Course detail

# Vacuum Technology

Gas, vapour, pressure, Kinetic theory of gases. Volume processes and transport of gas, gas diffusion and gas viscosity. The gas transport through the vacuum pipes. The surface processes, adsorption, desorption. The pumping processes, The basic principles of the gas transport. Transport and getter pumps. Pressure measurement. Thermocouple Gauges, Pirani Gauges. Ion Gauges. The basic principles of vacuum equipment design. Technological processes in low pressure gases.
Devices based on trajectory of charged particles. Devices based on gas discharge. Electronics in electro-vacuum instrumentation.
Devices based on gas volume and gas particle properties.
Devices based on cryogenic technology.

Learning outcomes of the course unit

Based on the verification of the student's knowledge and skills in seminars, laboratory work and in the written exam, after completing the course the student is able to:

Interpret the ideal gas laws: Boyle-Mariott, Gay-Lussac (Charles´s) and Dalton laws.
Derive and interpret the Equation of state of ideal gas.
Derive from the Equation of state numerical value of the Universal Gas Constant, Avogadro's Number and Boltzmann constant.
Derive from the Equation of state the relation between pressure, gas concentration and the temperature.
Define conditions for modeling the processes in gases using the Kinetic theory of gases.
Calculate the number of incident molecules per unit time per unit area.
Calculate the mean free path of particles in the gas and discuss its impact on the processes in vacuum.
Define and explain the Maxwell-Boltzmann velocity distribution of particles in the gas.
Calculate the mean velocity, root mean square velocity and most probable velocity of particles in a gas.
Describe and discuss the volume and transport phenomena in gas - particle diffusion, viscosity and thermal conductivity of gas.
Describe and discuss surface processes in vacuum.
Define and explain the basic adsorption isotherms - Langmuir, Henry and BET isotherms.
Define saturated vapor pressure and discuss the processes associated with the saturated vapor pressure.
Define vacuum resistance and conductivity of the vacuum pipe.
Define respective gas flow mechanisms for different types of gas flow.
Calculate and measure the conductivity of a vacuum pipe for different types of the gas flow.
Define nominal and effective pumping speed of the vacuum pump.
Define the equation of continuity and interpret its meaning for pumping of vacuum equipments.
Describe the processes and mechanisms that are used for pumping of vacuum devices.
Describe and discuss the influence of vacuum leaks and desorption processes.
Calculate the ultimate pressure of vacuum equipment.
Calculate the required pumping speed pumps with regard to the arrangement of the apparatus.
Calculate the time of exhaustion to the desired pressure.
Measure the pumping speed of the pump using a constant pressure and constant volume methods.
Describe and explain the operation of transport pumps.
Describe and explain the operation of sorption pumps.
Define and explain methods for measuring the vacuum-pressure.
Describe and explain the operation of thermal vacuum gauges.
Describe and explain the operation of Penning ionization vacuum gauge and triode vacuum gauge.
Design and build a simple vacuum apparatus.
Describe and discuss the design of high voltage power sources for vacuum technology.
Describe and discuss the design of radio-frequency generators for vacuum technology.
Describe and explain the methods of measurement of very low current for electro-vacuum equipments.
Describe and explain the methods of potential insulation for electro-vacuum equipments.
Describe and discuss electronic protection circuits for electro-vacuum equipments.
Describe and explain operation of mass flow-meters.
Define and explain electromagnetic and electrostatic deflection.
Describe and explain operation of mass spectrometers.
Describe and explain operation electron microscopes.
Define superconductivity.
Give and explain examples of exploitation of superconductivity.
Describe and explain methods of thermal insulation.
Describe and discuss the operation of cryopumps.
Define the types of discharges and give examples of their exploitation.
Define plasma parameters and explain the measurement of plasma parameters.
Describe and discuss the technology of cathode sputtering.
Describe and discuss the technology of plasma deposition from gas phase.
Define the technology of dry etching and give examples of its use.

Prerequisites

The subject knowledge on the Bachelor´s degree level is requested.

Co-requisites

Not applicable.

Recommended optional programme components

Not applicable.

