most efficient method for particle generation and can provide an accuracy similar when the phsp is used. This research propose a VSM simulation with the use of a Virtual Flattening Filter (VFF) for profiles and percent depth doses calculation. Two different sizes of open fields (40 x 40 cm² and 40 x 40 cm² rotated 45°) were used and two different source to surface distance (SSD) were applied: the standard 100 cm and custom SSD of 370 cm, which is applied in radiotherapy treatments of total body irradiation. The data generated by the simulation was analyzed and compared with experimental data to validate the VSM. This current model is easy to build and test.

SIMULATION OF GAS RELEASE FLOWS FROM THE FLOW SURFACES OF TURBOMOLECULAR VACUUM PUMPS

2020 ◽  
pp. 45-48
Author(s):  
M. V. Fomin ◽  
I. M. Fomina
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Gas Flow ◽  
Three Dimensional ◽  
Low Density ◽  
Gas Release ◽  
The Monte Carlo Method ◽  
Turbomolecular Pump ◽  
Flow Part

An algorithm for modeling and an example of calculating gas release flows from the surfaces of the flow part of a turbomolecular pump by the Monte Carlo method in a three-dimensional setting low-density gas flow is considered.

Mathematical verification of the Monte Carlo maximum cross-section technique

2015 ◽  
Vol 21 (4) ◽  
Author(s):  
Victor S. Antyufeev
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Cross Section ◽  
Path Length ◽  
Radiation Transport ◽  
Free Path Length ◽  
Maximum Cross Section ◽  
The Monte Carlo Method ◽  
Section Technique ◽  
Probabilistic Proof

AbstractMaximum cross-section technique is used for solving problems of radiation transport by the Monte Carlo method to optimize the particles' free-path length modeling in inhomogeneous media. A probabilistic proof of a variation of this technique is proposed in the article.

Sign in / Sign up

Export Citation Format

Share Document