Electron Swarm Parameters in SF₆and Krypton Gas Mixtures

Abstract

Specific heat and electric susceptibility measurements on praseodymium ethyl sulphate have shown that down to 0.06 K it IS well described by the one-dimensional X Y model with the interaction between nearest neighbour pairs of praseodymium ions arising from electric dipole-dipole coupling. A comparison of the experimental data and the theoretical expression for electric susceptibility gives the nearest neighbour pair interaction parameter, J , equal to k , x 0 7 6 K. The electric dipole moment of the Pr3+ ion was found to be confined to the XYplane and was ofmagnitude y = 7.8 x C m; the consequent electric dipole-dipole interaction parameter between nearest neighbours was k , x 1.12 K, in reasonably good agreement with the J-value determined from electric susceptibility. Both the dipole moment and the low-temperature ordering are interpreted as Jahn-Teller effects. The thermal conductivity shows strong resonant scattering of the acoustic phonons; this is interpreted to be the result of an interaction between the phonons and the elementary excitations of a one-dimensional X Y chain. The resonance energy of k, x (078 & 0.03)K is in excellent agreement with the predicted low-wavevector elementary excitation energy J. The results and interpretation of the various experiments on PrES are compared with the earlier work on praseodymium chloride which showed both one-dimensional and three-dimensional antiferroelectric ordering.

Swarm parameters in SF6and CO2gas mixtures

“…A fitting program was developed on the basis of the present model to obtain swarm parameters from the measured time-resolved current waveform. The apparatus and experimental procedure used here were improved from that described previously [2,3].…”

Gas decomposition and electrode degradation characteristics of a 20% C 3 F 7 CN and 80% CO 2 gas mixture for high voltage accelerators

“…The swarm data of C 3 F 7 CN have also shown that the effective ionisation coefficient increases much slower with increasing electric field than that of SF 6 . The slopes of C 3 F 7 CN and SF 6 gases are 3.53 × 10 −24 and 3.04 × 10 −23 m 2 /Td, respectively [24, 25]. This means that less energy is required for to ionise C 3 F 7 CN than SF 6 .…”

Dielectric characteristic of dichlorodifluoromethane (R12) gas and mixture with N 2 /air as an alternative to SF 6 gas

“…The high GWP of leakage in the atmosphere causes severe harmful effects to the environment. In the past, different researchers tried different binary mixtures containing [6–12]. Trends of emission of from the electrical equipment started from the late 1990s.…”