2 Kinetic Theory of Gases It is not possible to fully understand the physical processes which occur in the industrial applications of plasma without a knowledge of the behavior of gases on a microscopic scale, i.e. at the level of individual atoms, molecules, and charged particles The behavior of gases on the microscopic scale is described by a branch of physics called the kinetic theory of gases, and the implications of this behavior in the macroscopic world are treated by the subjected of statistical mechanics
It is not possible to fully understand the physical processes which occur in the industrial applications of plasma without a knowledge of the behavior of gases on a microscopic scale, i.e. at the level of individual atoms, molecules, and charged particles. The behavior of gases on the microscopic scale is described by a branch of physics called the kinetic theory of gases, and the implications of this behavior in the macroscopic world are treated by the subjected of statistical mechanics. 2 Kinetic Theory of Gases
2. 1 measurement of high vacuum a In the 19th century when the first quantitative measurements were made in vacuum system, the degree of vacuum was measured with mercury manometers which referred the pressure in the vacuum system to that of the atmosphere. Thus, the common unit of pressure was the millimeter of mercury(mm Hg), in which one standard atmosphere(atm), at 0C, was equal to 760 mm Hg
2.1 measurement of high vacuum n In the 19th century when the first quantitative measurements were made in vacuum system, the degree of vacuum was measured with mercury manometers which referred the pressure in the vacuum system to that of the atmosphere. Thus, the common unit of pressure was the millimeter of mercury (mm Hg), in which one standard atmosphere (atm), at 0℃, was equal to 760 mm Hg
In the mid 20th century An international standards committees decided to change the name of the unit pressure from millimeters of mercury to the Torr, which is, at this time the unit most frequently found in the north america literature of plasma science. The torr was named in honor of evangelista Torricelli (1608-1647), an Italian physical known for his work on barometers
n In the mid 20th century An international standards committees decided to change the name of the unit pressure from millimeters of mercury to the Torr, which is, at this time, the unit most frequently found in the North America literature of plasma science. The torr was named in honor of Evangelista Torricelli (1608-1647), an Italian physical known for his work on barometers
The usual applied situations of the units a Atmosphere: in industrial applications such as thermal plasma processing and magnetohydrodynamic power generation, for these applications, the pressures are usually at or slightly above 1 atm widely used in materials science and Which is a Millitorr or micron : 10-3 Torr or 10-6 torr microelectronic plasma processing, because the used pressures in these applications are usually between 10-3 Torr and 10 Torr
The usual applied situations of the units n Atmosphere: in industrial applications such as thermal plasma processing and magnetohydrodynamic power generation, for these applications, the pressures are usually at or slightly above 1 atm n Millitorr or micron: 10-3 Torr or 10-6 Torr, which is widely used in materials science and microelectronic plasma processing, because the used pressures in these applications are usually between 10-3 Torr and 10 Torr
S/ system a After the introduction of the torr the same nternational standards committee decided that the official unit of pressure in the sI system of units would henceforward be the pascal (symbol Pa), defined as 1 Newton per square meter(N/m2). In the field of industrial plasma engineering, it is still common practice to quote the vacuum pressure in Torr, with an increasing tendency to cite the neutral particle densities, rather than background pressures
SI system n After the introduction of the Torr, the same international standards committee decided that the official unit of pressure in the SI system of units would henceforward be the pascal (symbol Pa), defined as 1 Newton per square meter (N/m2). In the field of industrial plasma engineering, it is still common practice to quote the vacuum pres sure in Torr, with an increasing tendency to cite the neutral particle densities, rather than background pressures