Monte Carlo N-Particle Transport Code

Last updated
MCNP
Developer(s) LANL
Stable release
MCNP6.3 / January 10, 2023;11 months ago (2023-01-10) [1]
Written in Fortran 90
Operating system Cross-platform
Type Computational physics
License https://rsicc.ornl.gov/
Website mcnp.lanl.gov

Monte Carlo N-Particle Transport (MCNP) [2] is a general-purpose, continuous-energy, generalized-geometry, time-dependent, Monte Carlo radiation transport code designed to track many particle types over broad ranges of energies and is developed by Los Alamos National Laboratory. Specific areas of application include, but are not limited to, radiation protection and dosimetry, radiation shielding, radiography, medical physics, nuclear criticality safety, detector design and analysis, nuclear oil well logging, accelerator target design, fission and fusion reactor design, decontamination and decommissioning. The code treats an arbitrary three-dimensional configuration of materials in geometric cells bounded by first- and second-degree surfaces and fourth-degree elliptical tori.

Contents

Point-wise cross section data are typically used, although group-wise data also are available. For neutrons, all reactions given in a particular cross-section evaluation (such as ENDF/B-VI) are accounted for. Thermal neutrons are described by both the free gas and S(α,β) models. For photons, the code accounts for incoherent and coherent scattering, the possibility of fluorescent emission after photoelectric absorption, absorption in pair production with local emission of annihilation radiation, and bremsstrahlung. A continuous-slowing-down model is used for electron transport that includes positrons, k x-rays, and bremsstrahlung but does not include external or self-induced fields.

Important standard features that make MCNP very versatile and easy to use include a powerful general source, criticality source, and surface source; both geometry and output tally plotters; a rich collection of variance reduction techniques; a flexible tally structure; and an extensive collection of cross-section data.

MCNP contains numerous flexible tallies: surface current and flux, volume flux (track length), point or ring detectors, particle heating, fission heating, pulse height tally for energy or charge deposition, mesh tallies, and radiography tallies.

The key value MCNP provides is a predictive capability that can replace expensive or impossible-to-perform experiments. It is often used to design large-scale measurements providing a significant time and cost savings to the community. LANL's latest version of the MCNP code, version 6.2, represents one piece of a set of synergistic capabilities each developed at LANL; it includes evaluated nuclear data (ENDF) and the data processing code, NJOY. The international user community's high confidence in MCNP's predictive capabilities are based on its performance with verification and validation test suites, comparisons to its predecessor codes, automated testing, underlying high quality nuclear and atomic databases and significant testing by its users.

History

The Monte Carlo method for radiation particle transport has its origins at LANL dates back to 1946. [3] The creators of these methods were Stanislaw Ulam, John von Neumann, Robert Richtmyer, and Nicholas Metropolis. [4] Monte Carlo for radiation transport was conceived by Stanislaw Ulam in 1946 while playing Solitaire while recovering from an illness. "After spending a lot of time trying to estimate success by combinatorial calculations, I wondered whether a more practical method...might be to lay it out say one hundred times and simply observe and count the number of successful plays." In 1947, John von Neumann sent a letter to Robert Richtmyer proposing the use of a statistical method to solve neutron diffusion and multiplication problems in fission devices. [5] His letter contained an 81-step pseudo code and was the first formulation of a Monte Carlo computation for an electronic computing machine. Von Neumann's assumptions were: time-dependent, continuous-energy, spherical but radially-varying, one fissionable material, isotropic scattering and fission production, and fission multiplicities of 2, 3, or 4. He suggested 100 neutrons each to be run for 100 collisions and estimated the computational time to be five hours on ENIAC [6] [ circular reference ]. Richtmyer proposed suggestions to allow for multiple fissionable materials, no fission spectrum energy dependence, single neutron multiplicity, and running the computation for computer time and not for the number of collisions. The code was finalized in December 1947. The first calculations were run in April/May 1948 on ENIAC.

While waiting for ENIAC to be physically relocated, Enrico Fermi invented a mechanical device called FERMIAC [7] to trace neutron movements through fissionable materials by the Monte Carlo method. Monte Carlo methods for particle transport have been driving computational developments since the beginning of modern computers; this continues today.

