title: Study of laser megajoule calorimeter's thermal behaviour for energy measurement uncertainty optimisation.
abstract: For laser megajoule (LMJ) facility, an accurate procedure for laser pulse energy measurement is a crucial requirement. In this study, the influence of measurement procedure on LMJ calorimeter uncertainty is experimentally and numerically investigated. To this end, a 3D thermal model is developed and two experimental techniques are implemented. The metrological characteristics of both techniques are presented. As a first step, the model is validated by comparing numerical and experimental results. Then, the influence of a large number of parameters considered as likely uncertainty sources on calorimeter response is investigated: wavelength, pulse duration, ambient temperature, laser beam diameter.... The post processing technique procedure is also examined. The paper provides some of the parameters required to allow a robust and efficient calibration procedure to be produced.
authors: CEA, Cesta, BP 2, 33114 Le Barp, France. charles.crespy@yahoo.fr
authors: Charles
authors: C
authors: Crespy
authors: Denis
authors: D
authors: Villate
authors: Olivier
authors: O
authors: Lobios