TheICRF(IonCyclotronRangeFrequency)cleaningtechniquehasbeenusedasaroutinewallcleaningmethodintheHT-7superconductingtokamak.Inawiderangeoftoroidalfield,thcremovalrateofresidualgasbyICRFcleaningwasabouttwentytimeshigherthanthatofglowdischargecleaning(GDC).AtdifferentgaspressureandRFpowerlevels,theICRFcleaningisstudiedcarcfully.Agoodimpurityclcaningeffectandaveryhighhydrogenremovalratewereobtained.Theremovalrateofhydrogenby5kWICRFcleaningachievedwas1.6×10-5Torr.1/s.AndtherelationshipsamongpressureP,outgassingrateQ,atomiclayersLabsorbedonsurfaceandthecleaningmodewerediscussedbriefly.
