This paper develops a design of high-voltage conversion chain using SiC-MOSFET devices. We have realized a power circuit model which is divided in three parts, a rectifier (AC/DC) then a DC/DC Boost based on SiC-Mosfet and finally a Multistage Marx Generator based on SiC-Mosfet. This structure is intended for high voltage (1.2 KV) and high frequency (100 KHz) applications. In this proposal, a Proportional Integrator Controller is used to control the output voltage of DC/DC Boost converter and to provide a stable voltage for Multistage Marx generator. The originality of this proposal lies in the use of the Multistage Marx generator based on SiC Mosfet devices in the atomic probe tomography applications. We have validated this power circuit model with simulation results on MATLAB and SABER Software.