PSFC / JA - 98 - 25 Performance of Alcator C - Mod Core Thomson Scattering System
نویسندگان
چکیده
Design of the Alcator C-Mod Thomson Scattering (TS) diagnostic is discussed and the results of the measurements are presented. The TS system has 6 spatial channels with observation volumes evenly distributed between the midplane and the edge of the plasma. Each channel is capable of measuring the electron density in the range Ne = 5x 1019 m-3-5x 1021 m-3 and temperature from Te = 200 eV-10 keV. A 30 Hz, 1.5 J per pulse Nd:YAG laser is employed allowing the measurements of evolution of Te and Ne yrofiles during plasma shot. A laser beam position control and feedback system provides for the beam alignment stability and reliable electron density measurements. Examples of the core density and temperature profiles measured at different stages of the plasma evolution are discussed.
منابع مشابه
PSFC/JA-02-6 Observations and Empirical Scalings of the High-Confinement Mode Pedestal on Alcator C-Mod
On the Alcator C-Mod tokamak [Phys. Plasmas 1, 1511, (1994)], radial profiles of electron temperature (Te) and density (ne) are measured at the plasma edge with millimeter resolution Thomson scattering [Rev. Sci. Instrum. 72, 1107 (2001)]. Edge transport barriers in the high confinement regime (Hmode) exhibit Te, ne pedestals with typical widths of 2–6 mm, with the Te pedestal on average slight...
متن کاملPSFC / JA - 99 - 15 Plasma Rotation During Ohmic H - modes in Alcator C - Mod Tokamak
Core plasma rotation is observed to change from the counter-to co-current direction during the transition from low (L) to high (H) confinement mode, in Alcator C-Mod plasmas that are heated purely ohmically. The changes of the toroidal velocities deduced from impurity Doppler measurements and magnetic perturbations associated with "sawteeth" are quantitatively similar. The magnitude of the chan...
متن کاملPSFC/JA-04-33 The Dependence of Core Rotation on Magnetic Configuration and the Relation to the H-mode Power Threwhold in Alcator C-Mod Plasmas with No Momentum Input
The observed toroidal rotation in Alcator C-Mod Ohmic L-mode plasmas has been found to depend strongly on magnetic configuration. For standard discharges with a lower single null and the ion B rB drift downward, and with BT = 5.4 T, IP = 0.8 MA and ne = 1.4 10/m, the core toroidal rotation is measured to be in the range of 1020 km/s (counter-current). Similar plasmas with upper single null have...
متن کاملPSFC / JA - 05 - 46 Advances in measurement and modeling of the high - confinement - mode pedestal on the Alcator C - Mod tokamak
Edge transport barrier (ETB) studies on the Alcator C-Mod tokamak [Phys. Plasmas 1, 1511, (1994)] investigate pedestal scalings and radial transport of plasma and neutrals. Pedestal profiles show trends with plasma operational parameters such as total current IP . A ballooning-like I2 P dependence is seen in the pressure gradient, despite calculated stability to ideal ballooning modes. A simila...
متن کاملThe Measurement of the Intrinsic Impurities of Molybdenum and Carbon in the Alcator C-Mod Tokamak Plasma using Low Resolution Spectroscopy
The intrinsic impurity content of molybdenum and carbon was measured in the Alcator C-Mod Tokamak using low resolution, multilayer mirror (MLM) spectroscopy (∆λ ~ 1-10 Å). Molybdenum was the dominant high-Z impurity and originated from the molybdenum armor tiles covering all of C-Mod's plasma facing surfaces (including the inner column, the poloidal divertor plates, and the ICRF limiter). Despi...
متن کامل