The IFMIF test facilities design

Calculation of 9Be and 12C thick targets neutron yields from particle accelerator-induced nuclear reactions using PHITS code

The double-differential cross-sections, and neutron yields of the 9Be(4He,n)12C and 12C(d,n)13N reactions at various energies, have been calculated. The cross-sections for the consider nuclear reactions were obtained using PHITS code based on Monte Carlo method. The calculated data were validated against the available experimental data with varying agreement up to 30MeV. We have suggested the most suitable reaction, at certain energies, for better neutron yield and hence radiotherapy applications.

Development of MC-based uncertainty estimation technique of unfolded neutron spectrum by multiple-foil activation method

Unfolding process plays an important role in neutron energy distribution measurement by means of the multiple-foil activation method. We have developed an algorithm for estimating uncertainty of resultant neutron distribution. For the demonstration of the algorithm, we have conducted an experiment to measure thick-target neutron yield (TTNY) of the C(d,n) reaction induced by 20-MeV deuterons with the multiple-foil activation method. The experiment was conducted at Cyclotron and Radioisotope Center, Tohoku University in Japan. The obtained experimental data were analyzed by the algorithm. As a result, we found that uncertainty of derived TTNY has dependency on neutron emission energy. In addition, the dependency is caused by excitation functions of activation reactions. Therefore, we found the particular reactions causing large uncertainty in TTNY. The result of present study shows that the algorithm can evaluate uncertainty and its causes.

Recent progress of a code system DEURACS toward deuteron nuclear data evaluation

Toward deuteron nuclear data evaluation, we have been developing a code system dedicated for deuteron-induced reactions, called DEURACS. In this paper, we review the recent progress in the development of DEURACS. To meet increasing and diversifying demands for deuteron nuclear data, DEURACS has been developed aiming at accurate and comprehensive prediction of deuteron-induced reactions. We present the results of some comparisons between the DEURACS calculations and experimental data for a variety of deuteron-induced reactions at incident energies up to 200 MeV. Double-differential cross sections for emission of neutrons or light ions up to A = 4 and cross sections for production of residual nuclei are analyzed. Neutron yields from deuteron bombardment on thick targets are also analyzed by the Monte Carlo transport simulation based on the deuteron nuclear data provided with DEURACS. Through comparison with experimental and other calculated data, validation of the present modeling in DEURACS is discussed.

Neutron production from thick LiF, C, Si, Ni, Mo, and Ta targets bombarded by 13.4-MeV deuterons

Double-differential thick target neutron yields from LiF, C, Si, Ni, Mo, and Ta targets bombarded by 13.4-MeV deuterons were measured by using an EJ-301 liquid organic scintillator at the Center for Accelerator and Beam Applied Science, Kyushu University. The measured (d, xn) spectra were compared with the (t, xn) spectra measured by the other group at the same incident energy per nucleon (6.7 MeV/u) and theoretical model calculations by Particle and Heavy Ion Transport code System (PHITS) and DEUteron-induced Reaction Analysis Code System (DEURACS). Some bumps are observed in the (d, xn) spectra for low-Z target elements, while no specific structure was seen in the (t, xn) spectra. The PHITS calculation, in which the intra-nuclear cascade of Liége (INCL) and generalized evaporation model (GEM) were used, generally overestimates neutron spectra while the DEURACS calculation agrees with experimental ones fairly well.

The path to fusion power

The promise, status and challenges of developing fusion power are outlined. The key physics and engineering principles are described and recent progress quantified. As the successful demonstration of 16 MW of fusion in 1997 in the Joint European Torus showed, fusion works. The central issue is therefore to make it work reliably and economically on the scale of a power station. We argue that to meet this challenge in 30 years we must follow the aggressive programme known as the 'Fast Track to Fusion'. This programme is described in some detail.