A compact new incoherent Thomson scattering diagnostic for low-temperature plasma studies

Benjamin Vincent, Sedina Tsikata, Stéphane Mazouffre, Tiberiu Minea and Jérôme Fils
Plasma Sources Sci. Technol. 27, 055002 (2018)

Incoherent Thomson scattering (ITS) has a long history of application for the determination of
electron density and temperature in dense fusion plasmas, and in recent years, has been
increasingly extended to studies in low-temperature plasma environments. In this work, the
design and preliminary implementation of a new, sensitive and uniquely compact ITS platform
known as Thomson scattering experiments for low temperature ion sources are described.
Measurements have been performed on a hollow cathode plasma source, providing access to
electron densities as low as 10^16 m^{−3} and electron temperatures of a few eV and below. This
achievement has been made possible by the implementation of a narrow volume Bragg grating
notch filter for the attenuation of stray light, a feature which guarantees compactness and reduced
transmission losses in comparison to standard ITS platforms.