Written by established experts in the field, this book features in-depth discussions of proven scientific principles, current trends, and applications of nuclear chemistry to the sciences and engineering.
* Provides up-to-date coverage of the latest research and examines the theoretical and practical aspects of nuclear and radiochemistry
* Presents the basic physical principles of nuclear and radiochemistry in a succinct fashion, requiring no basic knowledge of quantum mechanics
* Adds discussion of math tools and simulations to demonstrate various phenomena, new chapters on Nuclear Medicine, Nuclear Forensics and Particle Physics, and updates to all other chapters
* Includes additional in-chapter sample problems with solutions to help students
* Reviews of 1st edition: "... an authoritative, comprehensive but succinct, state-of-the-art textbook ...." (The Chemical Educator) and "...an excellent resource for libraries and laboratories supporting programs requiring familiarity with nuclear processes ..." (CHOICE)
WALTER D. LOVELAND, PhD, is a professor of chemistry at Oregon State University, USA.
DAVID J. MORRISSEY, PhD, is a professor of chemistry and associate director of the National Superconducting Cyclotron Laboratory at Michigan State University, USA.
GLENN T. SEABORG, PhD (deceased), was a professor of chemistry at the University of California, Berkeley, and cofounder and chairman of the Lawrence Hall of Science, USA. He is credited with discovering 10 new elements, including plutonium and one that now bears his name, seaborgium. In 1951, Dr. Seaborg and his colleague, Edwin McMillan, were awarded the Nobel Prize in Chemistry for research into transuranium elements.
Nuclear chemistry consists of a four-pronged endeavor made up of (a) studies of the chemical and physical properties of the heaviest elements where detection of radioactive decay is an essential part of the work, (b) studies of nuclear properties such as structure, reactions, and radioactive decay by people trained as chemists, (c) studies of macroscopic phenomena (such as geochronology or astrophysics) where nuclear processes are intimately involved, and (d) application of measurement techniques based on nuclear phenomena (such as activation analysis or radiotracers) to study scientific problems in a variety of fields. The principal activity or "mainstream" of nuclear chemistry involves those activities listed under (b).
As a branch of chemistry, the activities of nuclear chemists frequently span several traditional areas of chemistry such as organic, analytical, inorganic, and physical chemistry. Nuclear chemistry has ties to all branches of chemistry. For example, nuclear chemists are frequently involved with the synthesis and preparation of radiolabeled molecules for use in research or medicine. Nuclear analytical techniques are an important part of the arsenal of the modern analytical chemist. The study of the actinide and transactinide elements has involved the joint efforts of nuclear and inorganic chemists in extending knowledge of the periodic table. Certainly the physical concepts and reasoning at the heart of modern nuclear chemistry are familiar to physical chemists. In this book we will touch on many of these interdisciplinary topics and attempt to bring in familiar chemical concepts.
A frequently asked question is "what are the differences between nuclear physics and nuclear chemistry?" Clearly, the two endeavors overlap to a large extent, and in recognition of this overlap, they are collectively referred to by the catchall phrase "nuclear science." But we believe that there are fundamental, important distinctions between these two fields. Besides the continuing close ties to traditional chemistry cited previously, nuclear chemists tend to study nuclear problems in different ways than nuclear physicists. Much of nuclear physics is focused on detailed studies of the fundamental interactions operating between subatomic particles and the basic symmetries governing their behavior. Nuclear chemists, by contrast, have tended to focus on studies of more complex phenomena where "statistical behavior" is important. Nuclear chemists are more likely to be involved in applications of nuclear phenomena than nuclear physicists, although there is clearly a considerable overlap in their efforts. Some problems, such as the study of the nuclear fuel cycle in reactors or the migration of nuclides in the environment, are so inherently chemical that they involve chemists almost exclusively.
One term that is frequently associated with nuclear chemistry is radiochemistry. The term radiochemistry refers to the chemical manipulation of radioactivity and associated phenomena. All radiochemists are, by definition, nuclear chemists, but not all nuclear chemists are radiochemists. Many nuclear chemists use purely nonchemical and therefore physical techniques to study nuclear phenomena, and thus, their work is not radiochemistry.
1.2 The Excitement and Relevance of Nuclear Chemistry
What do nuclear chemists do? Why do they do it? Who are the nuclear chemists? What is exciting and relevant about nuclear chemistry? The answers to these questions and many more similar questions are what we will discuss in this book.
