Plasma Physics Teaching Laboratory
Bachelor’s Degree
The Plasma Physics Teaching Laboratory, located in U2-2025, houses activities related to the “Plasma Physics Laboratory” course, one of the thematic laboratory elective courses available to third-year students. The laboratory is equipped with several experimental apparatuses, which allow the study of a variety of methodologies for generating and diagnosing plasmas at both low pressure and atmospheric pressure.
With regard to low-pressure plasmas, there is a hot-cathode machine for the production of a beam-driven plasma, in helium or argon, generated by an electron beam emitted from a glowing filament and confined by an axial magnetic field. The machine, equipped with a pumping system consisting of a rotary pump and a turbomolecular pump, enables the study of the generation of this type of plasmas, and also the learning of the Langmuir probe diagnostic method.
Also in the area of low-pressure plasmas, two tubes, connected to rotary pumps, are available for the study of the initiation of DC plasmas, with the construction of Paschen curves in different gases, and for the study of the formation of capacitively coupled radiofrequency plasmas. The plasmas produced in these two apparatuses are also diagnosed by the use of spectrometers that analyze the emitted visible radiation.
In the area of atmospheric pressure plasmas, an apparatus is available for the study of dielectric barrier discharges (DBDs), in which it is possible to learn the mode of generation of these plasmas, their spectroscopic diagnostics, and it is possible to measure the effects on air chemistry using ozone sensors.
Finally, there is an apparatus for the study of corona discharge and ionic wind production, which allows the evaluation of the dependence of airflow velocity and thrust produced as the discharge parameters change.
Another activity that is also carried out in this laboratory is learning the principles of spectrometer operation through an activity of building and calibrating such an instrument.
Master's Degree
The Plasma Physics Teaching Laboratory, located in U2-2025, houses activities related to part of the “Laboratory of Plasma Physics I” course.
A hot-cathode machine is available in this laboratory for producing a beam-driven plasma, in helium or argon, generated by an electron beam emitted from a glowing filament and confined by an axial magnetic field. The machine, equipped with a pumping system consisting of a rotary pump and a turbomolecular pump, is used to study oscillations at the plasma frequency, detected by means of a probe immersed in the plasma and connected to a suitable receiver. Through analysis of the spectrum detected by the probe in the microwave range, a measurement of the plasma density results. The same experiment is also repeated by generating the plasma by radio frequency applied to a magnetized electrode, using the electron beam only for excitation of the oscillation.
Also available in the laboratory is an apparatus for studying vacuum production and measurement, consisting of a chamber connected to a pumping system consisting of a rotary pump and a turbomolecular pump. This system is used to study pumping curves, evaluate conductances and pumping rates, and to carry out leak detection exercises. In addition, it is equipped with a mass spectrometer, by means of which the composition of residual gases at various pressures can be analyzed, and exercises can be carried out to identify trace amounts of volatile substances fed into the chamber.
The laboratory is also equipped with a numerical computing station, on which a Particle-In-Cell (PIC) plasma simulation code is installed. It can be used to simulate various phenomena, and in particular the oscillations at the plasma frequency that are measured on the hot cathode machine. This type of activity allows for learning methods of spatiotemporal spectral analysis of data sets.