Plasma diagnostics refers to the techniques used to measure and analyze the properties of plasma, a state of matter consisting of charged particles. These diagnostics help scientists understand plasma behavior, temperature, density, and composition, which are crucial for applications in fields like fusion energy, space physics, and industrial processes. Common methods of plasma diagnostics include spectroscopy, which analyzes light emitted by plasma, and Langmuir probes, which measure electron density and temperature. By employing these techniques, researchers can gather valuable data to improve plasma confinement in nuclear fusion reactors and enhance the efficiency of various technological applications.