The call Van de Graaff generator was conceived by the American engineer Jemison Van de Graaff, in 1929, with the objective of reaching high tensions. This equipment was essential for conducting research on the constitution of atoms and nuclear research.
O generator it consists of a motor capable of moving a belt made of insulating material. The belt rubs on the underside with a wire brush connected to the negative or positive electrode of a source. this movement electrifies the friction belt, which goes up on the left side (see figure), is electrified. Upon reaching the top, the belt touches a second brush, which is in contact with the spherical layer of the generator. electrical charges of opposite signal to the belt penetrate through it, leaving the generator sphere electrically charged and capable of generating high electrical voltages around it.
Van de Graaff generator structure
From the moment the accumulated charges of the metallic sphere create a electric field at 30 KV/cm, the air in the vicinity of the conductor will undergo an ionization process, the so-called corona effect, which will limit the accumulation of electrical charges in the sphere.
O Van de Graaff generator can be used in physics laboratories for the study of frictional electrifications, electrical charges, dielectric strength etc.
By Joab Silas
Graduated in Physics
Source: Brazil School - https://brasilescola.uol.com.br/fisica/gerador-van-graaff.htm
