G eant 4 is a toolkit for simulating the passage of particles through matter. It includes a complete range of functionality including tracking, geometry, physics models and hits. The physics processes offered cover a comprehensive range, including electromagnetic, hadronic and optical processes, a large set of long-lived particles, materials and elements, over a wide energy range starting, in some cases, from 250 eV and extending in others to the TeV energy range. It has been designed and constructed to expose the physics models utilised, to handle complex geometries, and to enable its easy adaptation for optimal use in different sets of applications. The toolkit is the result of a worldwide collaboration of physicists and software engineers. It has been created exploiting software engineering and object-oriented technology and implemented in the C++ programming language. It has been used in applications in particle physics, nuclear physics, accelerator design, space engineering and medical physics.

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Geant4—a simulation toolkit

Geant4 - A Simulation Toolkit

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.

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Recent developments in GEANT4

ENDF/B-VII.1 Nuclear Data for Science and Technology: Cross Sections, Covariances, Fission Product Yields and Decay Data

The fourth version of the Japanese Evaluated Nuclear Data Library has been produced in cooperation with the Japanese Nuclear Data Committee. In the new library, much emphasis is placed on the impro...

https://www.tandfonline.com/doi/pdf/10.1080/18811248.2011.9711675

JENDL-4.0: A New Library for Nuclear Science and Engineering

The revision work of JENDL-3 has been made by considering feedback information of various benchmark tests. The main revised quantities are the resonance parameters, capture and inelastic scattering cross sections, and fission spectra of main actinide nuclides, the total and inelastic scattering cross sections of structural materials, the resonance parameters the capture and inelastic scattering cross sections of fission products, and the γ-ray production data. The revised data were released as JENDL-3.2 in June 1994. The preliminary benchmark tests indicate that JENDL-3.2 predicts various reactor characteristics more successfully than the previous version of JENDL-3.1.

https://www.tandfonline.com/doi/pdf/10.1080/18811248.2002.9715303

Japanese evaluated nuclear data library version 3 revision-3: JENDL-3.3

In order to identify the origin of the ubiquitous and long-standing discrepancy seen in the γ-ray component of the FP decay heat in the cooling time range 300-3,000 s, a comprehensive analysis of the differences between the summation calculations and the experiments has been carried out. There may be some missing of the β-strength in the high energy region of the FPs in the mass region A=100-110. Especially, 102Tc, 104Tc, 105Tc and 108Rh are potentially responsible for the γ-ray discrepancy seen in the three major fissioning nuclides, 235U, 238U and 239Pu, systematically. The β-strength functions are theoretically calculated in order to validate this possibility. It is proved that the chance for finding the additional β-strength required to solve the discrepancy is not so large but still exists, and the exact β-feed from Tc to the highly excited levels in Rb should be identified experimentally. Finally, the impact of the β-ray discrepancy on the reactor-core decay heat is evaluated quantitatively for the ...

https://www.tandfonline.com/doi/pdf/10.1080/18811248.1999.9726191

Possible Origin of the Gamma-ray Discrepancy in the Summation Calculations of Fission Product Decay Heat

Delayed neutron data of 235U, 238U and 239Pu have been evaluated and recommended for JENDL-3.3. Adjustment of Vd was carried out on the basis of the seff measurements at FCA, MASURCA and TCA using the JENDL-3.2 data as the initial guess. Through this adjustment the vd value for 238U below 3.5 MeV was decreased by about 3 % from 0.0481 to 0.0466. The vd values of 235U and 239Pu were also determined in this way. Further appropriate six group constants, the decay constants λi and the group yields αi, were determined from experimental data of the delayed neutron emission rates, which were collected and compiled by Spriggs through the SG6 activity of WPEC. Applicability of the resultant group constants was validated through the analyses of the reactivity measurements based on the period or the rod-drop methods.

Evaluation of delayed neutron data for JENDL-3.3

Beta- and gamma-ray spectra of fission product nuclides were estimated by a theoretical model for the nuclides having no or incompletely measured spectral data. The estimation was performed with Gross Theory of Beta Decay. The estimated spectra were so stored in JENDL FP Decay Data File 2000 as to keep the consistency between the average decay energy value derived from the spectrum and that used for decay heat analysis. The JENDL spectra of FP nuclides and the aggregate beta- and gamma-ray spectra of fission product nuclides calculated using the JENDL spectra showed good agreement with measured data.

https://www.tandfonline.com/doi/pdf/10.1080/18811248.2001.9715056

Jun Ichi Katakura

Papers

Japanese evaluated nuclear data library version 3 revision-3: JENDL-3.3

Possible Origin of the Gamma-ray Discrepancy in the Summation Calculations of Fission Product Decay Heat

Evaluation of delayed neutron data for JENDL-3.3

Estimation of Beta- and Gamma-Ray Spectra for JENDL FP Decay Data File