Laser-Induced Fluorescence at Lyman-α in the Plasma Edge of TEXTOR-94

✍ Scribed by S. Brezinsek; Ph. Mertens; A. Pospieszczyk

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 578 KB
• Volume: 42
• Category: Article
• ISSN: 0005-8025
• DOI: 10.1002/1521-3986(200211)42:6/7<657::aid-ctpp657>3.0.co;2-6

✦ Synopsis

A new pulsed laser system for laser-induced fluorescence (LIF) measurements on deuterium in front of a graphite test limiter in the plasma edge has been installed on TEXTOR-94. The spectral resolution of the system is about 0.5 pm in the VUV without fine intra-cavity étalon, which is 0.2 pm better than the resolution of the previous system with étalon. Measurements of the line profile of atomic deuterium L α were performed at pulse frequencies of 25 Hz both in the laboratory and in TEXTOR-94. In TEXTOR, velocity distributions of the recycled atoms have been recorded for different radial and poloidal positions. The existence of a large contribution of "slow" atoms with kinetic energies below 1 eV in radial direction (covered range: 0-16 eV) was confirmed [1]. One explanation for the origin of these atoms is their production by dissociation of molecules or of molecular ions from vibrationally excited states [2,3].