Invited lecture on the topic of our innovative sensors with catalytic peaks that operate on the principle of heterogeneous surface recombination of radicals on nanostructured materials with a high coefficient, carried out at the summer school on vacuum electronic and ionic technologies. This is the jubilee 20th meeting, which is one of the largest summer schools specializing in plasma technology. In this lecture the problems of large industrial plasma reactors are presented. In a 2 m reactor suitable for plasma treatment of composite materials, I installed a moving probe and systematically measured the concentration of the radicals. In particular, I was interested in the time stability of the density and the radial dependence of the density of oxygen and hydrogen atoms. I explained the results of time-dependent measurements for unchanged external parameters with the temperature dependence of the recombination coefficient, which is especially important in the case when the treated materials are exposed to hydrogen plasma. In this case, time dependence is often more important than the temporal dependence, which occurs due to the absence of atomic production in the reactor region, where the treated materials are particularly densely distributed. Temporal dependence is more important in the case of oxygen, which is a strong electro-negative gas, so that the formation of negative ions represents an important, sometimes decisive, channel for the loss of free electrons in gas plasma in areas of weak electric field. There is no such phenomenon in hydrogen, which makes hydrogen plasma (and hence the density of radicals) more appropriately distributed in the space between treated materials.
B.04 Guest lecture
COBISS.SI-ID: 30817831Personally, I was the chair of the organisation committee of this workshop organised in Slovenia, where approximately 40 invited speakers were present, which we have chosen primarily among the leaders in the world of leading scientific groups dealing with the topic of plasma treatment of surfaces of modern materials and the related characterisation of gas plasma. The organisation of the workshop was very important for acquiring the knowledge needed to expand the range of our sensor's work in the field of low density of atoms. For the treatment of biological materials, of course, plasma with a low radical density is required, otherwise these samples can be destroyed due to temperature effects. At the workshop I was specifically talking about the possibilities of carrying out measurements in foreign laboratories, which have alternative techniques.
B.01 Organiser of a scientific meeting
COBISS.SI-ID: 289288960Personally, I was the chair of the organisation committee of the Cambodia conference, where we had about 50 invited speakers, selected primarily among the leaders in the world of leading scientific groups dealing with the topic of plasma treatment of surfaces of modern materials and the related characterisation of gas plasma. The organization of this meeting gave me an in-depth discussion with competent participants and at the same time recognising our theme and the way of promoting our scientific and technological achievements.
B.01 Organiser of a scientific meeting
COBISS.SI-ID: 4158287The Asian European International Plasma Surface Engineering Conference is the largest scientific conference in East Asia, specialised in tailoring the surface properties of materials with thermodynamically imbalanced gas plasma. In the invited lecture entitled "Neutral reactive gas species and reactors suitable for plasma surface engineering", about 500 participants of the conference listened about the importance of neutral radicals for tailoring the surface properties of treated materials. I have especially highlighted the problem of plasma inhomogeneity, and in particular the inhomogeneity of the density of reactive plasma particles due to the presence of treated materials in plasma reactors. These are the results of the measurements carried out in different reactors and different processing parameters. In all cases, our laser-controlled sensors with a nanostructured catalytic tip were used to measure the density of the atoms, which is especially useful in cases of large gradients when the density changes for three orders of magnitutde, which is not measurable with any other technique.
B.04 Guest lecture
COBISS.SI-ID: 30825767