Tatsuya Fukuyama

Deterioration by partial discharges of polyethylene in oxygen containing gas atmosphere

To study the deterioration of LDPE by PD (partial discharge), experiments were conducted using the CIGRE II type electrode in N/sub 2/ (pure nitrogen) and (N/sub 2/+O/sub 2/) gas atmosphere. After being subjected to the PD, specimens were examined by AFM (Atomic Force Microscope). The AFM image clearly revealed the creation of pits on the surface of LDPE specimen. A big difference in the pattern of pits was observed between the specimen subjected to the PD in N/sub 2/ and to the PD in (N2+O2). The FTIR spectra detected in the specimen subjected to the PD in (N/sub 2/+O/sub 2/) showed that carbonyl compounds were produced on the surface of the deteriorated LDPE. The oxidative degradation is presumed to be the dominant process of the deterioration of LDPE by PD in oxygen containing atmosphere.

The influence of additives on the space charge formation and charge profiles in XLPE

Experiments were conducted to measure the space charge profiles in XLPE containing anti-oxidants to examine the origin of heterocharge creation. Negative heterocharge in the vicinity of positive electrode in XLPE containing PDP (Peroxide Decomposition Products) was discoverd to be greatly influenced by the kind of anti-oxidant in XLPE. It is concluded that the synergistic effect between PDP and some kinds of phenolic anti-oxidant is the cause of negative heterocharge creation in XLPE dielectrics. The effect of moisture on the heterocharge creation was also examined.

Experimental Study and Monte Carlo Simulation on Luminous Layers in Neon

The first study on luminous layers phenomena was reported by Hoist and Oosterhuis1 in 1923. They observed the phenomena between a pair of plane parallel electrodes at several V·cm−1Torr−1 and 0.1 µA in a Ne-filled tube. Druyvesteyn2reported on luminous layers phenomena in He, Ne, and Ar. We can recognize the layers which appear at equal intervals between the anode and the cathode by some photographs in the paper. Hayashi3 observed circular luminous layers in a Ne-filled discharge tube with a concentric electrode. Holscher4 investigated the characteristics of the transition from luminous layers to striations in Ne. Emeleus5 discussed the space charge effect in the transitional region from Townsend discharge to glow discharge.