The disclosed technology includes a mounting enclosure having a replaceable insert panel used to mount an apparatus used in a melting furnace. The replaceable insert panel may be accessed and removed from a rear open end of the mounting enclosure to allow replacement without having to access the interior of the furnace.

An electrical discharge, suitable for heating optical fibers for processing, is made in a controlled partial vacuum, such that saturation of available ionizable gas molecules is reached. The workpiece temperature is thereby made to be a stably controlled function of the absolute air pressure and is insensitive to other conditions. A system and method accomplishing the foregoing are provided.

An electrical discharge, suitable for heating optical fibers for processing, is made in a controlled partial vacuum, such that saturation of available ionizable gas molecules is reached. The workpiece temperature is thereby made to be a stably controlled function of the absolute air pressure and is insensitive to other conditions. A system and method accomplishing the foregoing are provided.

A semiconductor wafer received in a chamber is preheated by light irradiation from halogen lamps, and is thereafter irradiated with flashes of light from flash lamps. Prior to the flash irradiation, ozone is stored in a gas storage tank, so that the pressure in the gas storage tank is higher than atmospheric pressure. On the other hand, the pressure in the chamber is reduced to lower than atmospheric pressure. In this condition, a supply valve is opened between the time when the flash lamps turn on to start the flash irradiation and the time when the temperature of a front surface of the semiconductor wafer reaches a peak temperature. This allows ozone gas to flow all at once from the gas storage tank toward the chamber, thereby supplying the ozone gas instantaneously into the chamber.