[Table of Contents]

Plasma and Fusion Research

Volume 5, S2086 (2010)

Regular Articles

Effect of Collisional Quenching on the Measurement of Ion Species Ratios in Neutral Beam Injectors
Bharathi PUNYAPU and Prahlad VATTIPALLE
Institute for Plasma Research, Bhat, Gandhinagar 382 428, India
(Received 8 December 2009 / Accepted 28 April 2010 / Published 10 December 2010)


In positive ion based Neutral Beam Injectors (NBI), generally corona model is used in analyzing the Doppler shifted spectroscopy diagnostics data for estimating the ion species mix in the ion-source, ion and beam species fractions in extracted beam and power fractions injected into Tokomak. At the beam energies 10-60 keV/amu, the non-radiative processes such as collisional quenching of the excited neutrals affect these estimations when background pressure is ≥ 1 mTorr. We present here a modified corona model that takes into account the effect due to collisional quenching. We describe the application of the present model to a typical Doppler shifted spectral data obtained in SST-1-NBI injector.


neutral beam injection, Doppler shift spectroscopy, corona model, ion species ratio, collisional quenching

DOI: 10.1585/pfr.5.S2086


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This paper may be cited as follows:

Bharathi PUNYAPU and Prahlad VATTIPALLE, Plasma Fusion Res. 5, S2086 (2010).