Tetrahedron Beam Computed Tomography (TBCT) is an innovative x-ray imaging system with improved mobility, speed, image quality and reduced cost. It can be used in image guided intervention as well as a mobile diagnostic CT scanner. Through this project we will develop the key component of TBCT ? the multiple pixel x-ray source. The tube will comprise multiple thermionic cathodes in 10 array with 4 mm spacing. The tube will be sealed, oil cooled and have a total power more than 20 kW. Powered by a biopolar x-ray generator, it will provide sufficient power for clinical TBCT scans. The cooling and collimation systems for this tube will also be prototyped.