Field emission behavior of carbon nanotube yarn for micro-resolution X-ray tube cathode.
Carbon nanotube (CNT) has excellent electrical and thermal conductivity and high aspect ratio for X-ray tube cathode. However, CNT field emission cathode has been shown unstable field emission and short life time due to field evaporation by high current density and detachment by electrostatic force. An alternative approach in this direction is the introduction of CNT yarn, which is a one dimensional assembly of individual carbon nanotubes bonded by the Van der Waals force. Because CNT yarn is composed with many CNTs, CNT yarns are expected to increase current density and life time for X-ray tube applications. In this research, CNT yarn was fabricated by spinning of a super-aligned CNT forest and was characterized for application to an X-ray tube cathode. CNT yarn showed a high field emission current density and a long lifetime of over 450 hours. Applying the CNT yarn field emitter to the X-ray tube cathode, it was possible to obtain micro-scale resolution images. The relationship between the field emission properties and the microstructure evolution was investigated and the unraveling effect of the CNT yarn was discussed.
Department of Materials Science and Engineering, KAIST291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Korea.
Jae Won
JW
Hwang
Chan Bin
CB
Mo
Hyun Kyu
HK
Jung
Seongwoo
S
Ryu
Soon Hyung
SH
Hong
D004553:Electric Conductivity; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008422:Materials Testing; D008839:Microelectrodes; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure*; D011856:Radiographic Image Enhancement / Q000295:instrumentation*; D011859:Radiography / Q000295:instrumentation*; D012542:Scattering, Radiation; D013784:Textiles; D014965:X-Rays
D037742:Nanotubes, Carbon