The influence of temperature on the dielectric strength of gaseous cryogens

The influence of temperature on the dielectric strength of gaseous cryogens has been studied over a wide range of temperature and pressure. Electric breakdown measurements were designed to evaluate if there is any temperature effect after adjusting the pressure to equate the mass density of the gas medium. Breakdown measurements were conducted at 77 K and 293 K with the appropriately selected gas pressure to maintain the equivalent particle number density of helium. A chamber compatible for breakdown experiments at cryogenic temperature was used for the measurements at 77 K. A second chamber was specially designed for breakdown measurements at high-pressure at 293 K. The measurements at both temperatures were conducted over a range of pressures. It was observed that the dielectric strength of the gaseous medium scales with the mass density but no temperature effect was observed. It was also observed that a liner relation exists between the dielectric strength and mass density. These results provide an effective practical method to study the dielectric behavior of gases at a temperature of convenience and use the data to estimate the dielectric properties at a different set of operating temperature and pressure in any application.