Table 1 shows a summary of these values calculated for the cases of 150 MHz and 13.56 MHz. Table 1 Effective resistances and inductances of the Al electrode element[6]   150 MHz 13.56 MHz R (ohm/m) 0.843 0.253 L (H/m) 1.26

× 10−7 1.26 × 10−7 The element width is 0.01 m. Plasma conductance G p and capacitance C p In the case of atmospheric-pressure plasma, since the gap between the electrodes is usually Selleck Salubrinal too narrow (≤1 mm) to perform Langmuir probe analysis, we performed plasma impedance analysis in our previous study [7]. A combination of the measurement of the current and voltage waveforms outside of the apparatus and calculation using the electrically equivalent circuit model enabled us to derive the impedance Z p of the plasma-filled capacitor. Figure 2 shows the measured impedance of atmospheric-pressure helium plasma (real (Figure 2a) and imaginary (Figure 2b) parts of Z p) as a function of applied power density, for 150 MHz and 13.56 MHz excitations using a metal electrode with a diameter of 10 mm and a gap of 1 mm. As shown in Figure 2, the

plasma impedance Z p changes depending on the applied power; this is known as a nonlinear characteristic of the plasma. However, it is also shown that the impedance becomes constant (the system is linear) in a considerably wide power range when sufficiently high power is applied to the plasma. Although taking the nonlinear characteristic of plasma into account will give more exact results, we consider that it is still meaningful to calculate the voltage distribution on the assumption that the plasma impedance 5-Fluoracil clinical trial is constant, since plasma equipment is often used in such a saturated area. Figure 2 Real (a) and imaginary (b) parts of plasma impedance vs. applied power density. Electrode diameter, 1 cm; electrode gap, 1 mm. The plasma conductance G p and the susceptance B p per unit length of element width are calculated from a given plasma impedance Z p

(Z p = R p’ − X p j) using (5) (6) Then the plasma (parallel) capacitance C p per unit Epothilone B (EPO906, Patupilone) length of element width at a particular frequency ω (shown in Figure 3) can be calculated from plasma susceptance B p, as (7) Figure 3 Conversion of plasma impedance (left) to admittance (right). Wavelength and phase velocity in the electrodes The propagation constant γ ≡ α + βj of the solution of Equation 1 is (8) Its real part α (attenuation coefficient) and imaginary part β (phase propagation constant) are described as (9) and (10) The phase velocity v of the electromagnetic wave propagating in the system described by Equation 1 is (11) The wavelength λ is calculated using (12) From these equations, it is clear that the wavelength on the electrode is governed not only by the electrode configuration but also the impedance of plasma. Both the attenuation coefficient α and the wavelength λ greatly affect how a standing wave is formed on the electrode. Results and discussion Equation 1 can be numerically solved by a finite differential method.