A heavy impurity (argon) is efficiently pumped out of a two-ion-component tokamak plasma during ICRF experiments in the mode conversion regime. This is achieved by choosing the plasma isotopic composition such that the two-ion hybrid layer location coincides with the position of the cyclotron frequency second harmonic of one of the argon ions. 8-100. R[cm] 102. FIG.l. Radial wave number k L as a function of toroidal co-ordinate R. Toroidal magnetic field B T =51.2 kG, isotopic composition « H / " D = 0.475.
Poly(3-hexylthiophene) thin-film transistors with anodized high-dielectric constant () tantalum pentoxide (Ta 2 O 5 ) and spincoated poly(4-vinylphenol) (PVP) film dual insulator layers were demonstrated. The polymeric PVP layer covering the Ta 2 O 5 can considerably improve the transistor performance. The mobility was increased up to 3:07 Â 10 À2 cm 2 /(VÁs), which is much higher than that obtained by only using a PVP or Ta 2 O 5 single dielectric layer. The threshold voltage of the dual-insulator device was as low as 1.7 V, because the Ta 2 O 5 insulator possesses a high-dielectric constant.