Heavy Ion RFQ – Experimental Facility for Reactor Material Investigation under Irradiation
Development of new materials for future energy facilities with higher operating efficiency is a challenging and crucial task. However, full-scale testing of radiation hardness of reactor materials is quite sophisticated and difficult as it requires long session of reactor irradiation; moreover, induced radioactivity considerably complicates further investigation. Ion beam irradiation does not have such a drawback, on the contrary, it has certain advantages. One of them is high speed of defect formation. Therefore, it provides a useful tool for modeling of different radiation damages. Improved understanding of material behaviour under high dose irradiation will probably allow to simulate reactor irradiation close to real conditions and to make an adequate estimation of material radiation hardness. ITEP heavy ion RFQ HIP-1 provides accelerated beams of Cu, Fe, Cr ions with current up to 4 mA and energy 101 keV/n. The results of beam extraction line adjustment for experiments with reactor materials are presented. The construction of controllable heated target is presented as well. The first experiments will be started at the beginning of 2009.Also, the low energy experiments are carried on at the HIP-1 injector. The construction of target for low energy experiments is presented as well. The main objectives of this work are to study primary damage, cascade formation phenomena, phase stability and self-organization under irradiation. This research is carried out by means of tomographic atom probe and transmission electron microscopy.
Effect of irradiation by heavy ions on the nanostructure of perspective materials for nuclear power plants
An imitation experimental technique on the irradiation with heavy ions of structural materials of nuclear power plants using tomographic atom probe analysis has been elaborated. The scheme of irradiation of specimens for atom probe analysis has been realized on a MEVVA ion source of an TIPr accelerator (ITEP) with ion energy 75 keV per charge. Test experiments with irradiation and analysis of samples of the EK-181 steel by aluminum ions to a fluence of ∼2 × 1015 ion/cm2 have been performed. Experiments on the Fe-ion irradiation of the samples of ODS EUROFER perspective steel for fission and fusion reactors to different damaging doses have been carried out. The analysis of distribution of different chemical elements in the volumes tested has revealed that under ion irradiation a change in the composition of nanosized clusters, which are present in the initial material takes place. Comparison of the data obtained with the results of reactor irradiation of the ODS EUROFER steel has been carried out. These data testify a correspondence between nanoscale changes in the steels oxide dispersion strengthened in imitation experiments and under the conditions of reactor irradiation.
Fragment Rotational State Distributions From The Dissociation Of NeIBr: Experimental And Theoretical Results
The IBr fragment rotational state distributions that result when the NeIBr van der Waals molecule undergoes vibrational predissociation have been measured in a pump–probe laser‐induced fluorescence experiment. Independent of initial vibrational state and the number of quanta of vibrational energy lost from the I–Br coordinate, the rotational distributions extend over the full range of energetically accessible states. From the observation of energetic constraints on the rotational distribution, the dissociation energy (D0) is calculated to be 65.5±1.2 cm−1 for the A electronic state, v=16. For the X electronic state, v=0, D0=71.8±1.2 cm−1. Quantum mechanical bound state calculations carried out on a model A electronic state potential energy surface are in quantitative agreement with this result. The rotational distributions are broader than that predicted by either a Franck–Condon or classical impulsive model for the dissociation. The distributions are qualitatively in accord with classical trajectory calc...