Electrons: probing their properties and collective dynamics

The complexity of the plasma state requires the use of experimental tools which can provide information on particle properties and dynamics. This is essential to understand processes such as: • energy exchange; • ionization dynamics; • development of plasma instabilities and particle transport, among other features. Information on these aspects is key to the development of theoretical models and numerical codes for all plasmas. Regardless of the plasma state and type (magnetized or unmagnetized, hot or cold, high or low pressure) electrons play a key role in determining the discharge features. Diagnosing their properties and dynamics is therefore critical.