Rotation reversal bifurcation and energy confinement saturation in tokamak Ohmic L-mode plasmas

Direction reversals of intrinsic toroidal rotation have been observed in diverted Alcator C-Mod Ohmic L-mode plasmas following electron density ramps. For low density discharges, the core rotation is directed cocurrent, and reverses to countercurrent following an increase in the density above a certain threshold. Such reversals occur together with a decrease in density fluctuations with 2 cm(-1)≤k(θ)≤11 cm(-1) and frequencies above 70 kHz. There is a strong correlation between the reversal density and the density at which the Ohmic L-mode energy confinement changes from the linear to the saturated regime.     

WAVELENGTH DEPENDENCE OF THE QUANTUM YIELD FOR THE STRUCTURAL ISOMERIZATION OF BILIRUBIN

The quantum yield and the relative photochemical yield for lumirubin formation from bilirubin bound to human albumin were determined at eight wavelengths from 410 to 520 nm. The quantum yield averaged 0.0015 for irradiation between 450 and 490 nm. At 410 and 430 nm the quantum yield was slightly lower. At the long wavelength end of the absorption band, from 500 to 520 nm, the quantum yield averaged 0.003. The relative photochemical yield, normalized to constant fluence, was greatest at 500 nm.