IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Vacuum Science & Technology Monday Sessions
       Session VST-MoM

Invited Paper VST-MoM5
Sealed Vacuum Systems including Vacuum Insulation

Monday, October 29, 2001, 11:00 am, Room 125

Session: Sealed and Insulating Vacuum Systems
Presenter: L. Rosai, SAES Getters’ Group Strategic Marketing Director
Authors: I.P. Della Porta, SAES Getters SPA, Italy
L. Rosai, SAES Getters’ Group Strategic Marketing Director
Correspondent: Click to Email
Vacuum systems can be continuously pumped discharging to air the gasses generated by the process or released by the internal surfaces. However an enormous number of vacuum devices after an initial processing and evacuation are insulated, and sealed-off. The maintenance of a good vacuum for long times requires both a sufficient pumping and efficient baking processes. In most cases an internal chemical pump, a getter, is used to take care of the gasses developed during these processes and the operations of the systems. Getter materials, getter pumps, ion-pumps, cryo-pumps are the most economical and efficient solutions. We will examine the requirements and the solutions of vacuum systems operating in the vacuum better then 1x10@super -10@ torr, typically particle accelerators; of applications where the required vacuum has to be better than 1x10@super -8@ torr, typically certain processes for the semiconductor industry; of devices in which the vacuum or the contaminants partial pressures are in the range of 1x10@super -2@- 1x10@super -8@ torr, typically electron tubes, displays (CRTs,FEDs,etc. ) and lamps. We will examine also sealed off stainless steel devices like dewars or vacuum thermally insulated pipes with vacuum in the range of 1x10@super -6@ - 1x10@super -4@ torr. Finally, we will also consider a new generation of vacuum insulated panels for thermal insulation based on plastic materials where the vacuum is in the range of 1x10@super -3@ to 1 torr. We will illustrate the materials used, the treatments of the surfaces, the various types of tailor made getter materials for each group of vacuum systems. We will also mention the key factors and the mathematical models used to predict the vacuum evolution and the effects of the deterioration of vacuum on the working characteristics of the sealed- off devices.