In the 1950s and 1960s, these new methods were organized into a series of special-purpose Monte Carlo codes, including MCS, MCN, MCP, and MCG. These codes were able to transport neutrons and photons for specialized LANL applications. In 1977, these separate codes were combined to create the first generalized Monte Carlo radiation particle transport code, MCNP. [8] [9] In 1977, MCNP was first created by merging MCNG with MCP to create MCNP. The first release of the MCNP code was version 3 and was released in 1983. It is distributed by the Radiation Safety Information Computational Center in Oak Ridge, TN.

Monte Carlo N-Particle eXtended

Monte Carlo N-Particle eXtended (MCNPX) was also developed at Los Alamos National Laboratory, and is capable of simulating particle interactions of 34 different types of particles (nucleons and ions) and 2000+ heavy ions at nearly all energies, [10] including those simulated by MCNP.

Both codes can be used to judge whether or not nuclear systems are critical and to determine doses from sources, among other things.

MCNP6 is a merger of MCNP5 and MCNPX. [10]

Comparison

MCNP6 is less accurate than MCNPX. [11] [12] Geant4 is less accurate than MCNPX. [11] [12] [13] [14] [15] Geant4 is less accurate than MCNP5. [12] [16]

Geant4 is slower than MCNPX. [12] [13] [17]

See also

Notes

  1. ↑ "MCNP6.3 Release notes" (PDF). LANL. 2023-01-10. Retrieved 2024-01-09.
  2. ↑ "MCNP Website".
  3. ↑ Sood, A. (July 2017). "The Monte Carlo Method and MCNP –A Brief Review of Our 40 Year History" (PDF). MCNP Website - references section.
  4. ↑ Eckhardt, R. (1987). "Stan Ulam, John Von Neumann, and the Monte Carlo Method" (PDF). MCNP Website - reference section.
  5. ↑ von Neumann, J. (1947). "Statistical Methods in Neutron Diffusion" (PDF).
  6. ↑ "ENIAC". Wikipedia.
  7. ↑ "FERMIAC", Wikipedia, 2019-08-28, retrieved 2020-01-09
  8. ↑ Carter, L.L. (March 1975). "Monte Carlo Code Development in Los Alamos" (PDF). MCNP Website - reference section.
  9. ↑ "Proceedings of the NEACRP Meeting Of A Monte Carlo Study Group" (PDF). OECD-NEA archives. July 1974.
  10. 1 2 James, M.R. "MCNPX 2.7.x - New Features Being Developed" (PDF).
  11. 1 2 Mesick, K. E.; Feldman, W. C.; Coupland, D. D. S.; Stonehill, L. C. (2018). "Benchmarking Geant4 for Simulating Galactic Cosmic Ray Interactions Within Planetary Bodies". Earth and Space Science. 5 (7): 324–338. arXiv: 1810.06483 . doi:10.1029/2018EA000400.
  12. 1 2 3 4 Gloster, Colin Paul (2023). "Comment on "Gamma-ray spectroscopy using angular distribution of Compton scattering" [Nucl. Instr. and Meth. A 1031 (2022) 166502]". Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 1049: 167923. doi:10.1016/j.nima.2022.167923. S2CID   255262511.
  13. 1 2 Affonso, Werneck; Raoni, Renato; Mattos Barbosa, Caroline; Dam, Roos S.F.; Salgado, William L.; X. da Silva, Ademir; M. Salgado, César (2020). "Comparison between codes MCNPX and Gate/Geant4 in volume fraction studies". Applied Radiation and Isotopes. 164: 109226. doi:10.1016/j.apradiso.2020.109226.
  14. ↑ van der Ende, B.M.; Atanackovic, J.; Erlandson, A.; Bentoumi, G. (2016). "Use of GEANT4 vs. MCNPX for the characterization of a boron-lined neutron detector". Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 820: 40–47. doi: 10.1016/j.nima.2016.02.082 .
  15. ↑ Ferrari, Alfredo; Kiselev, Daniela; Koi, Tatsumi; Wohlmuther, Michael; Davide, Jean-Christophe (2018). "Po-production in lead: A benchmark between Geant4, FLUKA and MCNPX". arXiv: 1806.03732 [physics.acc-ph].
  16. ↑ Almatari, M.; Issa, Shams A.M.; Dong, M.G.; Sayyed, M.I.; Ayad, R. (2019). "Comparison between MCNP5, Geant4 and experimental data for gamma rays attenuation of PbO-BaO-B2O3 glasses". Heliyon. 5 (8): e02364. doi:10.1016/j.heliyon.2019.e02364. PMC   6716400 . PMID   31485541.
  17. ↑ Randeniya, S. D.; Taddei, P. J.; Newhauser, W. D.; Yepes, P. (2009). "Intercomparision of Monte Carlo Radiation Transport Codes MCNPX, GEANT4, and FLUKA for Simulating Proton Radiotherapy of the Eye". Nuclear Technology. 168 (3): 810–814. doi:10.13182/NT09-A9310. PMC   2943388 . PMID   20865141.

