Abstract: The invention relates to vacuum tubes and especially to electron tubes. To produce the tube, and especially an electron collector comprising several electrodes, the electrodes are produced in the form of blocks of ceramic having a high thermal conductivity. The blocks are electrically conducting (at least on the surface). They are preferably made of an insulating ceramic such as aluminium nitride, and are made conductive over part of their surface. The conductive surface part is preferably formed by a conductive ceramic, preferably based on titanium nitride, or on similar conductive ceramic materials. Thus, increased strength, better heat dissipation and weight reduction are achieved.

Abstract: The invention relates to vacuum tubes and especially to electron tubes. To produce the tube, and especially an electron collector comprising several electrodes, the electrodes are produced in the form of blocks of ceramic having a high thermal conductivity. The blocks are electrically conducting (at least on the surface). They are preferably made of an insulating ceramic such as aluminium nitride, and are made conductive over part of their surface. The conductive surface part is preferably formed by a conductive ceramic, preferably based on titanium nitride, or on similar conductive ceramic materials. Thus, increased strength, better heat dissipation and weight reduction are achieved.

Abstract: A method of fabricating an aluminum nitride (AlN) substrate, wherein the substrate is obtained by spraying a powder onto a support at a high temperature and at a high speed, the powder including AlN grains covered with a layer of an oxide precursor chosen from oxide precursors yielding an oxide forming a liquid phase around the AlN grains during spraying.