Cascade-exciton model of nuclear reactions

Gudima, K. K.; Mashnik, S. G.; Тонеев, В.Д.

doi:10.1016/0375-9474(83)90532-8

Cited by 263 publications

(234 citation statements)

References 33 publications

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“…10) In the case of double-differential spectra of particle emission, both prescriptions lead to similar results, but when trying to reproduce isotope production in typical spallation reactions, 11) the semi-microscopical transition probabilities. 9) produce better results. Therefore, the last one has been chosen as default.…”

Section: Pre-equilibriummentioning

confidence: 96%

“…The transition probabilities (a key ingredient of the model) have been calculated either in a semimicroscopical way. 9) or using a standard parameterization of the matrix elements. 10) In the case of double-differential spectra of particle emission, both prescriptions lead to similar results, but when trying to reproduce isotope production in typical spallation reactions, 11) the semi-microscopical transition probabilities.…”

Section: Pre-equilibriummentioning

confidence: 99%

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Recent Developments in Pre-Equilibrium and De-Excitation Models in Geant4

Quesada

Ivanchenko

et al. 2011

Progress in Nuclear Science and Technology

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Geant4 native pre-equilibrium and de-excitation models are used for sampling of residual nucleus fragmentation in a number of generators of inelastic hadron/ion interaction with nuclei including QGS, FTF, Binary Cascade, QMD and some others. The pre-compound model is responsible for pre-equlibrium emission of protons, neutrons and light ions. The de-excitation model provides sampling of evaporation of neutrons, protons and light fragments up to magnesium, Fermi break-up, statistical multifragmentation, fission and photon emission. Recently a review of the pre-equilibrium and de-excitation models of Geant4 has been performed and we report a summary of modifications introduced. The results of the validation versus various published data are presented.

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Section: Pre-equilibriummentioning

confidence: 96%

Section: Pre-equilibriummentioning

confidence: 99%

Recent Developments in Pre-Equilibrium and De-Excitation Models in Geant4

Quesada

Ivanchenko

et al. 2011

Progress in Nuclear Science and Technology

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“…The cascade-exciton model of nuclear reactions was proposed more than 30 years ago at the Laboratory of Theoretical Physics, JINR, Dubna, USSR by Gudima, Mashnik, and Toneev [3]. It is based on the standard (non time-dependent) Dubna intranuclear cascade model [24,25] and the modified exciton model [26,27].…”

Section: Cem and Laqgsm Overviewmentioning

confidence: 99%

“…The basic versions of both the CEM and LAQGSM event generators are the so-called "03.03" versions, namely CEM03.03 [2][3][4] and LAQGSM03.03 [4][5][6]. The CEM code calculates nuclear reactions induced only by nucleons, pions, and photons.…”

Section: Cem and Laqgsm Overviewmentioning

confidence: 99%

“…The Los Alamos National Laboratory (LANL) MonteCarlo N-particle transport code MCNP6 [1] uses by default the latest version of the cascade-exciton model (CEM), CEM03.03 [2][3][4], as its event generator to simulate reactions induced by nucleons, pions, and photons of energies up to 4.5 GeV and the Los Alamos version of the quark-gluon string model (LAQGSM), LAQGSM03.03 [4][5][6], to simulate such reactions at higher energies, as well as reactions induced by other elementary particles and by nuclei of all energies up to ∼ 1 TeV/nucleon.…”

Section: Introductionmentioning

confidence: 99%

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Production of energetic light fragments in extensions of the CEM and LAQGSM event generators of the Monte Carlo transport code MCNP6

et al. 2017

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We extend the cascade-exciton model (CEM), and the Los Alamos version of the quark-gluon string model (LAQGSM), event generators of the Monte-Carlo N-particle transport code version 6 (MCNP6), to describe production of energetic light fragments (LF) heavier than 4 He from various nuclear reactions induced by particles and nuclei at energies up to about 1 TeV/nucleon. In these models, energetic LF can be produced via Fermi break-up, preequilibrium emission, and coalescence of cascade particles. Initially, we study several variations of the Fermi break-up model and choose the best option for these models. Then, we extend the modified exciton model (MEM) used by these codes to account for a possibility of multiple emission of up to 66 types of particles and LF (up to 28 Mg) at the preequilibrium stage of reactions. Then, we expand the coalescence model to allow coalescence of LF from nucleons emitted at the intranuclear cascade stage of reactions and from lighter clusters, up to fragments with mass numbers A ≤ 7, in the case of CEM, and A ≤ 12, in the case of LAQGSM. Next, we modify MCNP6 to allow calculating and outputting spectra of LF and heavier products with arbitrary mass and charge numbers. The improved version of CEM is implemented into MCNP6. Finally, we test the improved versions of CEM, LAQGSM, and MCNP6 on a variety of measured nuclear reactions. The modified codes give an improved description of energetic LF from particle-and nucleus-induced reactions; showing a good agreement with a variety of available experimental data. They have an improved predictive power compared to the previous versions and can be used as reliable tools in simulating applications involving such types of reactions.

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Footprint characteristics revised for field‐scale soil moisture monitoring with cosmic‐ray neutrons

Köhli

Schrön

Zréda

et al. 2015

Water Resources Research

248

496

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Cosmic-ray neutron probes are widely used to monitor environmental water content near the surface. The method averages over tens of hectares and is unrivaled in serving representative data for agriculture and hydrological models at the hectometer scale. Recent experiments, however, indicate that the sensor response to environmental heterogeneity is not fully understood. Knowledge of the support volume is a prerequisite for the proper interpretation and validation of hydrogeophysical data. In a previous study, several physical simplifications have been introduced into a neutron transport model in order to derive the characteristics of the cosmic-ray probe's footprint. We utilize a refined source and energy spectrum for cosmic-ray neutrons and simulate their response to a variety of environmental conditions. Results indicate that the method is particularly sensitive to soil moisture in the first tens of meters around the probe, whereas the radial weights are changing dynamically with ambient water. The footprint radius ranges from 130 to 240 m depending on air humidity, soil moisture, and vegetation. The moisture-dependent penetration depth of 15 to 83 cm decreases exponentially with distance to the sensor. However, the footprint circle remains almost isotropic in complex terrain with nearby rivers, roads or hill slopes. Our findings suggest that a dynamically weighted average of point measurements is essential for accurate calibration and validation. The new insights will have important impact on signal interpretation, sensor installation, data interpolation from mobile surveys, and the choice of appropriate resolutions for data assimilation into hydrological models.

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Cascade-exciton model of nuclear reactions

Cited by 263 publications

References 33 publications

Recent Developments in Pre-Equilibrium and De-Excitation Models in Geant4

Recent Developments in Pre-Equilibrium and De-Excitation Models in Geant4

Production of energetic light fragments in extensions of the CEM and LAQGSM event generators of the Monte Carlo transport code MCNP6

Footprint characteristics revised for field‐scale soil moisture monitoring with cosmic‐ray neutrons

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