Low pressure microwave plasma UV lamp for water purification and ozone production

Low-pressure mercury lamps are commonly used for germicidal applications. The germicidal effect is due to the emission of light at 254 nm, which leads to the destruction of the most waterborne bacteria and viruses. The Microwave Plasma UV Lamp (MPUVL) is a new technology for generating a high intensity UV light that can be also controlled to produce the Ozone operating wavelength of 185 nm. The microwave power is injected into a resonant cavity and then transferred via a quartz tube wall into the plasma. The MPUVL has many advantages over conventional lamps, which are limited to a maximum output power of 30 W per metre, while MPUVL can deliver any amount of power per unit length and the tube can be of any shape, length, or diameter. This paper describes the design of the MPUVL and compares its efficiency with that of conventional lamps through spectral analysis. Other results, which include the effects of temperature and different power inputs, are also discussed.