RF method for determining the sheath thickness in a plasma

Abstract

PROCEEDINGS LETTERS 1767shown when the 1 A bias current is applied. Above the threshold, the delay time is negligibly small141. When the regions I, 11, 111, and IV are optically pumped by the increased bias current, the small input currents A andB can exceed the threshold easily and optical outputs with quick response can be obtained. This device was designed from the relation between the cavity length, the threshold current density, and the lasing wavelength. The propagation delay of the half adder is the time required for the transition of the lasing modes. A delay time less than 0.4 ns was achieved"]. Using this functional device we were able to constract an ultra-high-speed optoelectronic adder circuit. CW operation of the dual laser at 18°K was observed[61. CW operation was also acheved with the injection laser half adder.

Impedance probe and DC probe studies on the plasma of a glow discharge

“…Different approaches have been made for deriving the RF impedance of the probe sheath, particularly at the floating potential (Mlodnosky and Garriot 1962, Montogomery and Holmes 1964, Crawford and Grard 1966, Smy et a1 1969. According to our previous analysis (Basu and Sen 1967), the probe sheath can be treated as having an impedance R-jX, where and…”

“…The frequency selected for RF measurements was 1 MHz. The RF signal applied to the probe was kept small by adjusting the input to the bridge so that the small-signal approximation (Basu and Sen 1967) could be used in the analysis.…”

“…The RF impedance probe (Mlodnosky and Garriot 1962, Crawford and Mlodnosky 1964, Crawford and Grard 1966, Oliver et a1 1970 and the Langmuir DC probe (Langmuir and Mott-Smith 1924) are well-known tools in plasma diagnostics. An RF impedance method has already been reported by the authors (Basu and Sen 1967) for determining the sheath thickness of a plane probe immersed in a plasma and biased with a DC voltage. It is now extended to give two further important plasma parameters; namely, the electron temperature and the electron density.…”