Jinho Choi1,Amar Gupta1,Seung Jun Yeo1,Jaeik Jung2,Moonkyoo Kong3,Jehwang Ryu1
Kyung Hee University1,CAT Beam Tech. Co. Ltd.2,Kyung Hee University Medical Center3
Jinho Choi1,Amar Gupta1,Seung Jun Yeo1,Jaeik Jung2,Moonkyoo Kong3,Jehwang Ryu1
Kyung Hee University1,CAT Beam Tech. Co. Ltd.2,Kyung Hee University Medical Center3
Carbon nanotubes (CNTs) and the methodologies of synthesizing them have attracted researchers from all around the globe because of their unique electrical, mechanical, and optical properties for a wide range of potential applications. In conventional X-ray sources, the tungsten filament is used for producing electrons which are based on a thermionic process and have slow on/off response time. However, using CNTs as an electric field electron emitter, the on/off response time can be as fast as a nano pulse, which makes the perfect digital driving of X-ray sources.<br/>One of the most common synthesis methods to synthesize CNTs is thermal chemical vapor deposition (CVD) using heat to decompose various carbon-based gases. Sufficient work has been done to analyze and optimize the growth characteristics of thermal CVD synthesized CNTs. However, conventional CVD systems are time-consuming due to high temperature operation. The alternative to this kind of slow CVD system could be large-scale inductive heating apparatuses that have been used in metal treatment applications because inductive heating is easy to set up, fast, clean, and inexpensive. In this work, we have used high frequency induction system CVD instead of conventional CVD to synthesize CNTs rapidly on a metal substrate in a compact chamber. Induction heating is a local heating method which can directly heat a conductive material with eddy current generated by an alternating magnetic field based on Faraday's Laws of Electromagnetic Induction.<br/>By induction heating, we have grown CNTs on the metal substrate directly without using external catalysts. Those grown CNTs were characterized by Roman spectroscopy, SEM, and TEM. In a custom built multi field emission chamber, the field emission of CNTs grown at different temperatures was measured. Finally, an electron gun was made using a CNT filed emitter, and X-ray images of IC boards were acquired at 50kV/0.3mA.