<title>Improving of flow optical quality in COIL resonator cavity as result of operation of pressure recovery system developed on base of active diffuser</title>

Abstract

Active diffuser-AD has been developed by blowing in the high pressure gas from small scale nozzles along the laser chamber walls. Blowing has stabilized boundary layers, decreased its thickness and prevented its separation. So AD operating has stabilized the gas flow parameters in resonator and localized the zone of slow down of laser flowpseudoshock -after laser chamber. So regular shock -wave structures (X-type shocks) that could degrade the flow optical quality don't appear in resonator.The use of AD allows developing PRS on base of single-stage ejector with high ejection coefficient (usually ground -based COIL PRS consist from passive diffuser and two-stage ejector and has low ejection coefficient).