Ferroelectric Behaviour of Smectic Liquid Crystal

Abstract

The status of modelling work focused on developing the advanced tokamak (AT) scenarios in DIII-D is discussed. The objective of the work is twofold: (a) to develop AT scenarios with ECCD using time dependent transport simulations, coupled with heating and current drive models, consistent with MHD equilibrium and stability; and (b) to use time dependent simulations to help plan experiments and to understand the key physics involved. Time dependent simulations based on transport coefficients derived from experimentally achieved target discharges are used to perform AT scenario modelling. The modelling indicates that off-axis ECCD with approximately 3 MW absorbed power can maintain high performance discharges with qmin > 1 for 5-10 s. The resultant equilibria are calculated to be stable to n = 1 pressure driven modes. The plasma is well into the second stability regime for high-n ballooning modes over a large part of the plasma volume. The role of continuous localized ECCD is studied for stabilizing m/n = 2/1 tearing modes. Progress towards validating current drive and transport models, consistent with experimental results, and developing self-consistent, integrated high performance AT scenarios is discussed.

Frequency response due to the orientational motion of the director around the smectic cone in a surface stabilized ferroelectric liquid crystal

“…The bias voltage was superimposed on a sinusoidal wave of amplitude 1.0 V. Figures 1 (a) and 1 (b) show the equivalent electrical circuits for the FLC. Dynamic hysteresis curves were obtained using the Sawyer-Tower (ST) method [19,20]. The ST circuit shown in figure 1 (c) was constructed with a high precision signal generator (S) (FG200, Yokogawa), a high resolution storage oscilloscope (DL1720, 500 MHz, 1GS/s).…”

Domain mode—A novel relaxation process in ferroelectric liquid crystals

“…Therefore the first order intensity (I) of a diffracted He-Ne laser beam is a measure of the 'modulation depth' of the azimuthal angle (9) in the domain structure (Figures 3a-c).…”

Ferroelectric liquid crystals

“…По мере раскрутки спирали появ-ляется неусредняющаяся величина (Р) = <Р р + P t ) фО, которая наряду Монотонная зависимость <Ymax (Е)) отражает монотонную зависимость (Р (Е) > и, таким образом, свидетельствует о малости флексоэлектрического вклада в величину спон-танной поляризации. Этот результат подтверждается и простой формой петли гистерезиса при измерениях поляризации методом Сойера -Тауэра 4 *> 104 . Прямую оценку величины вклада флексоэлектрического эффекта в спонтанную поляризацию нам удалось сделать 127 в смеси сегнетоэлектри-ческих жидких кристаллов ДОБАМБЦ и ГОБАХПЦ (в которой был реали-зован негеликоидальный жидкий сегнетоэлектрик, п. в) гл.…”