PHY 212-002 Van de Graaff Generator Shane Spivey Brendan Navarro, Grant Rold, Jacob Travers, Grace Waters

Abstract Build Diagram Results

A Van de Graaff generator is a device that works on the principles of the using a rotating belt to Time (seconds) accumulate charges on a surface. The material of the belt was varied in order to test the effectiveness of each material 20 40 60 to accumulate charges. The arc lengths produced using each Inconsistent Consistent Consistent of the belt materials was then measured, and the results Cotton Arc length: Not Arc length: ¼” Arc length: ¼” were as follows: the nylon belt produced the longest arcs, measurable the silk belt came in second with slightly shorter arc

Consistent Consistent Consistent Silk lengths, the cotton belt produced the smallest arcs, and the Arc length: ⅓” Arc length: ¼” Arc length: ¼” rubber belt was unable to consistently produce any sparks. This project demonstrated findings that were expected Consistent Consistent Consistent Nylon based on the triboelectric series. Belt Material Arc length: ½’’ Arc length: ½’’ Arc length: ½’’

Inconsistent Inconsistent Inconsistent Background Rubber Arc length: Not Arc length: Not Arc length: Not measurable measurable measurable American physicist Robert Van de Graaff invented the Van de Graaff generator in 1931. Conclusion This machine is a high- electrostatic Build Process generator that serves as a in a In conclusion, the designed Van de Graaff generator was able variety of fields including medicine, industry The frame of the machine was built using PVC pipes, to produce arcs between itself and the discharge rod. These and nuclear studies. In order to operate, the and two rollers were attached to the frame. Near each arcs varied in length and consistency which was dependant on device depends on the distribution of charge on a of the rollers, copper wire brushes were attached in the belt material. The test results were compared to the moving belt made of an insulating fabric. This order to pick up charges from the belt. A hollow triboelectric series in order to confirm accuracy. Nylon, charge is transferred from the belt into a metal sphere was attached to the top of the generator, having produced the greatest arc length and consistency spherical metal shell. The sphere increases in and it was connected to the top brush using a wire. A overall, does appear to have caused the greatest potential until an electric breakdown discharge wand was then connected to the bottom difference. Rubber, on the other hand, produced inconsistent occurs.The main objective of a Van de Graaff brush. Four belts were then constructed using nylon, and immeasurable arcs. This does reflect the triboelectric generator is to maximize the amount of charge cotton, silk, and rubber. A drill was then attached to model where rubber is considered a neutral material. accumulation through the contact of dissimilar the bottom roller to rotate the belt. Each belt was then materials. mounted onto the machine and tested.