Related Research Articles

<span class="mw-page-title-main">Neutron</span> Subatomic particle with no charge

The neutron is a subatomic particle, symbol
n
 or
n0
, which has a neutral charge, and a mass slightly greater than that of a proton. Protons and neutrons constitute the nuclei of atoms. Since protons and neutrons behave similarly within the nucleus, and each has a mass of approximately one dalton, they are both referred to as nucleons. Their properties and interactions are described by nuclear physics. Protons and neutrons are not elementary particles; each is composed of three quarks.

<span class="mw-page-title-main">Stanisław Ulam</span> Polish mathematician and physicist (1909–1984)

Stanisław Marcin Ulam was a Polish-American mathematician, nuclear physicist and computer scientist. He participated in the Manhattan Project, originated the Teller–Ulam design of thermonuclear weapons, discovered the concept of the cellular automaton, invented the Monte Carlo method of computation, and suggested nuclear pulse propulsion. In pure and applied mathematics, he proved some theorems and proposed several conjectures.

A synthetic radioisotope is a radionuclide that is not found in nature: no natural process or mechanism exists which produces it, or it is so unstable that it decays away in a very short period of time. Examples include technetium-95 and promethium-146. Many of these are found in, and harvested from, spent nuclear fuel assemblies. Some must be manufactured in particle accelerators.

Monte Carlo methods, or Monte Carlo experiments, are a broad class of computational algorithms that rely on repeated random sampling to obtain numerical results. The underlying concept is to use randomness to solve problems that might be deterministic in principle. They are often used in physical and mathematical problems and are most useful when it is difficult or impossible to use other approaches. Monte Carlo methods are mainly used in three problem classes: optimization, numerical integration, and generating draws from a probability distribution.

<span class="mw-page-title-main">Nuclear technology</span> Technology that involves the reactions of atomic nuclei

Nuclear technology is technology that involves the nuclear reactions of atomic nuclei. Among the notable nuclear technologies are nuclear reactors, nuclear medicine and nuclear weapons. It is also used, among other things, in smoke detectors and gun sights.

<span class="mw-page-title-main">Critical mass</span> Smallest amount of fissile material needed to sustain a nuclear reaction

In nuclear engineering, a critical mass is the smallest amount of fissile material needed for a sustained nuclear chain reaction. The critical mass of a fissionable material depends upon its nuclear properties, density, shape, enrichment, purity, temperature, and surroundings. The concept is important in nuclear weapon design.

<span class="mw-page-title-main">Nicholas Metropolis</span> American mathematician

Nicholas Constantine Metropolis was a Greek-American physicist.

<span class="mw-page-title-main">Geant4</span> Scientific software for particle physics

Geant4 is a platform for "the simulation of the passage of particles through matter" using Monte Carlo methods. It is the successor of the GEANT series of software toolkits developed by The Geant4 Collaboration, and the first to use object oriented programming. Its development, maintenance and user support are taken care by the international Geant4 Collaboration. Application areas include high energy physics and nuclear experiments, accelerator and space physics studies. The software is used by a number of research projects around the world.

