Expansion of the radiographic linear transformer driver (LTD) TO 2.5 MV

Summary form only given. The radiographic linear transformer driver (LTDR) was built as a 1-MV test stand to demonstrate component reliability and the ability to couple LTD cavities to a magnetically insulated transmission line (MITL) and a electron beam diode. The original system consists of seven series cavities and was designed to generate a 100-ns FWHM voltage pulse with peak voltage of 0.8-1 MV and peak current of 125-kA into an electron beam load. The electric field stress in the MITL was too low to generate sufficient electron sheath current to test the impact of MITL electron current on the LTD cavities. We have built an additional 14 LTD cavities which when coupled with the original seven cavities increases the accelerator output to 2.5 MV at a peak current of 125 kA. The upgraded accelerator will be used to investigate the coupling of LTD cavities to a MITL with significant electron power flow and coupling to a radiographic diode.The 21-cavity LTD is assembled in three modules with seven cavities in each module. Each seven cavity module has its own stand to hold the cavities, trigger system, and charge voltage distribution system. The accelerator, including support systems, is about 7-m long and 1.7-m wide. The original seven cavities were built in Tomsk, Russia at the High Current Electronics Institute. The parts for the 14 new cavities were all manufactured in the USA and assembled at Sandia. The silicon-steel cores have been replaced with a cobalt based amorphous alloy METGLASR 2605CO. The multigap spark gap switches have been replaced by a switch developed by L-3 Communications. Comparisons of component performance will be presented.