• Study of the structure of the atom;
• Study of collisions of free electrons with neutral atoms during the flow of electric current in a rarefied gas;
• Experimental determination of the first excitation potential of argon atoms.

The setup is based on a four-electrode vacuum tube filled with argon at low pressure. In addition to the tube, the housing contains its power supply circuit and measuring circuits, including digital current and voltage sensors, which allow monitoring the accelerating voltage and collector current.

The dependence of the collector current on the accelerating voltage is recorded on the computer screen with a smooth increase in the voltage supplied to the anode. When processing the obtained curve, the values ​​of the accelerating voltage (electron energy) at which the collector current reaches its maximum values ​​are read using a marker. The value of the argon excitation potential is calculated as the average value of the difference in voltage of two adjacent maxima on the curve.