Error analysis in the spectroscopic measurement by Doppler shift spectroscopy system for negative ion based neutral beam injection system

A negative ion source based neutral beam Indian test facility, INTF consists of a 100 keV H-RF source, under developmental stage at Institute for Plasma Research (IPR). The test facility is to validate the performance of Diagnostic Neutral Beam to be delivered to ITER. A large set of diagnostics are planned to be deployed in the INTF to measure and optimize the beam performance of the 100 keV H- beam. Doppler Shift Spectroscopy (DSS) diagnostics is under conceptual stage to estimate the beam divergence and stripping losses of the beam with an error less than 10% of the designed value (∼10 mrad). In this paper, we present the results of the divergence analysis and the conceptual design of the DSS system based on these calculations