06/01402 Measured signatures of low energy, physical sputtering in the line shape of neutral carbon emission: Brooks, N. H. et al. Journal of Nuclear Materials, 2005, 337–339, 227–231

doi:10.1016/s0140-6701(06)81406-2

Abstract

Highlights

Most tokamaks operating with high input powers employ graphite tiles for divertor targets and for first walls
The development of spectroscopic techniques for distinguishing between carbon produced by chemical or by physical sputtering in the DIII-D tokamak has been reported previously [1]
The present work focuses on spectroscopic analysis of C I line shapes in pure helium plasmas, where only

Summary

Introduction

Most tokamaks operating with high input powers employ graphite tiles for divertor targets and for first walls. As a result of plasma-wall interactions, carbon consti-. The development of spectroscopic techniques for distinguishing between carbon produced by chemical or by physical sputtering in the DIII-D tokamak has been reported previously [1]. The present work focuses on spectroscopic analysis of C I line shapes in pure helium plasmas, where only. For near-normal viewing onto a divertor target, asymmetries are anticipated from physical sputtering since most of the carbon atoms move toward the observer, in contrast with the symmetric profiles expected from the nearly isotropic velocity distribution for atoms produced from molecular dissociation.

Apparatus

Theoretical line shapes

Findings

C I profiles due to sputtering by helium