Demonstrations

Radioactivity Demo

Code Number :	7D10.10
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 :	Natural and Artificial Radioactive Sources
Area of Study :	Modern Physics
Equipment :	Geiger counter with special cord (Cord has a low pass filter built in), Radioactive sources (all), Amplifier, Speaker, Aero-Ektar lens.
Procedure :	Plug the speaker into the speaker outputs of the amplifier. Plug the Geiger counter into the auxiliary input of the amplifier. Turn the amplifier on and turn the Geiger counter on to the desired scale. Bring the radioactive source close to the counter tube and hear the audible clicks. The radioactive sources are all labeled except for the large rock. The radioactivity is concentrated in the dark bands of the rock. Salt substitute usually contains KCl as the active ingredient. Natural potassium has a significant amount of ⁴⁰K which is one of the most abundant radioactive substances with a half-life of 1.277 billion years. The counting rate heard should be 3 to 4 times background. Many of the old style lantern mantles use thorium as the main ingredient. The most abundant radioisotope of thorium is²³²Th with a 14.05 billion year half-life. Another cheap radioactive source can be purchased at the camera store. This is an anti-static brush that is used to neutralizes the static charge on dust and then wipe it away. A small amount of Polonium 210 is used for this neutralization. This brush with source will last for several years before it needs to be replaced. This is a very good source to use for the electrostatic discharge of a parallel plate capacitor (5D40.30). The Aero-Ektar lens is a World War II aerial reconnaissance lens. To get the high index of refraction needed for a fast lens two elements of the compound lens were doped with Thorium. To test for radioactivity screw off the back mount part of the lens so that you can get the detector close to the back side of the lens. A count rate similar to the uranium plate should be heard.

Web Sites

"The Aero-Ektars" http://home.earthlink.net/~michaelbriggs/aeroektar/aeroektar.html

"Radioactive Products and Other Sources of Radiation," Chris Smolinski, www.blackcatsystems.com

References

David R. Lapp, "Teaching Nuclear Radiation and the Poisoning of Alexander Litvinenko", TPT, Vol. 46, # 3, March 2008, p. 160.

"Figuring Physics", TPT, Vol. 43, # 3, May 2005, p. 303.

Christopher G. Deacon, "A Background to Background Radiation," TPT, Vol. 41, # 2, p. 78, Feb. 2003.

"Figuring Physics", TPT, Vol. 38, # 6, Sept. 2000, p. 346.

Douglas E.Peplow, "Fiestaware™ Radiography", TPT, Vol. 37, # 5, p. 316, May 1999.

Ludwik Kowalski, "Will New Technology Solve the Nuclear Waste Problem?", TPT, Vol. 35, # 1, Feb. 1997, p. 126.

Carson A. Riland, "Environmental Radioactivity, Temperature, and Precipitation", TPT, Vol. 34, # 4, Apr. 1996, p. 234.

Howard C. Hayden, "Erratum", TPT, Vol. 34, # 1, Jan. 1996, p. 4.

Gary Kessler, "Recycle Outmoded Air-Track Components", TPT, Vol. 33, # 7, Oct. 1995, p. 473.

Howard C. Hayden, "High-Level Radioactive Waste", TPT, Vol. 33, # 7, Oct. 1995, p. 450.

Michael C. Boyer, "Environmental Radioactivity and the Weather," TPT, Vol. 33, # 9, p. 554-555, Dec. 1995.

Jack G. Couch, Kelly L. Vaughn, "Radioactive Consumer Products in the Classroom," TPT, Vol. 33, # 1, p. 18, Jan. 1995.

Lawrence Ruby, "If You Understand Leaky Buckets, You Understand A Lot of Physics", TPT, Vol. 29, # 1, Jan. 1991, p. 44.

Richard E. Berg, "More Leaky Buckets", TPT, Vol. 29, # 5, May 1991, p. 266.

Jordan Koss, Kenneth Hartt, "Beta Decay", TPT, Vol. 26, # 7, Oct. 1988, p. 471.

John E. Peterson, "The Energy Crisis Is Still With Us," TPT, Vol. 24, # 7, p. 444, October 1986.

G. Stroink, "Radiation Safety in the Lab", TPT, Vol. 18, # 3, Mar. 1980, p. 207.

Ronald A. Kobiske, "Those Betas Can Make a Difference", TPT, Vol. 18, # 6, Sept. 1980, p. 406.

