ELECTRON GUN ARRANGEMENTS

摘要

An electron gun arrangement includes a cathode 1 having a front surface 2 and control grid 3 located in front of it. The control grid 3 is mounted via a cylindrical support 8 on a Kovar mount 12. The cathode 1 is supported by a cylindrical support 6 mounted on a Kovar support 10, Ceramic material 11 being located between the two supports 14 and 12. The vacuum envelope within which the electron gun is contained includes the Kovar support 12 and a flexible member 13 with which it makes a vacuum seal, this member 13 being of copper. The copper member 13 is staled to a ceramic cylinder 16 via metal flanges 17 and 18. The assembly permits the spacing between the cathode and grid 3 to be maintained whilst the copper member 13 permits thermal expansion to occur to maintain vacuum integrity.