– Th? Hello?n s? chuyên nghi?p c?a nhà s?n xu?t trong khâu ti?p th? s?n ph?m.Cold finger-An extended copper rod extending alongside the inside on the electron column. When its reservoir is retained crammed with liquid nitrogen, the rod attracts contaminants That may usually degrade the chamber's vacuum.Nh? s? d?ng công ngh? in ?n Hello?n ??i