Rise time

About: Rise time is a research topic. Over the lifetime, 4748 publications have been published within this topic receiving 47512 citations.

Simple sub‐50‐ps rise‐time high voltage generator

Abstract: This article relates to the development of an ultrafast (nanoseconds–picoseconds time scale) compact system(s) readily applicable to the field of EMP/radiation, x‐ray‐induced nondestructive testing, plasma fusion (energy) experiments, bioelectromagnetic (food‐drug) sterilization, drivers for x‐ray preionized XeCl laser and similar applications. The present work shows that the Marx and the Pulse forming section can be integrated into a single unit. The stray capacitance present in each stage acts as a peaking capacitor. For a charging voltage per stage of <40 kV, the rise time of the output pulse is below 50 ps at 200 kV into a 100‐Ω load. Work is in progress to extend the voltage amplitude to 1.6 MV while maintaining the relative pulse waveform. With a contemporary optical diagnostic technique it is believed that the present concept may achieve 1–10 ps rise‐time pulses at a megavolt level in ‘‘smart gas mixtures.’’ In addition a solution for the classical peaking circuit has been obtained and presented in...

Stability of Injection of a Subnanosecond High-Current Electron Beam and Dynamic Effects Within Its Rise Time

Abstract: The stability of the injection of short electron beams and the dynamic processes that occur during their transport were experimentally studied. Beams of energy 200-300 keV, current of 1-1500 A, and duration of 0.05-3 ns with a current rise time of 30-300 ps were formed in a cold-cathode electrode gap. The distribution of the accelerating electric field was highly nonuniform. The cases of vacuum and air insulation of the electron diode were considered. The shortest beams with currents of a few amperes were generated in the mode of continuous acceleration of electrons in atmospheric air. For measuring beam currents, special collector probes were used which ensured a picosecond resolution.

3-d micromagnetic simulation of write field rise time in perpendicular recording

Abstract: A three-dimensional micromagnetic perpendicular recording model has been developed to study the dynamics of perpendicular recording. The write field rise time, shape, and magnitude are investigated. At a data rate of 1 Gb/s, our simulation shows that after 1 ns, the dynamic write field, both the shape and the magnitude, are about the same as compared to the static write field. The magnetostatic field of the medium causes a maximum of 10% write field magnitude decrease in a hard transition. For a flux rise time of 0.2 ns, the head fields follow the reversal flux closely. For a flux rise time of 0.1 ns, both the head field rise time and the average magnetization at the air bearing surface (ABS) increase with decreasing damping constant. The results suggest that increasing the damping constant of both the write head and the medium and decreasing the throat height of the head is important for ultra-high-density recording.

Current and neutron yield scaling of fast high voltage plasma focus

Abstract: Numerical and experimental studies have been made concerning an increase of the effective discharge current for the plasma focus from a bank of constant energy. From the higher discharge current an increased neutron yield is expected. Experimentally an 85 kV/12 kJ device with a current rise time of 600 ns was investigated. The obtained neutron yield was larger by a factor of 3 compared to devices of equal energy but low voltage. The geometrical and pressure variations necessary for optimization, are discussed. Using MHD-calculations and impedance considerations, various banks, including those with high voltage and low inductance, are compared with respect to plasma data and discharge current.