Characterisation and installation of the Mevex replacement Marx

Summary form only given. Used for flash radiography of explosive experiments, the current suite of 800kV Mevex machines¹ are approaching the end of their operational life due to sub-component obsolescence in their Marx generators. A replacement Marx generator has been designed² in order to ensure continued operations.This paper describes the design and operation of a prototype resistive test load for the replacement Marx. Circuit codes are used to determine the optimal resistive values in order to electrically stress the Marx to 115% of the stress it would experience when charging its ultimate capacitive load. This is then used to predict a reliability of one failure in 10,000. Geometrical design characteristics are also evaluated to ensure no electrical breakdown of the test load and sufficient thermal capacity to deal with the Marx energy.