METALLIC PLATES LENS FOCALIZING A HIGH POWER MICROWAVE BEAM
A metallic grating composed of thin parallel plates opportunely spaced, permits to correct the phase of an incident high power microwave beam. In this work we show how it is possible to obtain a beam focalization (lens), a beam deflection (prism), or a variation in the polarization (polarizer) using parallel metallic plates. The main design parameters are here presented, in order to obtain the wanted phase modification keeping low the diffraction, the reflected power, the ohmic losses and avoiding breakdowns. Following the given criteria, a metallic plate lens has been realized to focalize the 200 KW, 100 msec 60 GHz beam used in the ECRH experiment on the TFR tokamak. The experimental beam concentration followed satisfactory the design requirements. In fact, the maximum intensity increased about twice the value without lens. In correspondence of this distance a reduction of the beam size of about 50% have been measured for the -3 dB radius. The lens supported high power tests without breakdowns or increase of the reflected power.
Bibliographic Reference: WRITE TO CEA MENTIONING REPORT EUR-CEA-FC-1332 EN, 1987
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Record Number: 1989126055800 / Last updated on: 1989-03-01
Available languages: en