Plasma

In the Kazakhstan Material Testing Tokamak (KTM), additional plasma heating will be achieved by injecting power in the ion cyclotron resonance frequency range using four identical generators, each delivering 2 MW of output power. Prior to transitioning the KTM into regular operation, it is necessary to tune these generators using a load equivalent that simulates plasma-like operating conditions. This article presents the electrodynamic design and analysis of a load equivalent capable of absorbing up to 2 MW of high-frequency power. The geometry and key parameters of the load equivalent for the additional high-frequency (HF) plasma heating system of the KTM tokamak are defined. The calculations are based on the assumption that the optimal solution is to construct the load equivalent as a resonator containing a saline aqueous solution absorber housed in a tank with a dielectric window. A dielectric material with high permittivity is proposed for use in the resonator structure. The results demonstrate that the developed load equivalent enables effective testing and tuning of the high-power generators, thus ensuring the readiness of the additional power injection system for scheduled activation on the KTM tokamak. Two plasma load equivalent (PLE) configurations were investigated for different bench-testing purposes. The large PLE was optimized for high RF power absorption in the standing-wave regime, whereas the small PLE was designed to provide a low-impedance loading condition for antenna-matching tests in preparation for plasma operation.

For the first time, results are presented demonstrating the feasibility of carbon dioxide disposal while simultaneously producing syngas using a microwave discharge in liquid methanol, with CO₂ bubbling at atmospheric pressure. The CO₂ input flow rate ranged from 100 to 700 mL/min, and the incident microwave power varied between 450 and 540 W. The main discharge products were H₂ and CO. The highest degree of carbon dioxide decomposition was 75%.

Cold Atmospheric Plasma (CAP) is gaining interest as a biomedical technology due to its ability to modulate cellular behaviour through the controlled delivery of reactive oxygen and nitrogen species (RONS), UV photons, and electric fields. This is particularly relevant to wound healing, where redox modulation can reduce microbial burden and promote tissue repair. Mesenchymal stem/stromal cells (MSCs) are key regulators of immune response and tissue regeneration, suggesting potential synergy between CAP and MSC-based approaches. However, before CAP can be incorporated into MSC-based approaches, it is essential to establish whether it compromises core MSC characteristics. This study investigated the effects of CAP on MSC viability, morphology, phenotype and multilineage differentiation potential. Adipose-derived immortalised MSCs were exposed to CAP using a helium plasma jet under optimised conditions and assessed for up to 72 h. CAP exposure produced treatment-time-dependent effects on metabolic activity and morphology, enabling the identification of a non-cytotoxic treatment window. Under mild conditions, CAP-treated MSCs maintained the characteristic MSC phenotype (CD73-, CD90-, and CD105-positive; HLA-DR- negative) and retained adipogenic, osteogenic, and chondrogenic differentiation capacity. These findings indicate that controlled CAP exposure preserves key MSC properties, supporting further investigation of CAP as a complementary tool for MSC-based wound healing applications.