Aging of gaseous detectors is known as the degradation of their
performance under the exposure to ionizing radiation. It is a
complex phenomenon that depends on many parameters. Among
others, aging depends on the gas mixture and may be enhanced by
the presence of pollutants in the gas. The origin of the
impurities is diverse and includes outgassing from assembly
materials and the gas system components, and contamination of
the detector during the assembly process. Systematic studies on
this topic have been carried out. Methods used to ascertain the
outgassing properties of materials are described and
compared. Materials that might be used for assembling gaseous
detectors and associated gas systems are catalogued according
to their outgassing rate. Some factors affecting the aging rate
in some fast gases are presented. Finally, a set of
recommendations to build and operate gaseous detectors in high
luminosity experiments is given.
Abstract: