In X-Ray sources, a focal spot size produced by an electron beam on a target is directly responsible for quality of the produced image. The commonly produced “small” spots full width at half maximum (FWHM) diameter is around 1.5 mm. Obtaining a submillimeter diameter focal spot in high energy sources (HES), operating at energy of 1-10 MeV is extremely difficult and the difficulty grows with energy value. At Varex, first we obtained a focal spot with FWHM of 0.8 mm, without any additional external focusing devices, which set a record for the standard commercial linacs. Our new design permitted such spot FWHM reduction to less than 0.5 mm and required some changes to the electron beam line and to RF structure, patent pending. Since we tested the first 6 MeV prototypes, we designed a 9 MeV and a 3 MeV linacs using the same technology. We are reporting on progress in designing this new MicroBeam Linatron (MBL) product line.