| AVS 63rd International Symposium & Exhibition | |
| Vacuum Technology | Tuesday Sessions |
| Session VT-TuM |
| Session: | Vacuum Pumping and Material Outgassing |
| Presenter: | Adrian Wirth, Pfeiffer Vacuum GmbH, Germany |
| Authors: | A. Wirth, Pfeiffer Vacuum GmbH, Germany H. Bernhardt, Pfeiffer Vacuum GmbH, Germany N. Cotton, Pfeiffer Vacuum Inc |
| Correspondent: | Click to Email |
Since its invention in 1958 by Mr. W. Becker, the turbo molecular pump (TMP) has been a milestone in showing new and effective ways of providing oil-free high vacuum. It soon started to replace available pumping principles and as the need for high vacuum grew, it became the standard for modern high vacuum applications. It has since been confronted with increasingly diverse customer needs and performance challenges.
In most aspects, the requirements can be subdivided into primary (pump performance related) properties like pumping speed, gas throughput, compression, fore-vacuum compatibility and secondary ones. The latter including attributes of compactness, ease of system integration, corrosion and condensation insensitivity, usability in areas exposed to ionizing radiation, maintenance friendliness, outgassing and particle cleanliness, emission levels of vibrations, sound or electromagnetic radiation, lifetime and costs of ownership—just to name a few.
From the beginning, demanding applications and processes were on the one hand influencing the vacuum performance of the TMP, hence indirectly affecting the effective shape of the rotor and stator parts and its combination with other pumping principles. On the other hand, triggered by specific and extreme applications or operation settings and surroundings, the secondary requirements gained in importance.
Within this scope, some of today’s applicative challenges and customer needs for TMPs will be presented. Examples will include the operation of TMPs exposed to magnetic fields in ion implanters or ionizing radiation at particle accelerators, in magnetic stray field and vibration sensitive systems such as electron microscopes, integrated into systems in analytics where low sound levels and the ease of integration are of special interest as well as in corrosive processes. Multi-port characteristic applications with rotor designs being specifically tailored for the individual vacuum performance require sophisticated calculation know-how. Apart from these operation purposes, the utilization in tool coating, nuclear fusion experiments, XUV lithography and mobile employments impose particular specifications. Furthermore an overview and comparison of process/requirement specific TMP designs will be provided.
The TMP had and still has to meet most diverse applications and hence undergoes a change from purely vacuum performance driven specification inputs into a period where also secondary requirements are ever since gaining in importance and hence impose a continuous evolution of the TMP technology.