A. I. Ryabchikov

Repetitively pulsed vacuum arc ion and plasma sources and new methods of ion and ion-plasma treatment of materials

Abstract A brief review is presented of the “Raduga 1–5” repetitively pulsed vacuum arc ion sources. Their operating principles and functional ranges are described. The Raduga ion sources provide single- and multi-element implantation. These advantages are achieved by using not only pure single-element or mixed ion beams, but also pulsed beam sequences with controllable composition and energy of each ion species. Another feature of the ion sources is their ability to generate a sequence of ion beam and plasma stream pulses. Switching between ion implantation and plasma deposition can be done from pulse to pulse, within each pulse, or after accumulation of a required dose. “Raduga 5” ion and plasma source operates in a d.c. mode of plasma formation and repetitively pulsed mode of ion beam generation. A new simple and effective system for filtering a plasma flux from the microparticle fraction and the neutral component is described.

Metal vapor vacuum arc ion sources ‘‘Raduga’’

A brief review is presented of the ‘‘Raduga’’ 1–4 repetitively pulsed metal vapor vacuum arc ion sources. Their operation principles and functional ranges are described. The Raduga ion sources provide single‐ and multi‐element implantation. These advantages are achieved by using not only pure single‐element or mixed ion fluxes, but also pulsed beam sequences with controllable composition and energy of each ion species. Another feature of the ion sources is their ability to generate a sequence of ion beam and plasma stream pulses. Switching between ion irradiation and plasma deposition can be done from pulse to pulse, within each pulse, or after accumulation of a required dose. Some specific features of the emission properties of broad beam metal vapor vacuum arc ion sources are described.

Vacuum arc ion and plasma source Raduga 5 for materials treatment

This article describes a new modification of high current ion and plasma source Raduga 5. A dc vacuum arc is used to generate plasma. Generation of accelerated ion beams is realized in the Raduga 5 in a repetitively pulsed mode with the pulse repetition rate up to 200 pps, the pulse duration up to 400 μs and the accelerating voltage up to 50 kV. To clean the vacuum arc plasma from the microparticle fraction of the products of the explosive cathode emission of the arc evaporator a new version of a straight-line plasma filter is used. This article describes a new version of the accelerating diode which works under conditions of high thermal loads with a continuous metal plasma flow and repetitively pulsed formation of an accelerated ion beams. A simultaneous generation of a metal plasma flow and pulse beams of accelerated ions in the Raduga 5 source ensures realization of the technologies of an ion assisted metal plasma deposition, ion implantation under ion sputtering compensation by metal plasma depositio...

Formation of intermetallic layers at high intensity ion implantation

The experimental results are presented on a study of intermetallic phase formation in the surface zone of metal target at high intensity ion implantation. High intensity ion implantation allow to obtain the surface-alloyed layers of a much greater thickness in comparison with ‘ordinary’ ion implantation. Pure polycrystalline nickel was chosen as the target. The nickel samples were irradiated with the aluminum ions using the vacuum-arc ion beam and plasma flow source ‘Raduga-5’. The RBS and TEM were used for the investigations presented. It was established that the fine dispersed intermetallic precipitates are formed in the surface alloyed nickel layer. The alloyed layer thickness is equal to 150 nm and more, while the ion projected range that is equal to 70 nm. Compositions of these intermetallic precipitates are close to Ni3Al and NiAl phases. The solid solution of aluminum in nickel is also formed. The depth dependence of the formation of intermetallic phases can be deduced from the Ni–Al phase diagram.

Dislocation structure in coarse-grained copper after ion implantation

Abstract We have investigated the dislocation structures formed in the near surface region of ion implanted coarse-grained copper (grain size 460 μm) using transmission electron microscopy. Ti and Zr ions were implanted into copper using a vacuum arc ion source. The ion energy was about 100 keV and the applied (incident) dose was 1 × 10 17 cm −2 . We find that Ti and Zr ion implantations produce a developed dislocation structure in the Cu subsurface layers. The dislocation structure changes form cell-net and cell dislocation structures at shallow depth to individual randomly distributed dislocations at greater depth. The maximum dislocation density in copper is 6.1 × 10 9 cm −2 for Ti and 11.4 × 10 9 cm −2 for Zr. The thickness of the modified copper layer with high dislocation density is up to 20 μm for Ti and 50 μm for Zr. Microhardness measurements vs. depth and dopant concentration profiles are presented. The long range effect is explained in terms of a model of static and dynamic mechanical stresses formed in the implanted surface layer.

