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OPERATING CHARACTERISTICS FOR A FIELD EMISSION GUN WITH W[111] TIP |
Yang Deqing; Chen Ergang |
Yunnan University Kunming 650091 |
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Abstract The fabrication method of W[111] tip and the operating characteristics ofa field emission gun (PEG) which consists of W[111] tip, first and second anodes are reported. Experimental results show that on condition that the vacuum in the gun chamber is better than 5×10-7 Pa and acceleration voltage is 30kV, the finite radius of the virtual source of the FEG is 1.6nm, and the brightness of FEG is estimated as 3.8×109 A/cm2, sterad; on condition that the field emission current is 1μA, the stability of beam current is better than 5% in 10 min. It is able to be used in scanning electron microscopesand electron probe system etc.
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Received: 19 March 1991
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