Korkeatyhjiö

Korkeatyhjiö refers to a high vacuum environment, a state where the pressure is significantly reduced, bringing it close to the theoretical limit of zero pressure. This condition is achieved by removing as much gas as possible from a sealed volume. The term originates from Finnish, with "korkea" meaning high and "tyhjiö" meaning vacuum. Achieving and maintaining high vacuum is crucial in various scientific and industrial applications due to the unique properties of matter in such environments.

In a high vacuum, the mean free path of gas molecules, which is the average distance a molecule travels before colliding with another, becomes very long. This means that collisions between gas particles are infrequent, and interactions are primarily with the walls of the container or with other surfaces. This characteristic is exploited in applications where contamination from air molecules needs to be minimized or where particle-surface interactions are of primary interest.

High vacuum systems typically employ a series of pumps to progressively reduce pressure. Roughing pumps are used initially to remove the bulk of the air, followed by high-vacuum pumps such as turbomolecular or ion pumps to achieve the desired low pressure levels. Materials used in high vacuum systems must be carefully selected to minimize outgassing, the release of trapped gases from their surfaces, which can hinder the attainment of very low pressures. Common applications include semiconductor manufacturing, where thin films are deposited and etched in vacuum chambers, and scientific research, such as in particle accelerators and electron microscopes.