V.I. Kuznetsov

Use of heavy-ion accelerators to produce nuclear membranes

ConclusionAnalysis of the state-of-the-art of the scientific and engineering aspects of the development and application of nuclear membranes shows that rapid progress has been made in the quantitative and qualitative respects. Fields where the use of nuclear membranes is particularly effective have now been determined. Nuclear membranes with pores measuring 0.5–1 μm in size are used extensively for analytical purposes in physicochemical studies and in biological and medical experiments. Membranes with pores of diameter 0.1–0.2 μm are used to make filters for fine purification of technological materials in the fabrication of semiconductor devices. Structures with the smallest pores (<0.1 μm) are used in the technique of thorough gas treatment and in the microbiological industry. The demand for nuclear membranes will rise rapidly. In view of this, it is important to develop and build customized accelerators for the mass production of high-quality filtration material.

Design of the JINR four-meter isochronous cyclotron with smoothly regulated heavy-ion energies

Further development in the physics of nuclear reactions between complex nuclei is bound up with the use of fast ion beams of even heavier elements in these reactions and also with an increase in their energy and intensity. For this purpose, a four-meter isoehronous cyclotron (accelerator U-400) has been designed in the JINR Laboratory of Nuclear Reactions on the basis of the results obtained in the construction of the JINR two-meter isoehronous cyclotron U-200 [1]. At the present time, work at JINR involves the fabrication of parts and sections of the U-400 accelerator, which is being built on the foundations of the existing 310-centimeter, classical heavy-ton cyclotron (accelerator U-300) [2]. The parameters of these accelerators are given in Table 1, from which it is apparent that practically all the systems of the U-400 accelerator differ significantly from those of the U-300. The U-400 cyclotron is vei:y much like the U-200 accelerator, which can be considered as a model of the larger accelerator on