Time evolution of the process of doping of solids by plasma-ion beams

Irradiation of a solid with intense plasma-ion beams produced within a high vacuumchamber (by the so-called Rod Plasma Injector [1]) is a strongly nonequilibrium process, which enablesachieving a number of effects which are impossible to be achieved with other methods. These are,amongst other: improvement of ceramics wettability, fabrication of stable copper-ceramics interfacesand stable Ni-Cu and Al-Cu interfaces, improvement of tribological properties and high temperatureoxidation resistance of stainless steel, photovoltaic junction formation, and many others. In the paper,the process of plasma-ion beam propagation regarding its time and energy distributions and the processof ion penetration of solids, resulting with ion implementation and temperature growth have beenanalyzed mathematically on basis of experimental data. Results of numerical calculations have beenpresented concerning temperature and dopant density time evolution

Properties of neutron doped multicrystalline silicon for solar cells

The technology of neutron transmutation doping of silicon wafers in MARIA nuclear research reactor is described. The studies of the radiation defects performed with positron annihilation confirmed that divacancies dominate in the irradiated material. Thermal treatment of irradiated silicon at 700-1000°C produces void - phosphorus complexes and void aggregates. The resistivity of the samples produced by neutron transmutation doping was found to be uniform within 2.5% limits. The severe reduction of the minority carrier lifetime in irradiated samples was confirmed

Cyfrowy model procesu elektrodynamicznej akceleracji w urządzeniu typu Coil Gun

The subject of this paper is an analysis of the process of applying kinetic energy to a projectile made from a non-magnetic, electrically conductive material and placed inside of an inductance coil live with alternating current. A digital model of an acceleration system was built, comprising a high-current coil and a cylindrical projectile located inside of the coil. Analytical formulas of the three-dimensional distribution of the axial and radial components of the magnetic field generated by the coil were applied [1]. The mathematical model described herein included the projectile and coil three-dimensional system (with the dimensions and distribution of the coil turns), the parameters of the power supply system and their variations, caused by the energy input to the projectile (and including the variation of: coupling coefficient, pulsation, coefficient of attenuation, inductance, and resistance), and the balance of momentum of the projectile and coil system. A system of equations which depicted the projectile and coil system (the law of electromagnetic induction, the Biot-Savart law, electric-to-kinetic energy transfer, and the balance of momentum of the projectile and coil system) was solved with numerical methods. The conclusions relevant to the design and technology of an ICG (Inductance Coil Gun), derived from the foregoing numerical analysis, were experimentally verified. Initial calculations were completed to optimise the acceleration process. The acceleration efficiency in a cascade of 10 coils was calculated.Przedmiotem pracy jest analiza procesu nadawania energii kinetycznej pociskowi wykonanemu z niemagnetycznego materiału przewodzącego, umieszczonemu wewnątrz cewki, przez którą płynie prąd zmienny. Zbudowano model cyfrowy układu akceleracyjnego złożonego z wysokoprądowej cewki oraz umieszczonego wewnątrz niej metalicznego pocisku w kształcie walca. Wykorzystano analityczne wzory na przestrzenny rozkład składowej osiowej i radialnej pola magnetycznego wytwarzanego przez cewkę [5]. Model matematyczny uwzględnia układ przestrzenny cewka-pocisk (wymiary oraz rozkład zwojów cewki), parametry układu zasilającego z uwzględnieniem ich zmienności w czasie spowodowanej przekazem energii do pocisku, w tym zmienność współczynnika sprzężenia, pulsacji, współczynnika tłumienia, indukcyjności i oporności, a także bilans pędu układu cewka-pocisk. Układ równań opisujący układ (prawo indukcji elektromagnetycznej, prawo Biota-Savarta, przemiana energii elektrycznej w kinetyczną, bilans pędu układu cewka-pocisk) rozwiązano metodami numerycznymi. Dokonano eksperymentalnej weryfikacji płynących z analizy wniosków istotnych z punktu widzenia konstrukcji i technologii urządzenia miotającego typu Inductance Coil Gun (ICG). Wykonano wstępne obliczenia mające na celu optymalizację procesu akceleracji. Przeprowadzono także obliczenia wydajności akceleracji w kaskadzie złożonej z 10 cewek

Badanie procesu akceleracji obiektów makroskopowych w polu magnetycznym cewki indukcyjnej z wykorzystaniem prądów wirowych

The subject of this paper is an analysis of the process of applying kinetic energy to a projectile made of non-magnetic electrically conductive material and located inside an induction coil live with alternating current. An experimental verification was carried out of the analytical conclusions that were pertinent to the design and technology of an inductance coil gun, which is a ranged weapon type.Przedmiotem pracy jest analiza procesu nadawania energii kinetycznej pociskowi wykonanemu z niemagnetycznego materiału przewodzącego, umieszczonemu wewnątrz cewki, przez którą płynie prąd zmienny. Dokonano eksperymentalnej weryfikacji płynących z analizy wniosków istotnych z punktu widzenia konstrukcji i technologii urządzenia miotającego typu Inductance Coil Gun (ICG)

