다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Geant4 is a software toolkit for the simulation of the passage of particles through matter. It is used by a large number of experiments and projects in a variety of application domains, including high energy physics, astrophysics and space science, medical physics and radiation protection. Over the past several years, major changes have been made to the toolkit in order to accommodate the needs of these user communities, and to efficiently exploit the growth of computing power made available by advances in technology. The adaptation of Geant4 to multithreading, advances in physics, detector modeling and visualization, extensions to the toolkit, including biasing and reverse Monte Carlo, and tools for physics and release validation are discussed here.

/pdf/recent-developments-in-geant4-3pgbpf1ko3.pdf

Recent developments in GEANT4

The computer code system PENELOPE (version 2008) performs Monte Carlo simulation of coupled
electron-photon transport in arbitrary materials for a wide energy range, from a few hundred eV to
about 1 GeV. Photon transport is simulated by means of the standard, detailed simulation scheme.
Electron and positron histories are generated on the basis of a mixed procedure, which combines
detailed simulation of hard events with condensed simulation of soft interactions. A geometry package
called PENGEOM permits the generation of random electron-photon showers in material systems
consisting of homogeneous bodies limited by quadric surfaces, i.e., planes, spheres, cylinders, etc. This
report is intended not only to serve as a manual of the PENELOPE code system, but also to provide the
user with the necessary information to understand the details of the Monte Carlo algorithm.

/pdf/penelope-2006-a-code-system-for-monte-carlo-simulation-of-43nx3zmw6c.pdf

PENELOPE-2006: A Code System for Monte Carlo Simulation of Electron and Photon Transport

As the scale and complexity of High Energy Physics experiments increase, simulation studies require more and more care and become essential to design and optimise the detectors, develop and test the reconstruction and analysis programs, and interpret the experimental data. GEANT is a system of detector description and simulation tools that help physicists in such studies.

/pdf/geant-detector-description-and-simulation-tool-4bwixv478q.pdf

GEANT Detector Description and Simulation Tool

We have upgraded many features of the Particle and Heavy Ion Transport code System (PHITS) and released the new version as PHITS3.02. The accuracy and the applicable energy ranges of the code were ...

https://www.tandfonline.com/doi/pdf/10.1080/00223131.2017.1419890

Features of Particle and Heavy Ion Transport code System (PHITS) version 3.02

The Egs4 Code System

In the nineteen years since EGS4 was released, it has been used in a wide variety of applications, particularly in medical physics, radiation measurement studies, and industrial development. Every new user and every new application bring new challenges for Monte Carlo code designers, and code refinements and bug fixes eventually result in a code that becomes difficult to maintain. Several of the code modifications represented significant advances in electron and photon transport physics, and required a more substantial invocation than code patching. Moreover, the arcane MORTRAN3[48] computer language of EGS4, was highest on the complaint list of the users of EGS4. The size of the EGS4 user base is difficult to measure, as there never existed a formal user registration process. However, some idea of the numbers may be gleaned from the number of EGS4 manuals that were produced and distributed at SLAC: almost three thousand. Consequently, the EGS5 project was undertaken. It was decided to employ the FORTRAN 77 compiler, yet include as much as possible, the structural beauty and power of MORTRAN3. This report consists of four chapters and several appendices. Chapter 1 is an introduction to EGS5 and to this report in general. We suggest that youmore » read it. Chapter 2 is a major update of similar chapters in the old EGS4 report[126] (SLAC-265) and the old EGS3 report[61] (SLAC-210), in which all the details of the old physics (i.e., models which were carried over from EGS4) and the new physics are gathered together. The descriptions of the new physics are extensive, and not for the faint of heart. Detailed knowledge of the contents of Chapter 2 is not essential in order to use EGS, but sophisticated users should be aware of its contents. In particular, details of the restrictions on the range of applicability of EGS are dispersed throughout the chapter. First-time users of EGS should skip Chapter 2 and come back to it later if necessary. With the release of the EGS4 version, a deliberate attempt was made to present example problems in order to help the user ''get started'', and we follow that spirit in this report. A series of elementary tutorial user codes are presented in Chapter 3, with more sophisticated sample user codes described in Chapter 4. Novice EGS users will find it helpful to read through the initial sections of the EGS5 User Manual (provided in Appendix B of this report), proceeding then to work through the tutorials in Chapter 3. The User Manuals and other materials found in the appendices contain detailed flow charts, variable lists, and subprogram descriptions of EGS5 and PEGS. Included are step-by-step instructions for developing basic EGS5 user codes and for accessing all of the physics options available in EGS5 and PEGS. Once acquainted with the basic structure of EGS5, users should find the appendices the most frequently consulted sections of this report.« less

The EGS5 code system

A modification to the general-purpose Monte Carlo electron-photon transport code EGS4 [1] was made in order to include Doppler broadening of Compton-scattered photon energy due to electron pre-collision motion. The Compton-scattered photon energy is sampled from a cross section formula based on the Compton profile, and the Compton scattering is sustained if the energy imparted to the electron is less than its binding energy. The electron binding effect modifies the scattered photon energy, angular distribution, and total cross section of the Compton scattering, and affects the photon mean free path used in the calculations. In the improved EGS4 code, all of these electron binding effects in Compton scattering are treated consistently. A simulation of 40 keV photon scattering by C and Cu samples was performed using the improved EGS4 code; the calculated scattered photon spectra agreed well with the measurements.

/pdf/implementation-of-the-doppler-broadening-of-a-compton-18dvx191eb.pdf

Implementation of the Doppler broadening of a Compton-scattered photon into the EGS4 code

A modification to the general-purpose Monte Carlo electron-photon transport code EGS4 [Nelson, Hirayama and Rogers, SLAC-265] was made in order to include linear polarization in the simulation of photon scattering. Both the Compton and Rayleigh scattering routines were modified to properly account for the electric-field vector of the photon. This vector is calculated at each photon scatter, and is passed along with the photons in the radiation transport, thereby allowing for a precise simulation of polarized multiple scattering. A simulation of the absorbed-dose distribution in a soft tissue equivalent phantom for a linearly polarized incident photon beam, scattering many times, was successfully performed.

Implementation of linearly-polarized photon scattering into the EGS4 code

A radiation damage effect on silicon strip detectors of pn-junction type is investigated using a high energy proton beam. In order to clarify the cause of leakage current increase, several variations of strip detectors with different surface structures were made and tested. No appreciable differences in leakage current increase are observed among these samples. A strong temperature dependence on leakage current is observed. This can be explained by a formation of radiation induced trap energy levels in the bulk silicon. A moderate room temperature annealing is seen. A pulse height degradation of about 10–20% is observed at a few Mrad of radiation. Some implications of the present results are discussed for possible application of silicon semiconductor detectors in future high energy hadron colliders.

Hideo Hirayama

Papers

The Egs4 Code System

The EGS5 code system

Implementation of the Doppler broadening of a Compton-scattered photon into the EGS4 code

Implementation of linearly-polarized photon scattering into the EGS4 code

Radiation damage in silicon microstrip detectors