Submitted by Prof. Calvin Howell The Triangle Universities Nuclear Laboratory (TUNL) is involved with activities associated with the Nuclear Science Merit Badge of the Boy Scouts of America. As part of this outreach to young people, TUNL offers science presentations, hands-on activities and tours of the research facilities that are appropriate for a wide age range (7th grade through high school students).
This fall (September 10, 2011) Boy Scout Troop 101 from Asheville, NC visited TUNL as part of their activities toward obtaining a Nuclear Science Merit Badge. The troop leaders were Jeff Cole, Ruth Johnson, Tony Johnson and Cissy Williams. Tony Johnson is a Duke graduate (class of 1987) and an Iron Duke. The scout's visit to Duke was facilitated by Sally Schatz of the Duke Athletics Department.
Their visit to TUNL was coupled with their attending the Duke vs. Stanford football game. The group consisted of nine scouts of ages from about 12 to 16 years old. The scouts arrived around 9 am. Chris Westerfeldt and Prof. Calvin Howellgave presentations. Howell’s presentation was a general overview of nuclear matter and nuclear binding in the context of the other natural forces. Howell told the scouts that nuclear binding energy is about a million times greater than chemical binding, that the diameter of the nucleus, which is at the core of the atom, is about ten thousand times smaller than the diameter of the atom and that stars are powered by nuclear reactions that release the tremendous amount of energy stored in the nucleus. He asked them to imagine sitting in the stands at the football stadium and a fly lands in the middle of the field. The relative size of the fly to the field is about the same as that of the nucleus of the atom. In continuing this analogy with the fly as the nucleus and the spectators as the electrons in an atom, he said that the fly would weigh about 2,000 times more than the people in the stands. Howell’s presentation also included a brief history of the advancement of knowledge about the subatomic world by making note of the contributions of some of the key people, e.g., Henri Becquerel, Marie and Pierre Curie, Ernest Rutherford, Lise Meitner, Enrico Fermi and Hans Bethe. Chris Westerfeldt’s presentation included descriptions of the types of radiation, how radiation interacts with matter, typical radiation exposure rates and how we might reduce our exposure to radiation. The discussion of radon in his presentation was a big hit with the scouts. Several scouts inquired how they might obtain radon testing kits.
After the presentations the scouts toured the DFELL/HIGS facility and the Tandem Laboratory. The scouts participated in two measurements that we carried out in the Tandem Laboratory. One measurement demonstrated the relationship between radiation intensity and distance from a nearly point source. The second measurement illustrated the difference in the effectiveness of different types of materials to shield against gamma-ray radiation. The material studies were plastic, aluminum, iron and lead. TUNL graduate students David Ticehurst (UNC) and Dustin Combs (NC State) assisted the scouts with the measurements.