Increase in the Charge State of the Uranium Ion Beam Generated by the MEVVA Ion Source

The Metal Vapor Vacuum Arc (MEVVA) ion source and its modifications are investigated at the Institute of Theoretical and Experimental Physics (ITEP). In a series of the experiments, the possibility of increasing the charge state of the generated uranium ion beam was revealed. The charge state increases as a result of developing a high-current vapor vacuum arc discharge from the source cathode to an auxiliary anode located in an increasing axial magnetic field. The uranium ion beam with a total current of 150 mA was obtained, U⁷⁺ uranium ions being 10% of the current.     

Coal mining in the Russian Donetsk Basin

The activities of coal companies in the Russian Donetsk Basin (Rostov oblast) are considered, as well as the basic coal characteristics, the potential value of local reserves, and the prospects for the region in current economic conditions.     

Improving the technology used to make steel for side members

Conclusions  Statistical methods were used to study the effect of the mass content of different chemical elements on the level of the mechanical properties of normalized universal plates of steel 20GYuT. Multiple correlation equations were obtained and can be used to predict the strength and ductility characteristics of rolled products of steel 20GYuT with a probability of 0.85 in relation to the mass contents of carbon, manganese, and titanium determined from chemical analysis of ladle samples. A study was made of the feasibility of making side-member steel with a mass content of manganese below the level specified by the standard TU14-1-4632-93 (1.0–1.14%). It was established that normalization of heats with a mass content of manganese of 1.0–1.14% produces the specified set of mechanical and service properties as long as the mass content of carbon in the steel is at least 0.19%. To ensure that the required set of mechanical and service properties is obtained, it is recommended that steel 20GYuT be made with a carbon content of 0.19–0.23%, a manganese content of 1.0–1.3%, and a titanium content of 0.10–0.14%. The recommended chemical composition of steel 20GYuT and the heat-treatment regimes that have been developed for rolled plates of this steel will make it possible to do the following:

Crack resistance of chromium-nickel steels with impact loading under cryogenic temperature conditions

Results are presented for an experimental study of the effect of cooling to 77 K on resistance to crack development of chromium-nickel steels 12Kh18N10T and 03Kh20N16AG6 with impact loading. The crack resistance characteristics with a rate of crack growth of 1.5 m/sec were determined from the deformation diagram recorded during testing. Features are noted for crack advance with cooling under conditions of a dynamically applied load.Translated from Problemy Prochnosti, No. 7, pp. 26–29, July, 1992.     

Alloy formation during the sintering of molybdenum-chromium powder mixtures

Conclusions A molybdenum-chromium alloy forms through preferential diffusion of chromium into pure molybdenum, with the formation of a stable molybdenum-base intermediate solid solution, followed, after the disappearance of pure molybdenum, by diffusion of chromium into the intermediate solid solution, resulting in a steady increase in the latter's concentration. The picture of alloy formation in the molybdenum-chromium system differs radically from that in a system exhibiting full intersolubility of components in the solid state, such as the copper-nickel system.Translated from Poroshkovaya Metallurgiya, No. 8(224), pp. 27–32, August, 1981.     

Linear Accelerator for Multiply-Charged Ions at 8 MeV/nucleon – Injector in the TWA Accelerator Complex

The terawatt accumulator at the Institute of Theoretical and Experimental Physics is in the physical startup phase. A new high-current linear accelerator-injector must be developed to achieve design parameters 10¹¹ particles/sec on target; this injector should give at the entrance of the accelerator ring a heavy-ion beam with current 15–20 mA and energy ~7–8 MeV/nucleon with the required charge-to-mass ratio. To this end, a linear accelerator with rf quadrupole focusing at the working frequency 81 MHz was developed; it will accelerate Al¹¹⁺ or Co²⁵⁺ from a laser source before the synchrotron. The accelerator will consist of two sections. The first section with spatially uniform quadrupole focusing will accelerate the beam up to 1.6 MeV/nucleon. A new structure with rf quadrupole focusing and period length 2 is proposed for the second accelerating section. Preliminary numerical simulation of this structure showed that 7 MeV/nucleon with minimum beam losses and accelerating gradients 3.5 MV/m will be achieved on it. Construction of the first section with spatially uniform quadrupole focusing has begun.