1. Introduction 525
2. Qualitative picture of the processes occurring in a shock wave 526
3. Theoretical examination of the individual processes leading to the establishing of equilibrium 527
3.1. Establishing of the Maxwell distribution 527
3.2. Establishing of equilibrium in the vibrational degrees of freedom (vibrational relaxation) 528
3.3. Establishing of equilibrium in the rotational degrees of freedom (rotational relaxation) 531
3.4. Establishing of the equilibrium degree of dissociation 531
3.5. Establishing of the equilibrium degree of ionization 533
4. Functioning of a shock tube 534
5. Experimental methods for studying the state of a gas in a shock wave 537
5.1. Measurement of the density of the gas 537
5.2. Measurement of the concentrations of the components of the gas 538
5.3. Measurement of the intensity of radiation 539
5.4. Measurement of the temperature of the gas 541
5.5. Measurement of the concentration of electrons 543
5.6. Measurement of the pressure 544
5.7. Measurement of the speed of flow 544
6. Summary of results 545
6.1. The establishing of the Maxwell distribution (monatomic gas) 545
6.2. Rotational relaxation 545
6.3. Vibrational relaxation 546
6.4. Dissociation of diatomic molecules 547
6.5. Ionization 548
Literature cited 548