Demonstrations

Stellar Fusion - Nuclear Fusion Model

Image #2

Code Number :	8B10.05
Disclaimer:	Reprinted by permission of Dick Berg, University of Maryland, for use on this website. The demonstrations contained and referenced herein are listed for the purposes of cataloging and describing physics demonstrations which should be conducted only under the direction of a trained instructional support professional or physicist. These demonstrations are not presented for the purpose of being conducted by persons unconnected to this Facility and/or persons not consulting with or being supervised by the recognized instructional support professional or physicist and his/her staff. The University is responsible only for those demonstrations carried out using its own equipment using established safety and scheduling policies, and bears no responsibility for those choosing to use this source material for their own purposes. All demonstrations described and contained herein are public domain, and can also be found in reference materials in libraries, bookstores, and electronic sources. Further information regarding legal liability in use of demonstrations and labs will be found on the web site Injuries in School/College Laboratories in USA. The University of Iowa Disclaimers: University of Iowa Disclaimer All Rights Reserved..
Condition :	Excellent
Principle :	Fusion
Area of Study :	Astronomy
Equipment :	Nuclear Fusion Model, Air Track, two cars of the same mass with large magnets.
Procedure :	Place the cylinders into the vertically held Plexiglas tube. When the green ends are facing each other, the system is simulating two electrons approaching each other, and they are always repulsive, independent of distance. When the orange ends are facing each other, the system is simulating two protons approaching each other. They are repulsive at large distances, but at small distances the repulsive force goes to zero and they become strongly attractive. This is the analogy of the electrostatic repulsion that dominates at large distances, and of the strong attractive component of the nuclear force responsible for the energy released in fusion. ( The above is excerpted from the Kashy and Johnson reference below ). Place one of the cars near the middle of the air track with the magnet on the car facing the oncoming car. As you gently collide the cars they will repel each other without touching. If you collide the cars at greater velocities the magnetic repulsion will be overcome and the cars will touch.

References

E. Kashy, D. A. Johnson, "A Model to Illustrate Forces in Nuclear Fusion", AJP, Vol. 62, # 9, Sept. 1994, p. 804.

Robert Ehrlich, "Nuclear Fusion Simulation," Why Toast Lands Jelly-Side Down, p. 180-181.

Mail Questions and Comments to: Dale Stille