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

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.