ABSTRACT
There have been various methods developed for ion production from nongaseous materials. This chapter discusses these methods, which can be applied to most types of ion sources. Evaporation of pure material gives similar ion yields as with gases if all parts of the ion source are at higher temperatures than the condensation temperature of the entire material. Evaporation is a continuous process and thus best adjusted to dc ion source operation, which is commonly used for ion implantation at lower energies. Materials for the construction of evaporators for ion sources have to meet some general requirements such as: high-temperature stability in vacuum, low vapor pressure, no chemical reaction with other oven or charge material and machinable able or formable to final shape at reasonable cost. To monitor the temperature of an evaporator, one can use direct temperature measurement with thermocouples or resistance thermometers or optical methods with pyrometers or electronic photometers.
