Peter Driggers, age 17, of Jackson, Miss., for his question:

WHAT DOES THE VAN DE GRAAFF GENERATOR DO?

The Van de Graaff generator is a device for building up a high electrical charge. It is a source of charged particles that may be used for atom smashing. It is also known as an electrostatic generator.

In general, the Van de Graaff generator is used to boost protons and other nuclear particles to an energy of about 10 million electron volts. The chief value of the machine is that narrow beams of protons or known energies can be produced. These beams are used to study  nuclear forces.

Robert J. Van de Graaff, an American physicist, made the first generator of this kind at the Massachusetts Institute of Technology in 1931.

In the generator, a continuous belt of an insulating material moves past a source of negative electricity. This source sprays electrons on the belt. The belt then goes into a hollow metal dome where a fine metallic brush moves the electrons onto the dome surface. When the charge at the top of the dome is high enough, electrically charged particles are hurled at targets at the bottom of the generator.