3.
Introduction
3.1.
Titanium Sublimation Pump (TSP)
WARNING:
Do not use unauthorized parts. Such parts may compromise safety. Contact
Gamma Vacuum with any questions.
The TSP is designed to be used in high to extreme vacuum environments,
but it can be operated over a wide range of pressures. TSPs effectively
remove chemically active gases and are excellent in combination with an ion
pump.
The amount of gettering material evolving from an ion pump is directly
proportional to the pressure and atomic weight of the gas molecules.
Therefore, at low pressures there is not sufficient gettering material to
remove light gases (e.g. hydrogen). TSP operation is relatively insensitive to
system pressure and has no difficulty emitting gettering material at low
pressure. In most ultra-high and extreme high vacuum systems, hydrogen is
the primary load contributor. Hydrogen removal is greatly aided with the use
of a TSP.
The TSP is a getter type pump and sublimates titanium from its filaments.
The sublimated titanium coats the line-of-sight surfaces surrounding the
filaments. The titanium serves to capture chemically reactive (non-noble)
gases.
Sublimation requires heating the filaments, which raises the vacuum system
temperature and, temporarily, system pressure. Therefore, the TSP should
be operated intermittently. The film deposited will capture gases
permanently for a long period after firing.
The TSP does not effectively remove all gases (mainly noble) from the
system and therefore should be used in conjunction with other vacuum
pumps (e.g. ion pump).
Due to the conductive nature of the titanium film, it is a good practice to
eliminate line of sight from the TSP to the rest of the vacuum system. If the
film coats electrical insulators (e.g. the ceramic insulators of the sputter-ion
pump) it will create an electrical path that can lead to electrical leakage or
shorts.
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900035_B
900035_B - Introduction