<span class="mw-page-title-main">Neutron transport</span> Study of motions and interactions of neutrons

Neutron transport is the study of the motions and interactions of neutrons with materials. Nuclear scientists and engineers often need to know where neutrons are in an apparatus, in what direction they are going, and how quickly they are moving. It is commonly used to determine the behavior of nuclear reactor cores and experimental or industrial neutron beams. Neutron transport is a type of radiative transport.

In nuclear engineering, a prompt neutron is a neutron immediately emitted by a nuclear fission event, as opposed to a delayed neutron decay which can occur within the same context, emitted after beta decay of one of the fission products anytime from a few milliseconds to a few minutes later.

Radiation implosion is the compression of a target by the use of high levels of electromagnetic radiation. The major use for this technology is in fusion bombs and inertial confinement fusion research.

<span class="mw-page-title-main">Thermonuclear weapon</span> 2-stage nuclear weapon

A thermonuclear weapon, fusion weapon or hydrogen bomb (H bomb) is a second-generation nuclear weapon design. Its greater sophistication affords it vastly greater destructive power than first-generation nuclear bombs, a more compact size, a lower mass, or a combination of these benefits. Characteristics of nuclear fusion reactions make possible the use of non-fissile depleted uranium as the weapon's main fuel, thus allowing more efficient use of scarce fissile material such as uranium-235 or plutonium-239. The first full-scale thermonuclear test was carried out by the United States in 1952; the concept has since been employed by most of the world's nuclear powers in the design of their weapons.

Naturally occurring zirconium (40Zr) is composed of four stable isotopes (of which one may in the future be found radioactive), and one very long-lived radioisotope (96Zr), a primordial nuclide that decays via double beta decay with an observed half-life of 2.0×1019 years; it can also undergo single beta decay, which is not yet observed, but the theoretically predicted value of t1/2 is 2.4×1020 years. The second most stable radioisotope is 93Zr, which has a half-life of 1.53 million years. Thirty other radioisotopes have been observed. All have half-lives less than a day except for 95Zr (64.02 days), 88Zr (83.4 days), and 89Zr (78.41 hours). The primary decay mode is electron capture for isotopes lighter than 92Zr, and the primary mode for heavier isotopes is beta decay.

The Monte Carlo trolley, or FERMIAC, was an analog computer invented by physicist Enrico Fermi to aid in his studies of neutron transport.

FLUKA is a fully integrated Monte Carlo simulation package for the interaction and transport of particles and nuclei in matter. FLUKA has many applications in particle physics, high energy experimental physics and engineering, shielding, detector and telescope design, cosmic ray studies, dosimetry, medical physics, radiobiology. A recent line of development concerns hadron therapy.

FASTRAD is a tool dedicated to the calculation of radiation effects on electronics. The tool includes a 3d modelling interface with all the capabilities required for the representation of any system. Application areas include: high energy physics and nuclear experiments, medical, accelerator and space physics studies. The software is used by radiation engineers around the world.

The following timeline starts with the invention of the modern computer in the late interwar period.

This is a timeline of key developments in computational mathematics.

Hrvoje Brkić, Croatian biophysicist. He was born in Vinkovci, where he attended elementary school and Gymnasium Matija Antun Reljković. In 2007. he finished Physics department of J. J. Strossmayer University of Osijek, and approached to the PhD in Faculty of natural sciences in Zagreb. PhD thesis named Computational studies of Iron dependent dioxygenases, under mentor prof. Sanja Tomić, was defended in 2014th. Till now has co-authored approximately 30 internationally reviewed scientific papers.

Associated particle imaging (API), sometimes referred to as the tagged neutron method (TNM), is a three dimensional imaging technique that maps the distribution of elements within an object. In associated particle imaging, deuterium-tritium fusion reactions each produce a fast neutron and an associated particle, which travel in opposite directions in the center-of-mass frame. By measuring the timing and position of the associated particle, the trajectory of the neutron may be inferred. The neutron may then enter an object of interest where it is likely to undergo inelastic scattering. This produces one or more gamma-rays of specific energies dependent on the element that the neutron scatters off of. By measuring the gamma-ray energy, the element may be identified. The timing of the gamma-ray coinciding with an associated particle allows the 3D imaging of an object's elemental composition. This technique has applications in agriculture, national security, and diamond detection, among other areas.

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.