Experimental study of density fluctuations in the STOR-M tokamak by small-angle microwave scattering
Date
2005-12-12
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
Type
Degree Level
Masters
Abstract
Density fluctuations in high temperature fusion plasmas have been a central challenge to the development of fusion power. They are the cause of excessive anomalous losses from the plasma and are still not fully understood. A microwave scattering experiment is performed on the Saskatchewan Torus-Modified (STOR-M) tokamak for the first time to study these density fluctuations with wave-numbers in the range |k| = 5 /cm to 10 /cm. The fluctuations are found to follow k⊥ρₛ scaling consistent with ion drift waves; signatures of the electron temperature gradient (ETG) mode connected with anomalous electron losses are not detected. The fluctuation level in the STOR-M is measured to be ñ/n ≈ 0.1 at a mean perpendicular wave-number of k⊥≈ 7 /cm and is reported for the first time. The fluctuation levels are inversely proportional to the energy confinement time suggesting that these fluctuations are driving anomalous particle and energy losses from the STOR-M. The system is now fully operational and this work paves the way for future experiments with this equipment.
Description
Keywords
Plasma, microwave scattering, density fluctuations, tokamak, ETG mode, ITG mode
Citation
Degree
Master of Science (M.Sc.)
Department
Physics and Engineering Physics
Program
Physics and Engineering Physics