Fikes L. :Fyzika nízkých tlaků ,SNTL, Praha 1991 (CS)
Pátý L. : Vakuová technika ,ČVUT, Praha 1990 (CS)
Grozskowski J. :Technika vysokého vakua ,SNTL, Praha 1981 (CS)
Boušek J., Kosina P.: Vakuová technika MVAF, FEKT VUT V BRNĚ, elektronické skriptum

Planned learning activities and teaching methods

Teachning methods include mutually interlaced lectures, numerical exercises and practical laboratories. Course is taking advantage of e-learning (Moodle) system. Each student elaborates an individual project.

Assesment methods and criteria linked to learning outcomes

Laboratory practicum - 30 points; minimum 20 points.
Learnuing activity 10 points.
Final exam – 60 points; minimum 30 points.

Language of instruction

Czech

Work placements

Not applicable.

Course curriculum

Gas, vapour, pressure, Measurement units and their relation.
Basic principles and laws for the ideal gases. Boyle-Mariott law, Gay-Lussac law. The state equation of the gas. Dalton law. Important constants.
Kinetic theory of gases - basic principles. Relation
between pressure, concentration and temperature of gas. The mean free path of gas molecules. The thermal velocity
of the gas molecules, Maxwel-Boltzmann statistic.
Volume processes and transport of gas, diffusion, viscosity of gas, thermal conductivity of gas.
The gas transport through the vacuum pipes. Gas conductance of Vacuum pipes. Ohms law in gas transport. The volume and mass flow of the gas. The different mechanism of the gas transport - turbulent, viscose, molecular, effusion.
The limit pressure of the vacuum equipment. Pumping speed of the vacuum pumps and its measurement, the exhaust time. The influence of leakage and desorption.
The surface processes, adsorption, desorption, monomolecular and multimolecular layers, basic adsorption isotherms, saturated vapour pressure.
The basic principles of the gas transport, Transport and getter pumps. The pumping processes
Mechanical pumps, Two Stage Mechanical pump, Roots blowers, Turbo pumps, Diffusion pumps. Oil mist eliminators,
Getter pumps, Ion pumps, Diode Ion pumps, Titanium sublimation pumps, diode and triode Ion pumps. Cryopumps. Sorption pumps, Molecular sieve .
Pressure measurement (absolute and relative), Torricelli tube, U- tube, Thermocouple Gauges, Pirani Gauges.
Ion Gauges, Cold Cathode Gauges , Alfatron , Penning Gauges. Design of the triode Ion Gauge. Alpert-Bayard and Helmer-Hayward tube design.
The basic principles of vacuum equipment design. Technological processes in low pressure gases.
Electronic circuits for electro-vacuum instrumentation. High voltage power sources. High frequency generators. Circuits for measurement of very low current. Circuits for the potential isolation. Electronic protection circuits.
Devices based on gas volume and gas particle properties. Vacuum gauges. Mass flow-meters.
Devices based on trajectory of charged particles. Electromagnetic and electrostatic deflection. Mass spectrometers. Electron microscopes.
Devices based on cryogenic technology. Superconductivity, exploitation of superconductivity. Methods of thermal insulation. Cryopumps.
Devices based on gas discharge. Types of discharges, examples of their exploitation. Plasma parameters, measurement of plasma parameters. Cathode sputtering. Plasma deposition from gas phase. Dry etching.

Aims

Acquirement of the knowledges about modern vacuum technics for use in electronics, in electrotechnical and mechanical industry

Specification of controlled education, way of implementation and compensation for absences

Laboratory practicum. Numerical practicum.

Classification of course in study plans

• Programme EEKR-ML1 Master's

branch ML1-MEL , 1. year of study, winter semester, 4 credits, optional specialized

• Programme EEKR-CZV lifelong learning

branch ET-CZV , 1. year of study, winter semester, 4 credits, optional specialized

#### Type of course unit

Lecture

13 hours, optionally

Teacher / Lecturer

Fundamentals seminar

12 hours, compulsory

Teacher / Lecturer

Laboratory exercise

14 hours, compulsory

Teacher / Lecturer