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This paper is focused on using plasma as a substitute for metal in a frequency selective surface ('FSS'). FSSs have been used for filtering electromagnetic waves. Each FSS layer has to be modeled using numerical methods, and the layers are stacked in such a way to create the desired filtering. Genetic algorithms are used to determine the stacking needed for the desired filtering. This is a complicated and numerically expensive process. We developed a method to replace metal in an FSS with plasma elements. Our plasma FSSs can be tuned to a desired filtering by varying the density in the plasma elements. This could save much of the routine analysis involved in the standard analysis of the conventional FSS structures. The user simply tunes the plasma to get the desired filtering. Plasma elements offer the possibility of improved shielding along with reconfigurability and stealth. Plasma FSS can be made transparent by turning the plasma OFF. This extends our previous scientific achievements in the development of the plasma antenna. Index Terms--Active antennas, antennas, plasma antennas, plasma devices.

This report is a summary of an extensive research program on plasma antennas. We have found that plasma antennas are just as effective as metal antennas. In addition, they can transmit, receive, and reflect lower frequency signals while being transparent to higher frequency signals. When de-energized, they electrically disappear. Plasma noise does not appear to be a problem. Index Terms--Active antennas, antennas, plasma antennas, plasma devices.

This paper presents a study of one possible form of ball lightning. Plasma spheres several centimeters in diameter were produced in atmospheric pressure air. These spheres persisted for up to a half-second after the power supply was turned off. A mathematical theory was derived that predicts the observed lifetime. The theory predicts that the sphere lifetime should scale as the sphere radius squared, which means that large spheres should persist for many seconds. Index Terms--Arc discharges, ball lightning, lightning, plasma confinement, plasma lifetime, plasma scaling law, plasma spheres.

Van Allen has experimentally observed that the magnetic moments of the planets and stars are proportional to their angular momentum over some 12 orders of magnitude. 'This graph is purely empirical and is regarded with disdain by theorists of planetary magnetism.'--Van Allen. In this paper, I develop a model that both predicts the proportionality between magnetic moment and angular momentum and also fits the experimental results with no adjustable parameters. The model is based on the fact that each rotating planet and star is immersed in a nonrotating conducting plasma cloud, which constitutes a Faraday electrical generator. This Faraday generator is assumed to be the primary source of the magnetic field, in contrast to present models that assume that the flow of magma in the planets' cores is responsible. Index Terms--Astronomy, extra-terrestrial plasmas, geomagnetism, hydrodynamics, magnetic fields, planets.

In multimegavolt electrostatic generators, the accidental sparkover discharges change in character as the voltage and stored energy increase. The usual forked, unidirectional discharges are replaced by complex discharges containing numerous closed loops. It is suggested that this is an example of the formation of closed-current loops that generate magnetic fields in astrophysics.

Proposes a numerical simulation of the temporal evolution of the kinetic energy of positive ions that could be deposited in the plasma source ion implantation process. Description on the numerical model; Results of the simulation; Conclusion.

An adiabatic theory is first presented to show the enhancing effects of a periodic structure and a magnetic field on wave frequency-shifting process by rapidly produced plasma. A device having a cylindrical coaxial line configuration and featuring with a periodic cusp magnetic field is then constructed to study the theoretically predicted time-domain wave phenomena. The magnetic field is introduced by ring-shaped permanent magnets installed outside the outer cylinder of the coax in an arrangement with alternating polarities. A rapid discharge by a rectangular voltage pulse between the center conductor and the outer cylinder of the coax generates periodically distributed plasma inside the coax. As an x-band test wave is introduced to propagate through the line, it is shown that the wave frequency is shifted both upward and downward by suddenly created periodically distributed plasma. The effectiveness of the magnetic field (periodic as well as uniform distribution} on broadening the power spectra of frequency-shifted waves is demonstrated by comparing the spectra for the magnetized cases with that for the unmagnetized case. Index Terms--Electromagnetic propagation in plasma media, periodic structures, plasma devices.

Nonthermal gaseous discharges have been found to be effective agents for biological decontamination/sterilization. The ability to generate these discharges at atmospheric pressure makes the decontamination process practical and inexpensive. In addition, the fact that the plasmas generated by such discharges are cold makes their use suitable for applications where medium preservation is desired. To fully understand the biophysical and biochemical processes induced by the interaction of living cells with gaseous discharges, a multidisciplinary approach is required. In this paper, we present two studies on bacteria killing obtained by two different discharges: a glow discharge at atmospheric pressure and an enhanced corona discharge at atmospheric pressure. Index Terms--Atmospheric pressure, bacteria, corona discharge, decontamination, glow discharge, sterilization.

This paper is an observation of the Aurora Borealis, commonly known as the 'northern lights' in Southern USA. This is only the second time in a century has this rare spectacular event occurred in the observed location. Index Terms--Atmospheric effects, Aurora Borealis, natural phenomena.

Ball lightning has been extensively researched for many centuries. Here, in this paper, we present one form of ball lightning where plasma spheres several centimeters in diameter were produced in atmospheric pressure air. These spheres persisted for up to a half second after the power supply was turned off. A mathematical theory was derived that predicts the observed lifetime. The theory predicts that the sphere lifetime should scale as the sphere radius squared, which means that large spheres should persist for many seconds. Index Terms--Arc discharges, ball lightning, lightning, plasma confinement, plasma lifetime, plasma scaling, spheres.

Steady-state atmospheric pressure nonthermal plasmas can splendidly debilitate bacteria in liquids, gases, and on surfaces, as well as can disintegrate hazardous chemicals. The nonthermal resistive barrier gas discharge at atmospheric pressure is currently investigated for low-temperature sterilization purposes. We have carried out electrical, chemical, optical, and biological studies of the discharge, with the intent of identifying the chemically and biologically active species produced. In this paper, we have demonstrated that effective decontamination can be achieved without causing any damage to the active media.

The problem with fusion reactors today is that they do not produce appreciably more power than they consume to maintain the plasma. However, the problem may now be resolved by considering the entire fusion cycle. Index Terms--Fusion power generation, fusion power generation safety, fusion reactors, plasma applications.

We have developed and tested a steady-state dc plasma discharge apparatus that operates at atmospheric pressure. The important feature is a ceramic discharge electrode that prevents the diffuse discharge from contracting into an arc. The apparatus has been used successfully in the destruction of microorganisms. Index Terms--Gas discharges, glow discharges, plasmas, plasma generation, surface treatment.

Nonequilibrium, atmospheric pressure plasma discharges are increasingly being used in various novel applications. In many of these applications, a nonthermal, large volume, atmospheric pressure discharge, which can be generated in a practical and economical way is sought. Here, we present a novel method to produce such plasma. This method uses a similar configuration to the dielectric barrier discharge. However, instead of a dielectric, a resistive layer is used to cover at least one of the electrodes. This allows the operation of the discharge in either dc or ac (60 Hz) modes. Index Terms--Diffuse, filaments, plasma, resistive, uniform.

Corona discharges in the air are intensified if a small amount of nonelectronegative gas is fed into the limited region around each corona point. The ions produced in the active region then migrate into the air, to produce an intensified negative and positive ion plasma. Index Terms - Corona, glow discharges, plasma applications.

A dust plasma was created using spores in a glass discharge tube. The dust particles become negatively charged, levitate in the positive plasma potential, and behave like massive electrons. A laser beam is used to make the dust visible, revealing plasma structure, such as the wall sheath and the direction of the local electric field.