Norman A. Kent

Norman Albert Kent is an aerial cinematographer and skydiver best known for his aerial videography in films such as Cutaway, Drop Zone and Terminal Velocity. Born in El Paso, Kent grew up in Mexico City, his interest in photography developed as a young teenager after an excursion into the Mexican jungle when he was so taken with the beauty of the experience he wanted a way to share it. When nineteen, Kent made his first parachute jump and found skydiving to be an opportunity to fulfil his passions for both adventure and photography. While still inexperienced Kent had a photograph published as the centrefold of “Parachutist” Magazine which led to offers of commission to shoot for movies and various print media, his first skydiving film was entitled Ride a Cloud, Kent went on to make numerous films targeted at the skydiving fraternity, such as Kinisthesia, Willing to Fly and From Wings came Flight. Kent has been one of the official photographers verifying many skydiving word records in all parts of the globe.

Kent's notoriety for his aerial photography led to a demand for his services in Hollywood and he provided cinematography and coordinated aerial sequences in films such as Cliffhanger, Terminal Velocity and Cutaway. Kent's skydiving expertise and connections in Hollywood have led to skydiving-related stunt work in numerous movies and TV shows; these include: Get Smart Extreme Ops XXX Cutaway Drop Zone Cliffhanger Norman Kent has made over 19,000 skydives during a career spanning over 30 years. Kent was awarded the USPA Gold Medal for Meritorious Achievement in 2006 in recognition of his "contributions to skydiving and the USPA". Kent periodically offers aerial videography workshops. In addition to videography considerations such as lighting and composition, his classes cover camera suits, canopy openings, the special safety considerations unique to videography in freefall. Kent published a book of skydiving photography in 1993 titled Norman Kent Photos. Kent most served as director of photography and stunt coordinator for the skydiving unit for the action comedy Get Smart.

Norman A. Kent on IMDb Norman Kent's website

Surface-wave-sustained discharge

A surface-wave-sustained discharge is a plasma, excited by propagation of electromagnetic surface waves. Surface wave plasma sources can be divided into two groups depending upon whether the plasma generates part of its own waveguide by ionisation or not; the former is called a self-guided plasma. The surface wave mode allows the generation of uniform high-frequency-excited plasmas in volumes whose lateral dimensions extend over several wavelengths of the electromagnetic wave, e.g. for microwaves of 2.45 GHz in vacuum the wavelength amounts to 12.2 cm. For a long time, microwave plasma sources without a magnetic field were not considered suitable for the generation of high density plasmas. Electromagnetic waves cannot propagate in over-dense plasmas; the wave becomes an evanescent wave. Its penetration depth corresponds to the skin depth δ, which can be approximated by δ ≃ c / ω p e 2 − ω 2; the non-vanishing penetration depth of an evanescent wave opens an alternative way of heating a plasma: Instead of traversing the plasma, the conductivity of the plasma enables the wave to propagate along the plasma surface.

The wave energy is transferred to the plasma by an evanescent wave which enters the plasma perpendicular to its surface and decays exponentially with the skin depth.'Transfer mechanism allows to generate over-dense plasmas with electron densities beyond the critical density. Surface-wave-sustained plasmas can be operated in a large variety of recipient geometries; the pressure range accessible for surface-wave-excited plasmas depends on the process gas and the diameter of the recipient. The larger the chamber diameter, the lower the minimal pressure necessary for the SWP mode. Analogously, the maximal pressure where a stable SWP can be operated decreases with increasing diameter; the numerical modelling of SWPs is quite involved. The plasma is created by the electromagnetic wave, but it reflects and guides this same wave. Therefore, a self-consistent description is necessary