It is expected that the CW laser propulsion will beone of the propulsion systems used as a orbitaltransfer vehicle because of the potentiality to haverelatively high specific impulse of about 1000 s andthe larger thrust than that of electric propulsionsystems. Our previous study showed that the thermalefficiency decreases with the increase of the specificimpulse due to decrease the pressure.In order to extend operation of the CW laserthruster to the air-breathing configuration in a lowpressure atmosphere such as high altitude, thegeneration technique of inductively coupled plasmas(ICPs) was applied. One of the characteristics ofICPs, which are in contrast to those of LSPs, is thedependency of the minimum power for plasmageneration on the pressure.Estimation has confirmed that the concept wouldeffectively work. And fundamental experimentsshowed that the radio frequency magnetic coupledinductively with LSPs, resulting in the enlargementof the plasma region and the attainment of theenthalpy.In this work the effect of the relative distancebetween the LSP and the coil was investigated. Itwas shown that the increment of the enthalpystrongly depended on the relative position andcoupling of the LSP and RF magnetic field becamestrong as the LSP was located inside of the load coil.
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