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Study On Electromagnetic Radiation Of High Power Radiofrequency Slab CO2Laser

Posted on:2013-07-19Degree:MasterType:Thesis
Country:ChinaCandidate:B ZhangFull Text:PDF
GTID:2248330392456250Subject:Optical Engineering
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When RF power supply of high power RF excited slab CO2laser works, it also bringsRF electromagnetic radiation because of the leakage of RF electromagnetic wave into the airand forms conductive interference in the power circuit. The electromagnetic radiation ofhigh power RF excited slab CO2laser is systematically researched in this thesis.(1) The space RF electromagnetic radiation and conductive interference was discussedon the basis of analysis of the principle and basic structure of high power RF excited slabCO2laser. TES-92electromagnetic radiation detector was selected to detect electromagneticradiation of slab laser by the method of “simple point measurement” in the area of holes,cracks, etc. Test results implied that the intensity of electromagnetic radiation in near-field inspace was2W/m2, and around holes and cracks was more than99.99W/m2.(2) Shielding and grounding was the most effective method to prevent electromagneticradiation. A copper shell3.8mm thick, could low the space electromagnetic radiation downto0.15W/m2by the way of shielding high power RF power supply. After shielding theperspective window in the laser head with a copper network, electromagnetic radiationintensity was5W/m2. The circuit board of, which was interfered by strong radiation, couldbe protected by an aluminum shell2.8mm thick; the final value of electromagnetic radiationwas0.04W/m2when covered the whole body of RF slab laser with a steel plate5mm thick.(3) Filtering was the best way to suppress conductive interference. The path ofconductive interference included the high voltage power supply circuit, filament-currentsupply circuit, the gate pulse modulated signal drive circuit. The attenuation rejection ratioof55dB,40dB,30dB of LC low-pass filters was designed according to specific parametersof three circuits, using the feed through capacitor, Ni-Zn ferrite and air-wound coil.Eventually, the electromagnetic radiation and conductive interference of high power RFexcited slab CO2laser was effectively resolved by shielding and filtering techniques. It hasan important significance for the industrial engineering of high-power RF slab CO2lasers.
Keywords/Search Tags:Radio frequency excited slab CO2laser, Radio frequency power supply, Electromagnetic radiation, Electromagnetic shielding, Conductive interference, Radio frequency low-pass filter
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