Abstract:
Plasma nanotechnology plays a crucial role in the large-scale synthesis of nanoparticles, which are widely used in various modern technological applications. Conventional microwave-based plasma reactors typically incorporate components such as circula- tor and directional couplers to protect the magnetron from reflected microwave power. However, these components significantly increase the overall system cost and complex- ity. In this study, a cost-effective alternative design for a microwave plasma reactor was proposed and analyzed using finite element simulations. The design replaces the conventional circulator with a three-decibel (3dB) waveguide bridge, which passively redirects reflected microwave energy away from the magnetron, thereby mitigating the risk of damage. During the design process, particular emphasis was given on mini- mizing microwave reflections on the magnetron side. This was achieved by optimiz- ing for a low reflection coefficient and a low Voltage Standing Wave Ratio (VSWR), ensuring minimal power loss and enhanced operational stability. An operational mi- crowave plasm reactor was successfully fabricated using locally sourced and affordable components. The functionality of the system was demonstrated by synthesizing fumed silica nanoparticles, which were subsequently characterized using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS). However, sili- con nanoparticles production from quartz is also possible using the plasma reactor. But due to some complexity this work has been suggested as future prospect for further study and analysis. This alternative reactor design provides a practical and economical solution for microwave plasma generation, eliminating the need for expensive compo- nents while maintaining effective performance. It holds promising potential for a wide range of applications, including nanoparticle synthesis, chemical processing, biomass conversion, and waste treatment.