Peter Lindenfeld, "Does Doctor Always Know Best?", TPT, Vol. 15, # 6, Sept. 1977, p. 325.

Stewart C. Bushong, "The Author Replies", TPT, Vol. 15, # 6, Sept. 1977, p. 382.

David A. Smith, "A Negative MPD?", TPT, Vol. 15, # 7, Oct. 1977, p. 388.

Stewart C. Bushong, "Radiation Exposure in Our Daily Lives", TPT, Vol. 15, # 2, Feb. 1977, p. 135.

J. C. Widman, J. Brnetich and E. R. Powsner, "A Radioactive Decay Flow Diagram", TPT, Vol. 13, # 9, Dec 1975, p. 554.

Michael Davis, "What's a Spinthariscope?", TPT, Vol. 12, # 7, Oct. 1974, p. 406.

Karl Z. Morgan, " Comments on Radiation Hazards and Risks", TPT, Vol. 9, # 7, Oct. 1971, p. 415.

Florence G. Freilich, "Radiation and People", TPT, Vol. 8, # 9, Dec. 1970, p. 499.

John W. Sulcoski, "Making Inexpensive Accessories for Nuclear Education", TPT, Vol. 7, # 5, May 1969, p. 300.

James Barker, "Spinthariscopes, TPT, Vol. 7, # 4, April 1969, p. 244

Frederic W. Kantor, "Using Polaroid Land Sheet Film Packets For Radiation Experiments and Demonstrations", TPT, Vol. 3, # 3, March 1965, p. 170.

Edith H. Quimby, " Safe Use of Ionizing Radiation In Secondary Schools", TPT, Vol. 3, # 4, April 1965, p. 158.

A. S. Eve, "Early History of Radioactivity", TPT, Vol. 1, # 5, Nov. 1963, p. 240.

Alberto De Gregorio, "Radioactivity Induced by Neutrons: Enrico Fermi and a Thermodynamic Approach to Radiative Capture", AJP, Vol. 74, # 7, July 2006, p. 614.

A. J. Howard, S. E. Carroll, and W. P. Strange, "A Simple System for Radon-in-Air Concentration Determinations." AJP, Vol. 59, No. 6, June 1991.

Bernard L. Cohen, "The Nuclear Reactor Accident at Chernobyl, USSR", AJP, Vol. 55, # 12, Dec. 1987, p. 1076.

P. J. Ouseph and Andrew Mostovych, "An Experiment to Measure Range, Range Straggling, Stopping Power, and Energy Straggling of Alpha Particles in Air", AJP, Vol. 46, # 7, July 1978, p. 742.

Lawrence Badash, "Radioactivity Before the Curies", AJP, 33, # 2, Feb. 1965, p. 128.

MPa-2: Freier and Anderson, A Demonstration Handbook for Physics.

S-250: "Chips-Cups-Nickels-Dominoes," DICK and RAE Physics Demo Notebook.

Frederick Sietz and Eugene P. Wigner, "The Effects of Radiation on Solids", Reprinted from Scientific American, Aug. 1956.

Joseph C. McDonald, Bert M. Coursey, and Michael Carter, "Detecting Illicit Radioactive Sources", Physics Today, Nov. 2004, p. 36.

"It's Radioactive!" Uncle John's Bathroom Reader, 2007, p. 195.

Dick Goodspeed, "Teaching Tip! Whole Body Radiation," Equipment & Supplies Safety. D149.

Isaac Asimov, "Into the Here," Fantasy and Science Fiction Magazine, pp. 138.

Isaac Asimov, "Out of the Everywhere," Fantasy and Science Fiction Magazine, pp. 129.

Isaac Asimov, "Skimming the Nearest," Fantasy & Science Fiction, pp. 115.

Isaac Asimov, "The Unrecognized Danger," Fantasy & Science Fiction Magazine, pp. 108.

Isaac Asimov, "Royal Gamma," Fantasy & Science Fiction. p. 130.

"Emission Characteristics of Alpha Particles," Selective Experiments in Physics, CENCO, 1962.

"Experiments in Radioactivity," Selective Experiments in Physics, CENCO, 1962.

Mail Questions and Comments to: Dale Stille