ABSTRACT
This work is a part of the development of a laser ion source (LIS) for multiply charged ion injectors. This experiment is devoted to the investigation of the effect of a metal grid on the extracted ion characteristics. The energy spectra of the ions in the plasma expanding into a drift tube with and without a grid have been compared. Plasmas of two different target materials, carbon and tungsten, were generated by the CO2 laser pulses with the focal power density on the target of about 1011 W/cm2. The time-of-flight method with an electrostatic energy analyzer installed just behind the grid is used to measure the charge states and energy distributions of ions. A significant effect of the grid on the ion energy distributions has been observed. This effect depends strongly on the ion mass and should be taken into account when designing a LIS, especially in the case of heavy ions.
ABSTRACT
One of the most prospective electrical and optical nonvolatile memory types is the phase change memory based on chalcogenide materials, particularly Ge2Sb2Te5. Introduction of dopants is an effective method for the purposeful change of Ge2Sb2Te5 thin film properties. In this work, we used the ion implantation method for the introduction of In and Sn into Ge2Sb2Te5 thin films by a Multipurpose Test Bench (MTB) at the National Research Center "Kurchatov Institute"-Institute for Theoretical and Experimental Physics. For Sn and In ion implantation into Ge2Sb2Te5, the following MTB elements were used: a vacuum arc ion source, an electrostatic focusing system, and a system for current and beam profile measurements. The MTB parameters for Sn and In ion implantation and its effect on the material properties are presented. Implanted Ge2Sb2Te5 thin films were irradiated by femtosecond laser pulses. It was shown that the ion implantation resulted in a decrease in the threshold laser fluence necessary for crystallization compared to the undoped Ge2Sb2Te5.
ABSTRACT
Metal Vapor Vacuum Arc (MEVVA) ion source (IS) is a unique tool for production of high intensity metal ion beam that can be used for material surface modification. From the other hand, the duoplasmatron ion source provides the high intensity gas ion beams. The MEVVA and duoplasmatron IS developed in Institute for Theoretical and Experimental Physics were used for the reactor steel surface modification experiments. Response of ferritic-martensitic steel specimens on titanium and nitrogen ions implantation and consequent vacuum annealing was investigated. Increase in microhardness of near surface region of irradiated specimens was observed. Local chemical analysis shows atom mixing and redistribution in the implanted layer followed with formation of ultrafine precipitates after annealing.
