The present disclosure relates to a high voltage vacuum tube including: a vacuum tube envelope including an interior; an anode assembly disposed within the interior of the vacuum tube envelope; and a cathode assembly disposed within interior of the vacuum tube envelope that emits an electron beam to strike a target surface of the anode assembly and form electromagnetic radiation.

The high voltage vacuum tube includes a braze assembly, the braze assembly including a first component and a second component joined together by a first braze joint, the first braze joint including a composition configured to include a solidification temperature range of no more than 90 C. and a liquidus temperature in the range of 950 C. to 1060 C.; the braze joint including no more than 30.0 wt % in total of one of more precious metals selected from Au, Pd and Pt, relative to the total weight of the first braze joint.