Very broad vacuum arc ion and plasma sources with extended large area cathodes

Two versions of vacuum arc sources for producing accelerated ion beams and plasma flows are described. The sources are distinguished by use of a dc vacuum arc discharge for plasma generation on the basis of a simple linear or coaxial plasma gun with extended large area (70 300 and 1500 cm2) cathodes and microparticle filtering system. The dc vacuum arc discharge combined with the diode extraction system enables us to use the single source for dc mode of plasma flow formation and repetitively pulsed mode of ion beam generation. Experimental and numerical results are presented on the repetitively pulsed accelerated ion beam formation in the vacuum arc sources with large area cathodes.

Modification of a disordered Ni3Fe alloy surface by 50 keV Zr ion implantation

Abstract It is well known that after ion implantation, microstructural changes are found at depths well beyond the range of the implanted ions. In the present work samples of a disordered Ni3Fe alloy, implanted with four doses of a multicomponent ion beam (where the principal component was zirconium) in the range 0.6–6.0×1017 ions cm−2, have been studied by transmission electron microscopy with subsidiary measurements being made of microhardness and residual stress in some of the samples. It is found that the implanted zone becomes increasingly amorphous and ZrO2 precipitates of increasing size appear as the implanted dose increases. These are accompanied by high internal stresses evidenced by electron micro-diffraction and confirmed by X-ray diffraction measurements. Immediately below the implanted zone, the dislocation density is increased by 2–3 times, depending on the implanted dose, and decreases monotonically down to a depth of about 10 μm. This is accompanied by corresponding increases in microhardness and residual stress which becomes increasingly tensile with the implanted dose.

Behavior of macroparticles near and on a substrate immersed in a vacuum arc plasma at negative high-frequency short-pulsed biasing

It was found that the negative repetitive pulsed biasing of a substrate with respect to the adjacent plasma significantly reduce the macroparticles (MPs) content on surface. The decrease of MPs on the negative potential substrate surface is caused by several different physical mechanisms. Up to 10% of macroparticles can be repulsed from the plasma-substrate voltage drop after being negatively charged in plasma. The MPs surface density on substrate can be significantly reduced after MPs interaction with negatively biased metal surface. This physical mechanism of negatively charged MPs electrostatic repulsion disappears when tungsten grid is used to create a sheath near the substrate surface. Reduction of MPs surface density almost by half takes a place due to ion sputtering. The decrease of MPs surface density by factor of 12 was achieved after the treatment of substrate for 2 min.

Plasma immersion ion charge state and mass spectrometer.

Investigation results of charge state of monocomponent plasma of Ti, Zr, W, and N, as well as that of multicomponent metal plasma of Ti/Zr (50/50 at.%) using plasma-immersion time-of-flight spectrometer are presented in the paper. The case of pressure impact in the working chamber on the ion charge state of combined metal (Ti) and gas-discharge (N) plasma is considered.

High current vacuum-arc ion source for ion implantation and coating deposition technologies

This work is devoted to the development and investigation of a high current ion source based on dc vacuum-arc plasma generation. Extraction and acceleration of ion beams are realized in a repetitively pulsed mode with the pulse repetition rate up to 200 pps, the pulse duration up to 400μs, the accelerating voltage up to 40 kV, and the pulsed ion-beam current up to 2 A. To remove microparticles from the vacuum-arc plasma a straight-line plasma filter is used. Examples of the source use for realization of high-intensity and high-concentration ion implantation regimes including those with formation of doped layers at depths that exceed ion projective range for more than an order of magnitude are presented. At the expense of change in order and intensity of ion and plasma material treatment, the advantage of application of one source for execution of material surface pretreatment and activation regimes, formation of wide transition layers between the substrate and coating, coating deposition, and high-intensi...