Simulation of the magnetostrictive actuator transients

The paper deals with a magnetostrictive fast-acting actuator applied as a driving device for plasma valve. The actuator is characterized by a relatively small displacement (les then 0.1 mm), but with a very short response time – below 0.1 ms. System is designed for so called “high intensity plasma pulses gun” which is applied in the area of plasma physics and material engineering [1]. A structure with an axisymmetrical actuator energised by discharged pulses of a capacitor has been proposed. The field-circuit mathematical model of the dynamic operation of the actuator has been applied. The model includes: the equation of transient electromagnetic field in a non-linear ferromagnetic material and equation of electric circuit. Using the Borland Delphi 9.0 environment, the computer software has been elaborated. Results of simulation are presented

Enrichment of AISI 316L Steel Surface Layer with Rare Earth Elements Using Ion Beams

Enrichment of AISI 316L steel surface layers with rare earth elements was carried out using two methods with ion beam applying. The first one was the ion implantation with the doses in the range of $1 \times 10^{15} cm^{-2}$ up to $5 \times 10^{17} cm^{-2}$ where mishmetal (Ce+La) was used as the ion source. The second method was the high intensity pulsed plasma beams. The plasma pulses contained both ions/atoms of Ce+La from the electrodes material (mishmetal). The pulse energy densities $(3 J/cm^2)$ were sufficient to melt the near surface layer of the steel and introduce those elements into the surface layer. The aim of this work was to investigate the changes of stainless steel surface properties (morphology, rare earth elements concentration, presence of identified phases) after the rare earth elements addition with or without melting. Scanning electron microscopy, energy dispersion spectroscopy, and X-ray diffraction analysis were used for initial and modified surface characterisation. Grazing-incidence X-ray diffraction shows differences in the identified phase presence in the modified surface layer connected with the modification method

Concept of magneto-hydrodynamic plasma igniter for ignition of low vulnerability gun propellants

Przedmiotem pracy jest koncepcja oraz wstępna weryfikacja eksperymentalna koaksjalnego, plazmowego magnetohydrodynamicznego zapłonnika mało wrażliwych materiałów miotających. Koncepcja jest interesującą alternatywą dla zapłonników, w których plazma wytwarzana jest metodą eksplodującego drutu w generatorach plazmy typu CPG (Capillary Plasma Generator), będących przedmiotem badań wielu laboratoriów na całym świecie.A concept of plasma coaxial magneto-hydrodynamic igniter for low vulnerability gun propellants and initial experimental results are presented in this paper. The concept is an interesting alternative for igniters generating the plasma by a blasting wire such as CPG (Capillary Plasma Generator) systems which have been recently investigated in many worldwide laboratories

Channeling Study of Co and Mn Implanted and Thermally Annealed Wide Band-Gap Semiconducting Compounds

The defect build-up, structure recovery and lattice location of transition metals in ion bombarded and thermally annealed ZnO and GaN single crystals were studied by channeled Rutherford backscattering spectrometry and channeled particle-induced X-ray emission measurements using 1.57 MeV ⁴He ions. Ion implantation to a fluence of 1.2×10¹⁶ ions/cm² was performed using 120 keV Co and 120 keV Mn ions. Thermal annealing was performed at 800°C in argon flow. Damage distributions were determined using the Monte Carlo McChasy simulation code. The simulations of channeled Rutherford backscattering spectra reveal that the ion implantation leads to formation of two types of defect structures in ZnO and GaN such as point and extended defects, such as dislocations. The concentrations of both types of defects are at a comparable level in both structures and for both implanted ions. Differences between both implantations appear after thermal annealing where the Mn-doped ZnO reveals much better transition metals substitution and recovery effect

Structure and Composition of Scales Formed on AISI 316 L Steel Alloyed with Ce/La Using High Intensity Plasma Pulses after Oxidation in 1000°C

It is well documented that the high oxygen affinity elements such as Y, Ce, La, Er and other rare earth elements added to steel in small amounts can improve their high temperature oxidation resistance. Rare earth elements can be either alloyed during the steel making process or introduced through surface treatment techniques. Improvement of high temperature oxidation resistance of AISI 316 L steel by incorporation Ce and La elements into its near surface region using high intensity pulsed plasma beams in so-called deposition by the pulse erosion mode was investigated in the present work. The samples were irradiated with 3 short (μs scale) intense (energy density $3 J//cm^2$) plasma pulses. Heating and cooling processes occur under non-equilibrium conditions. In all samples the near surface layer of the thickness in μm range was melted and simultaneously doped with cerium and lanthanum. The modified samples were oxidized at 1000°C for 100 h in air. The obtained effects were: oxide scales formed on the treated samples were more fine-grained, compact and adhering better that those formed on the un-treated samples

Wettability of carbon and silicon carbide ceramics induced by their surface alloying with Zr and Cu elements using high intensity pulsed plasma beams

Joining of metals with ceramics is very difficult, because properties of these materials are very different. One of the methods of improving mechanical strength of the obtained joints is the introduction of an additional interlayer to the joining area. This paper presents the Zr and Cu-rich layers in C and SiC substrates obtained using the high intensity pulsed plasma beams method. The results of Zr plasma modifications were beneficial and similar to the results obtained in previous works with Ti. The measured contact angles were below 90 centigrade. The results with Cu plasma were unfavourable with contact angles close to 180 centigrade. Apart from the sessile-drop test and to extend the range of analysis, the investigated samples were examined by stereoscopic optical microscopy (OM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDXS), grazing angle X-ray diffraction (GXRD), and Rutherford back scattering (RBS) measurements