Prevakum

Prevakum is a term that can refer to a few different concepts, primarily related to vacuum technology and its applications. In the context of vacuum pumps, a "prevakum" or "pre-vacuum" refers to a preliminary stage of vacuum creation. This typically involves using a roughing pump to lower the pressure within a chamber to a level that a higher vacuum pump, such as a diffusion pump or turbomolecular pump, can then effectively operate at. Without this pre-vacuum stage, the higher vacuum pumps would be unable to function efficiently or at all, as they require a sufficiently low starting pressure.

The process of achieving a prevakum is crucial for many scientific and industrial processes that rely on high vacuum conditions. This includes applications in semiconductor manufacturing, thin-film deposition, mass spectrometry, and particle accelerators. The roughing pump, often a rotary vane pump or scroll pump, reduces the atmospheric pressure in the system to a level typically in the millibar or Pascal range. Once this prevakum is established, the secondary high vacuum pump can be activated to achieve much lower pressures, often in the microbar or even nanobar range.

The term "prevakum" can also sometimes be used more generally to describe any preparatory stage involving the removal of air or other gases before a main process begins. This might be seen in certain types of sealing or packaging operations where an initial evacuation is performed to improve the final seal quality or product preservation. However, its most common and technical usage is within the realm of vacuum system engineering.