Simulation of Nonstationary Processes in Pulse Tubular Xenon Lamps in Conditions of Return of Reflected Radiation into Plasma

The study centers around a mathematical model of a pulsed selectively radiating discharge that functions as part of an illumination device and experiences energy interaction with its own wide-range radiation of a complex discrete-continuous structure, the radiation returning to the plasma. We examined some characteristic features of lighting systems with the close spacing of elements that are identified with "optical boilers" (for example, laser pumping systems) characterized by multiple passes of the lamp radiation in the device media and surface network. The study shows that the radiation returned to the plasma and partially absorbed by it leads to an increase in temperature and redistribution of the radiation components from one part of the spectrum to another. This creates the prerequisites for controlling the spectral quality of lamp radiation by means of selectively reflective coatings on the surface of the tube that stabilizes the discharge. As a result, we obtained quantitative data on the ratios of optical density and reflection coefficient providing effective plasma heating by the returned radiation, as applied to powerful xenon radiation sources used for pumping the amplifier cascades of laser fusion synthesis neodymium setups. Findings of the research show that with relatively moderate values of the reflection coefficients on the inner surface of the lamp shells having interference coatings, the radiation efficiency in the pump band of 510...905 nm can be increased by 40...50 %