IEEE Transactions on Plasma Science

The Atomic Weapons Establishment, Aldermaston, U.K., has a number of pulsed-power-driven flash X-ray machines for diagnosing the hydrodynamics of explosively-driven high-atomic-number materials. The most powerful of these machines is Mogul-E, which operates at about 10 MV and 30 kA, delivering about 400 R at 1 m in a 5-mm spot. Longer-term plans envisage the upgrading of existing facilities throug... View full abstract»

Pulse power technology using high intensity (up to 300 kV/cm) nanosecond pulsed electric fields (nsPEF) has been applied for decontamination and amelioration of biofouling, but until now effects on human cells have not been investigated. To analyze structural and functional changes in human cells and solid tumors following exposure to nsPEF, we utilized flow cytometry and immunofluorescence micros... View full abstract»

A laser shearing interferometer (LSI) was used to make spatially and temporally resolved measurements of the electron density profile in an imploding z pinch. Experiments were conducted on the 0.7-MA/250-ns Hawk machine, the 2.5-MA/100-ns ACE-4 machine, and the 3.8-MA/190-ns Double Eagle machine. Time and space resolved measurements of the current and plasma density are needed for better understan... View full abstract»

The paper describes theoretical, numerical, and experimental studies of a decimeter wavelength vircator with electron beam premodulation. Possible mechanisms for the excitation of electromagnetic oscillations in virtual cathode systems are analyzed (modulation of current, reflex klystron effect, and inertial bunching of reflected particles). It is demonstrated that the microwave efficiency in a do... View full abstract»

Application of a fixed high-current breakdown pulse to a high-intensity discharge (HID) lamp causes the voltage to collapse rapidly to a few tens of volts in less than a microsecond. This cold cathode state is characterized by high-current density arc, attachment spots. We have investigated the transition to this state in lamp starting conditions by applying high-voltage pulses to quartz HID arc t... View full abstract»

For the first time, a physics based computational model has been used to provide a direct description of the effects of the traveling wave tube (TWT) on modulated digital signals. The TWT model comprehensively takes into account the effects of frequency dependent AM/AM and AM/PM conversion, gain and phase ripple, drive-induced oscillations, harmonic generation, intermodulation products, and backwa... View full abstract»

The possibility to control functions and membrane transport processes in biological cells by external pulsed electric fields offers new applications for pulsed power technology. One such application is prevention of biofouling, an effect that is based on reversible electroporation of cell membranes. Pulsed electric fields of several kilovolts per centimeter amplitude and submicrosecond duration ha... View full abstract»

This paper will discuss how plasma science issues are addressed by the diagnostics for the National Spherical Torus Experiment (NSTX), the newest large-scale machine in the magnetic confinement fusion (MCF) program. The development of new schemes for plasma confinement involves the interplay of experimental results and theoretical interpretations. A fundamental requirement, for example, is a deter... View full abstract»

The status of experimental research aimed at enhancing the ion charge states in vacuum are plasmas is reviewed. Strong magnetic fields, high-current arc "spikes," and intense electron beams have been used, separately, to increase the metal ion charge states produced. For each method, systematic measurements of ion charge state distributions were made. Each method has its advantages and disadvantag... View full abstract»

Over the past dozen years or so, there have been significant advances in electron accelerators designed specifically for radiography of hydrodynamic experiments. Accelerator technology has evolved to accommodate the radiographers' continuing quest for multiple images in time and space. Improvements in electron beam quality have resulted in smaller radiographic spot sizes for better resolution, whi... View full abstract»

Repetitive pulsed power technology has a lot of potential for growth. After a relatively quiet decade in the 90s, customer interest is increasing. With new interest comes new demands on the technology. Orders of magnitude advances will be needed over the next ten years. This paper speculates where some such improvements may be made. It does not attempt to provide a complete overview of the possibi... View full abstract»