[en] A brief description is given of the procedure used in the global evaluation of the standards and other important cross sections for ENDF/B-VI. The standards involved were ⁶Li(n,t), ¹⁰B(n,α₁), ¹⁹⁷Au(n,γ), and ²³⁵U(n,f). Other standards evaluated independently were H(n,p), ³He(n,p), C(n,f). The other cross sections involved were ²³⁸U(n,γ), ²³⁸U(n,f), and ²³⁹Pu(n,f). The results of the evaluation are compared with new or revised experimental data which have become available after the completion of ENDF/B-VI. Overall good agreement is found, but a few problems are indicated by the new data

[en] This document is intended to provide additional information supplementing a prior publication. The discussion describes the details of the implementation of the proton nonelastic cross section parameterization for LAHET usage. It also documents extensions of the method to stable nuclei with 2 ≤ Z ≤ 5

[en] The mean characteristics of particles in the events with total disintegration of the carbon nuclear target in collisions with π^--mesons (with a momentum of 4.2 A GeV/c) are obtained. The peculiarities of the behaviour of these characteristics depending on the type of event are revealed, and the selection criterion of reactions with the total disintegration of the nuclear target is specified. An indication of the existence of boundary values of the sum charge of detected particles (Q^*) is obtained, after which the regime of the behaviour of the mean characteristics of secondary particles changes depending on Q. It is found that in the events with the total disintegration of the nuclear target, there take place the energy dissipation and the increase of the mean values of the cumulativity orders of secondary particles independent of the mass of the nuclear shell

[en] New experimental data on the behaviour of the single-particle two-dimensional correlation functions R versus Q (Q is the number of nucleons emitted from nuclei) and A_p (A_p is the mass of projectile nuclei) are presented. The interactions of π^--mesons (at a momentum of 40 GeV/c), protons, d, ⁴He and ¹²C nuclei with carbon nuclei (at a momentum of 4.2 A GeV/c) are considered. The values of R are obtained separately for π^--mesons and protons. In so doing, the values of R are normalised so that -1≤R≤1. The value of R=0 corresponds to the case of the absence of correlations. It has been found that the Q- and A_p-dependence of R takes place only for weak correlations (R<0.3). In the main (90%), these correlations are connected with the variable p_t and have a nonlinear character, that is the regions with different characters of the Q-dependence of R are separated: there is a change of regimes in the Q-dependences of R. The boundary values of Q=Q*, corresponding to the transitions from one dependence region to another, are determined. The correlations weaken with increasing A_p, and they become minimum in ¹²CC interactions. Simultaneously with weakening the correlations in the region of large Q≥Q*, the character of the Q-dependence of R changes

[en] Electron form factors and proton scattering data to discrete states in light mass nuclei ( ¹²C and ⁶Li) have been analyzed using fully microscopic theories of the scatterings. Large basis shell model calculations have been used to determine the unique set of one body density matrix elements (OBDME) for electron and proton scattering in both elastic and inelastic channels. When meson exchange current (MEC) corrections are taken into account with the electron form factors and when the proton scattering calculations include all E exchange effects with realistic two nucleon (NN) interactions in the nuclear medium, the electron scattering form factors and the cross sections and analyzing powers from proton scattering (in the energy range 65 to 200 MeV) to discrete states of nuclei can be very well predicted. With credible large basis shell model descriptions of the structure, no a posteriori adjustments to the results of calculations with this approach need be made to reproduce most current data. (authors)

[en] In the search of hybrid system (the coupling of the particle accelerator to an under-critical reactor) for radioactive waste transmutation the TARC (Transmutation by Adiabatic Resonance Crossing) program has been developed. One of the target of the TARC program is the study of the efficiency of a 'Energy Amplifier' system for nuclear waste incineration. Among the radioactive wastes the most interesting is the fission product ⁹⁹Tc from nuclear plants heaving a half-live of ∼ 10⁵ years. Using a fast rabbit technique and gamma ray spectroscopy, the transmutation rate of ⁹⁹Tc by spallation neutrons inside a large lead block was measured. The data from each 9 s rabbit cycle were stocked by means of an acquisition system based on the CERN CASCADE code especially adapted for gamma spectroscopy and able to catch large amounts of coincidence events. The measurements technique is described and the preliminary results are given. Also, in progress are simulations using new technique for production and propagation of neutrons in lead. Due to the plenty of spallation neutrons the capability of burning certain nuclear wastes is already proved

[en] The measurements for ¹⁵⁹Tb(n,2n) ¹⁵⁸Tb reaction by CIAE and Lanzhou University (LNZ) and for ¹⁵⁹Tb(n,γ)¹⁶⁰Tb reaction by CIAE and Peking University (BJG) were used in this work. The evaluation and calculation of the activation cross sections for ¹⁵⁹Tb(n,2n), (n,3n), (n,γ) and some charged particle emission reactions (n,x) below 20 MeV were performed based on experimental and theoretical data so as to meet the nuclear science and technology applications. The present results are compared with the values of averaged theoretical calculation and the experimental data

[en] The nucleon-meson transport code NMTC/JAERI is upgraded to NMTC/JAERI97 which has new features not only in physics model and nuclear data but also in computational procedure. NMTC/JAERI97 implements the following two new physics models: an intranuclear cascade model taking account of the in-medium nuclear effects and the preequilibrium calculation model based on the exciton one. For treating the nucleon transport process more accurately, the nucleon-nucleus cross sections are revised to those derived by the systematics of Pearlstein. Moreover, the level density parameter derived by Ignatyuk is included as a new option for particle evaporation calculation. Other than those physical aspects, a new geometry package based on the Combinatorial Geometry with multi-array system and the importance sampling technique are implemented in the code. Tally function is also employed for obtaining such physical quantities as neutron energy spectra, heat deposition and nuclide yield without editing a history file. The resultant NMTC/JAERI97 is tuned to be executed on the UNIX system. This paper explains about the function, physics models and geometry model adopted in NMTC/JAERI97 and guides how to use the code. (author)

[en] The evaluation of neutron data for ²³⁸Pu is made in the energy region from 10^-5 eV up to 20 MeV. The results of the evaluation are compiled in the ENDF/B-VI format. This work is performed under the Project Agreement CIS-03-95 with the International Science and Technology Center (Moscow). The Financing Party for the Project is Japan. The evaluation was requested by JNDC (JAERI, Japan). (author)

[en] This report summarizes the progress in the work done at the NAC since the first CRP meeting in 1995. According to the agreed work plan excitation functions for medical radioisotopes are done. Experimental cross-section data for the two monitor reactions ²⁷Al (P,x) ²²Na and ^natCu(P,x)⁵⁶Co and for the ¹²⁷I(P,5n) ¹²³X_e reaction employed in the production of ¹²³I as intermediate energies are compiled