Nuclear chemists ask questions about the sizes of things like nuclei and their constituents. But because nuclear reactions are what makes the stars shine, the laboratory for many nuclear chemists is the universe with attention focusing on supernova and neutron stars (the largest known "nuclei"). The size scale for the nuclear chemistry laboratory ranges from zeptometers (10 m) to zettameters (1021 m). Nuclear chemists are always trying to make/discover new things about the natural world. From using radioactivity to measure the temperature of the planet Earth to tracing the flow of groundwater or the circulation patterns of the oceans, nuclear chemists explore the natural world. What makes the stars shine or how do they shine? A nuclear chemist, Ray Davis, won the 2002 Nobel Prize in Physics for his pioneering work on the neutrinos emitted by the sun (see Chapter 12).
Speaking of Nobel Prizes, the junior authors (WDL, DJM) would be remiss not to mention that our coauthor (GTS) won the 1951 Nobel Prize in Chemistry for his discoveries in the chemistry of the transuranium elements. In total, nuclear chemists and physicists have discovered 26 new elements, expanding the fundamental building blocks of nature by about 30%. The expansion of the nuclear landscape from the 3000 known nuclei to the 7000 possibly bound nuclei remains an agenda item for nuclear science. Understanding why only about 228 of these nuclei are stable is also important.
Understanding the sizes and shapes of nuclei remains an important item. Shapes such as spherical, oblate, prolate, and hexadecapole are all observed; sometimes there are coexisting shapes even in the decay products of a single nucleus, such as 190Po, which decays to spherical, oblate and prolate-shaped products. Some nuclei like 11Li appear to have spatially extended structures due to weak binding that make them huge.
The applications of nuclear chemistry to the world around us enrich our lives in countless ways. One of these ways is the application of nuclear chemistry to the diagnosis and treatment of disease (nuclear medicine). Over 400 million nuclear medicine procedures are performed each year for the diagnosis of disease. The most widely used (over 10 million procedures/year) radionuclide is 99Tcm, which was discovered by one of us (GTS). Positron emission tomography (PET) is used in over 1.5 million procedures/year in the United States. In PET, compounds of short-lived emitters, like 18F, are injected into a patient, concentrating in particular organs. When the positron emitters decay, the particles contact ordinary electrons, annihilating to produce two 0.511?MeV photons moving in opposite directions. When enough of these photon pairs are detected, one can form an image of the location of the decay. Studies of these images can be used to understand the location of tumors, brain functions, and so on. Targeted radiopharmaceuticals can be used to deliver a radiation dose to a specific location in the body.
Nuclear chemistry plays a role in our national security. In the United States, 300 portal monitors detect the possible entry of clandestine nuclear material. Several of these monitors employ advanced technologies to combat sophisticated schemes to shield the clandestine material. In the event of a nuclear radioactivity release, such as what occurred at the Fukushima reactor complex in Japan, simple ray spectroscopy of exposed air filters has proven to be useful.
Nuclear power remains an important source of electricity for several countries. Nuclear chemists play key roles in waste remediation from nuclear power plants and providing solutions for nuclear fuel cycle issues. As chemists, they are also able to contribute to studies of material damage in reactor components.
There is a significant demand for people trained as nuclear chemists and radiochemists. In the United States, the demand for trained nuclear chemists at the PhD level exceeds the supply by a factor of 10 and has done so for decades.
1.3 The Atom
Before beginning a discussion of nuclei and their properties, we need to understand the environment in which most nuclei exist, that is, in the center of atoms. In elementary chemistry, we learn that the atom is the smallest unit a chemical element can be divided into that retains its chemical properties. As we know from our study of chemistry, the radii of atoms are 1 to m, that is, 1-5?Å. At the center of each atom, we find the nucleus, a small object ( 1 to m) that contains almost all the mass of the atom (Fig. 1.1). The atomic nucleus contains Z protons where Z is the atomic number of the element under study. Z is equal to the number of protons and thus the number of positive charges in the nucleus. The chemistry of the element is controlled by Z in that all nuclei with the same Z will have similar chemical behavior. The nucleus also contains N neutrons where N is the neutron number. Neutrons are uncharged particles with masses approximately equal to the mass of a proton ( 1 u). The protons have a positive charge equal to that of an electron. The overall charge of a nucleus is electronic charge units.
Figure 1.1 Schematic representation of the relative sizes of a lithium atom and its nucleus. The nucleus is too small to be represented in the image of the atom even with the smallest printable dot.
Most of the atom is empty space in which the electrons surround the nucleus. (Electrons are small, negatively charged particles with a charge of electronic charge units and a mass of about 1/1840 of the proton mass.) The negatively charged electrons are bound by an electrostatic (Coulombic) attraction to the positively charged nucleus. In a neutral atom, the number of electrons in the atom equals the number of protons in the nucleus.
Quantum mechanics tells us that only certain discrete values of...