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The reason of the near-surface layer formation in the Surface Dielectric Barrier Discharge driven by negative voltage pulse has been analysed numerically. According to calculations, the thickness of this layer is around 4μm in atmospheric pressure air; it is inversely proportional to gas density and does not depend on applied voltage value and dielectric parameters. The electric field value inside a layer depends on applied voltage and changes from 60 to 600kV/cm for negative voltage pulse amplitudes from 4.5 to 24kV.

Recovery phenomenon is observed under negative gate voltage stress which is smaller than the previous degradation stress. We focus on the drain current to study the degradation and recovery of negative bias temperature instability (NBTI) with a real-time method. By this method, different recovery phenomena among different size devices are observed. Under negative recovery stress, the drain current gradually recovers for the large size devices and gets into recovery saturation when long recovery time is involved. For small-size devices, a step-like recovery of drain current is observed. The recovery of the drain current is mainly caused by the holes detrapping and tunnelling back to the channel surface which are trapped in oxide. The model of hole detrapping explains the recovery under negative voltage stress reasonably.

The radon indicator is an efficient instrument for measuring the radon daughter concentrations in a house or dwelling. Physics or environmental science students could build a radon indicator as a student project. Another possibility would be to use a radon indicator in a student investigation of radon levels in different houses. Finally the radon indicator is an excellent device for producing a radioactive source, free of charge, for the study of ?-, ?- and ?-radiation. The half-life of the activity collected is approximately 40 min. The radon indicator makes use of an electrostatic method by which charged particles are drawn to a small aluminium plate with a high negative voltage (?5 kV), thus creating a strong electric field between the plate and a surrounding copper wire. The radioactivity on the plate is subsequently measured by a GM-counter and the result calculated in Bq m?3. The collecting time is just 5.5 min and therefore the instrument is only suitable for use in a short-time method for indicating the radon concentration. An improved diagram, ground-radon and/or wall-radon in houses, is presented on the basis of the author's measurements recorded with the radon indicator over many years. This diagram is very useful when discussing how to reduce radiation levels in homes.

A transition from a negative regime to positive streamers in a guiding field has been studied. The apparatus is a simple parallel plane electrode arrangement that provides the uniform guiding field. Negative streamers were generated by a pulsed negative voltage of magnitude ≈5 kV and duration ≈270 ns applied to a trigger pin electrode placed in an aperture at the centre of the grounded electrode and insulated from it by air. It has been shown that the velocities of streamers was between 4×104 and 1.5×105 m s−1 over an external guiding field range of 5.5–6.3 kV cm−1. Results have been presented showing the variation of field in the mid-gap region and the characteristics of streamers. Optical observations have shown the light emission from the developing discharge to be non-linear.

We observed a step formation on Au (111) surface with a scanning tunneling microscope (STM) after the disappearance of the \sscriptsize(22 \atop-1 0 \atop2) reconstruction. Upon exposure to air, the spacing of the reconstructed pattern increased, and finally the pattern disappears. By applying negative voltage pulses to the STM tip, we made depressions of 1–6 atomic layers deep on this surface. Then suddenly a monoatomic step appeared, running almost straight, but detouring around one of the depressions. Since the depth of each depression remained the same as that before the step formation, the step was generated by a dislocation and not by a movement of a top surface layer. The relative position of the step to the detoured depression suggests that the dislocation was created on the surface and then penetrated into the bulk.

We present a theoretical investigation on the transport properties of the nanostructures consisting of magnetic-electric barriers produced by the deposition, on the top of a heterostructure, of metallic ferromagnetic stripe with an applied voltage. Both the transmission probability and the conductance are found to be greatly dependent upon the applied voltage. When a positive voltage is applied to the stripe, both the transmission probability and the conductance shift towards low-energy region and increase. Conversely, they move towards high-energy direction and reduce for an applied negative voltage.

Etching of hydrogenated amorphous carbon (a-C:H) films in 0.1 M nitric acid was evaluated using surface plasmon resonance at the applied voltages of 0.0, −1.0, and 1.0 V. The etching rates of the a-C:H films as functions of the applied voltages and etching duration were obtained to be 0.0368 (at 0.0 V), 0.0117 (at −1.0 V), and 0.0074 nm/min (at 1.0 V). These results clearly indicate that the etching rates decrease significantly under the conditions of applying positive or negative voltage, demonstrating the enhanced corrosion resistance of the a-C:H films upon applying voltage.

In JET disruptions the negative voltage spike appears after the instabilities with which it is usually associated. This unexpected behaviour is explained in terms of an initial trapping of the poloidal flux and its subsequent release, triggered by a sudden cooling of the plasma.

Impulse voltage flashover of a 4 cm point-plane air gap was investigated. The positive-voltage flashover track was found to wander further away from the axis than that for negative voltage. A space-charge model is proposed to explain the difference between these trajectories.

The dynamics of an atmospheric-pressure plasma plume generated in a controlled gas environment are studied. It is found that, at a particular pulse width, two or three plasma bullets are generated in each voltage pulse for both positive and negative voltage pulses. The velocities of the multiple bullets are more than four and less than fourteen times those in the case of a single bullet, for positive and negative voltage pulses, respectively. A detailed analysis shows that the charges carried by the bullets probably play an important role in the propagation of plasma bullets and in the formation of multiple bullets. It is found that the electrode polarity also plays an important role in the generation and propagation of multiple plasma bullets.

We developed light-emitting diodes (LEDs) having a shunt diode in order to improve their negative-voltage electrostatic discharge (ESD) characteristics. To make the discharge path, the n-electrode of the LED was extended over a p-GaN surface. The leakage current at reverse bias owing to the shunt diode can be significantly reduced via plasma treatment on the p-GaN surface prior to the extended n-electrode. In this design, the finger type extended n-electrode was implemented to minimize the light absorption by the n-electrode. The negative-voltage ESD threshold of the LED with the shunt diode significantly increased from 300–500 to 3000 V.

We used the Kelvin probe method to examine the dipole layers induced at the direct-contact HfO2/Si interfaces. Large negative voltage shifts of contact potential difference were observed for the HfO2/Si structures, indicating the existence of strong interface dipole layers (0.8–0.9 V). It was also found that the dipole strength decreased dramatically with ultrahigh vacuum annealing at about 600 °C, at which the interface Si–O bonds are likely to decompose.

A comparison is made between results of the profile control experiments on the JEPP T-II tokamak and those of the time evolution of tearing modes. Over a wide range of conditions, non-linear initial-value tearing-mode calculations are consistent with experimental results. In particular, the time scale of soft disruptions, as reflected in the negative Voltage spikes, given by the tearing-mode analysis, agrees with that obtained experimentally.

Numerical methods have been used to find the electric potential distribution in the stationary ion sheath that initially surrounds wedge-shaped cathodes in a plasma, following the application of a large negative voltage pulse.

An experimental study was made of switching in a metal-nitride-oxide-semiconductor (MNOS) structure with insulator layers formed by plasmochemical deposition on gallium arsenide substrates. Such switching was found to be of threshold nature. The switching by negative voltage pulses occurred only during illumination. The light pulse energy needed for switching was 2×10–6 J/mm2. The charge stored in the traps in the insulator decayed by less than 25% in a period of 20 h after switching.