Chapter 9 Nuclear Radiation

1. Chapter 9 Nuclear Radiation 9.7 Energy of the Nucleus

2. Energy of the Nucleus • Mass-to-Energy Conversion • Mass can be converted to energy during nuclear reactions. • E = mc2. • Binding Energy • The mass of a nucleus is always less than the sum of the masses of its constituent nucleons. • This mass defect was converted to the “binding energy” that holds the nucleons together.

3. Application of Nuclear Chemistry Such as the study of the chemical effects resulting from the absorption of radiation within living animals, plants, and other materials. The radiation chemistry controls much of radiation biology as radiation has an effect on living things at the molecular scale, to explain it another way the radiation alters the biochemicals within an organism, the alteration of the biomolecules then changes the chemistry which occurs within the organism, this change in biochemistry then can lead to a biological outcome. As a result nuclear chemistry greatly assists the understanding of medical treatments (such as cancerradiotherapy) and has enabled these treatments to improve.

4. Varian Clinac 2100C Linear Accelerator Radiation therapy (or radiotherapy) is the medical use of ionizing radiation as part of cancertreatment to control malignantcells (not to be confused with radiology, the use of radiation in medical imaging and diagnosis). Radiotherapy may be used for curative or adjuvant cancer treatment. It is used as palliative treatment (where cure is not possible and the aim is for local disease control or symptomatic relief) or as therapeutic treatment (where the therapy has survival benefit but is not curative). Total body irradiation (TBI) is a radiotherapy technique used to prepare the body to receive a bone marrow transplant. Radiotherapy has a few applications in non-malignant conditions, such as the treatment of trigeminal neuralgia, severe thyroid eye disease, pterygium, prevention of keloid scar growth, and prevention of heterotopic ossification. The use of radiotherapy in non-malignant conditions is limited partly by worries about the risk of radiation-induced cancers.

5. Alternative energy sources using nuclear energy, such as nuclear power plants and reactors. iodine-131 radioactive Dye injected into a Human body

6. Energy of the Nucleus (cont) • Fission • Following splitting (fission) of the uranium-235 nucleus, the masses of the products are less than the masses of the reactants. • The “missing mass” is released as energy. • The Manhattan Project • The Manhattan Project was the code name for the effort to develop a fission-based atomic bomb during World War II.

7. A neutron bombardinga heavy nucleus begins fission The nucleus breaks Into smaller pieces, releasing a lot of energy Fission event is within an atom bomb is initiated by a neutron (gray) bombarding a heavy nucleus such as uranium.

8. 4 Major Research Teams involved in the Manhattan Project • The existing Metallurgical Laboratory at the University of Chicago, charged with the creation of a sustained nuclear fission chain reaction. • A new laboratory near Knoxville, Tennessee (now known as the Oak Ridge National Laboratory), charged with the enrichment of U-235 • A new laboratory in Hanford, Washington, charged with the production, isolation and purification of Pu-239 • A new laboratory in Los Alamos, New Mexico, directed by J. Robert Oppenheimer, charged with the design and construction of the atomic bomb.

9. The now-familiar mushroom cloud of the Trinity test Credit: Corbis

10. August 6th, 1945 “Little Boy” dropped on Hiroshima, Japan August 9th, 1945 “Fat Man” dropped on Nagasaki, Japan

11. Nagasaki before (top) and after (bottom) Hiroshima before (top) and after (bottom)