X-ray source using carbon-nanotube field emitter with side-gate electrode

A carbon-nanotube (CNT) field emitter with side-gate electrodes, which are placed in-plane with the CNT emitters, is one of the most promising structures to realize a large-area X-ray charge neutralizer with a cost-effective and easy process. An X-ray source using the screen-printed CNT field emitter with side-gate electrodes is developed. The field-emission and X-ray properties are evaluated with anode voltages of 5 and 10 kV. It is shown that the emission current can be controlled by the side-gate voltage even with such high anode voltages as 5 and 10 kV. It is reported that the highest anode current is approximately 1 mu A, which is high enough for an X-ray charge neutralizer. The X-ray radiation is successfully controlled by the pulsed side-gate voltage with subsecond length. (C) 2015 The Japan Society of Applied Physics