New method to define and optimize the diagnostic electrical acquisition channels application to the LMJ DMX plasma diagnostic

The x-ray broadband spectrometer, DMX, is among the first plasma diagnostics to be deployed on Laser Megajoule (LMJ). The emitted x-ray spectrum from laser-produced plasmas is measured in 20 channels from 50 eV up to 20 keV. Each band combines mirrors and filters which realize x-ray band-pass filter and a coaxial diode coupled by a coaxial cable with a fast digitizer that realize the acquisition. The measurement accuracy depends on the equipment performance and the spectrum to acquire. In this context, Commissariat à l´Energie Atomique (CEA) is developing a numerical method called Acquisition Channel Simulator (ACS) whose purpose is to define and optimize all electrical acquisition channels of such diagnostics. The ACS goals are to define numerical model for each element the electrical channel and optimize it. This paper introduces the work led by CEA regarding the development of the ACS method particularly for the equipment model and the first results for the DMX diagnostic.