Development of High Energy Transport Code HETC-3STEP Applicable to the Nuclear Reaction with Incident Energies above 20 MeV.

Abstract

Spallation reaction calculation based on the intranuclear-cascade-evaporation model is modified to take into account the pre-equilibrium process by using a closed form exciton model. For the double differential (0, z n ) reaction cross section, the calculation of the exciton model is devised to produce smooth connection of that the cascade process. The result of the exciton model calculation is compared with the neutron energy spectra decomposed from the experimental data by the moving source model analysis. T w o parameters for the transition probability of the excitons and the termination conditions of the pre-equilibrium process are adjusted to reproduce the experimental data. The addition of pre-equilibrium process into the intranuclear-cascadeevaporation model improves the accuracy of the calculation code. The improvement is significant in the backward emission a t incident energy between 20 and 100MeV for target nuclei more massive than aluminum.

CTOF measurements and Monte Carlo analyses of neutron spectra for the backward direction from a lead target irradiated with 200–1000 MeV protons

“…Fig. 21 shows another example of double-differential spectra of complex particles from proton-induced reactions, at higher energies, namely CEM03.01 calculated 4 He spectra at 20, 40, 60, 100, 120, and 140 degrees from 160 MeV p + 27 Al, 59 Co, and 197 Au compared with the Cowley et al data [136]. We see again a good agreement between our calculations and the measurements; the main contribution in the production of these 4 He by CEM03.01 is again from preequilibrium emission.…”

“…To summarize this Section, in comparison with the initial version of the Dubna INC [3,4] 2 Unfortunately, this fact was misunderstood by the authors of the code HETC-3STEP [59]. In spite of the fact that it has been stressed explicitly, and figures with distributions of excited nuclei after the cascade stage of a reaction with respect to the number of excitons and other characteristics were shown in a number of publications (see, e.g., Fig.…”

“…Parts of different versions of the CEM, LAQGSM, or QGSM codes are used in many other standalone codes, like PICA95 [43], PICA3 [44], CASCADO [45], CAMO [46], MCFX [47], ECM [48], and NUCLEUS [49]. Different versions of CEM and LAQGSM, or of the older QGSM, are incorporated wholly, or in part in many transport codes used in a variety of applications, like CASCADE [50], MARS [51], MCNPX [52] GEANT4 [53,54], SHIELD [55], RTS&T [56], SONET [57], CALOR [58], HETC-3STEP [59], CASCADE/INPE [60], HADRON [61], CASCADE-2004 [62], and others.…”

“…[26]), the authors of Ref. [59] misstated this fact as "Gudima et al assumed the state of two particles and one hole at the beginning · · · Hence, their assumption is not valid for the wide range of incident energy", claiming this as a weakness of the CEM and a priority of the code HETC-3STEP, where smooth distributions of excited nuclei after the cascade stage of reactions with respect to n 0 are used. This had already been done in the CEM [1,2].…”

Measurement of Neutron-Production Double-Differential Cross Sections for Intermediate Energy Pion Incident Reaction

“…Calculation codes such as, High Energy Transport Code (HETC), 1) Nuclear Meson Transport Code (NMTC) 2) and NUCLEUS 3) code are based on the intranuclear-cascadeevaporation (INCE) model by Bertini et al 4) These codes have been improved later to be better applicable to the nuclear reactions such as ( p, xn) reactions. 5,6) The validity of the codes has been confirmed by comparison between the computed results and experimental data [7][8][9] for the protonincidence. For the neutron-production cross section by pion incidence, however, there are no experimental data at incident energies around 1 GeV except our test experiment.…”