Fabrication of high current carbon nanotube emitters for gyrotron devices

The ring shaped high current carbon nanotube (CNT) cold cathode electron beam was developed for gyrotron application. The various circular ring shaped electron beam designed with CNT emitters for gyrotron was investigated. The circular beam design designed to have CNTs area such as, 0.2 cm 2 ,0.3 cm 2 , 0.5 cm 2 and 0.8 cm 2 . The electron emission current strongly related on the density of CNT emitters and design parameters. The field emission current depend on the ring width and could achieve electron emission current up to 160 mA.