|
Hello and welcome! So you want to learn a little about the history of radiation? You came to the right place!
Welcome to Jenni's Radiation Research and Events Timeline
This page was last updated June 12th, 2006
Please send comments or suggestions to Jennifer Di Palma at:
(email given is an image to avoid spambots)
• Glossary of Terms |• Images |• Sources| • Home (Dr. Scott's web site)
|
| Year
| Event
|
1801
| • Johann W. Ritter discovered ultraviolet radiation when he placed silver chloride, which darkens in violet light, in the colorless area next to the color spectrum from a prism. It darkened, proving the existence of another wave form higher than the violet of visible light
• Sir William Hershel discovered infrared radiation
|
| 1895
| • X-rays are discovered by Wilhelm Konrad Roentgen
|
1896
| • Antoine-Henri Becquerel discovered Natural radioactivity when a mineral containing uranium darkened a covered photographic plate. The new radiation was dissimilar to X-ray radiation, and occurred without any external stimulus
• X-ray pictures used as evidence in a court of law for the first time in history
• Heinrich Rubens and Ernest Fox Nichols at the University of Berlin discovered tetrahertz radiation
|
1898
| • Marie and Pierre Curie discover polonium and another new radioactive element, which they name “radium”
• Gamma rays are discovered by Paul Ulrich Villard
• Two forms of radioactivity are discovered by Ernest Rutherford: alpha rays and beta rays
• Beta rays are proved to consist of high-speed electrons by Fritz Geisel, Antoine-Henri Becquerel, and Marie Curie
|
| 1899
| • W.H. Rollins conducts experiments which show that X-rays are lethal to mammals
|
| 1901
| • The atomic disintegration theory of radioactivity, which states atomic nuclei split to form other elements, is presented to the public by Ernst Rutherford and Frederick Soddy in a paper entitled “The Cause and Nature of Radioactivity”
|
| 1902
| • George Perthes finds X-rays are able to inhibit tumor growth; and he suggests they might be useful in the treatment of cancer
|
| 1903
| • Results from experiments conducted by C.R. Bardeen illustrate that X-rays induce mutations in toads
|
1905
| • Einstein publishes his famous equation of relativity: E = mc2 (energy equals mass times the velocity of light squared). This equation became a cornerstone in the development of nuclear energy. Click here to view the Einstein Archives Online
|
| 1907
| • X-rays are used to help diagnose digestive tract disorders
|
| 1910
| • Cosmic radiation is discovered by Victor Hess, who discovers that the ionization of air increases with altitude
|
1912
| • X-rays are proved to be a form of electromagnetic radiation by Max Von Laue. He demonstrates that X-rays create diffraction patterns with crystals
• A radiation detector, the Geiger counter, is revealed by its creator Hans Geiger
|
| 1913
| • Ernest Rutherford reports seeing a nuclear reaction when he observed that alpha particles passing through nitrogen gas were absorbed and protons emitted. He concluded that nitrogen nuclei had been transformed into oxygen via the reaction
|
| 1919
| • Film badges to measure radiation exposure are developed
|
| 1922
| • The Geiger-Muller counter is applied to detecting and measuring the intensity of radiation
|
| 1926
| • H.J. Muller proves that X-rays can induce mutations in Drosophila melanogaster, and that the occurrence of mutations increases as the level of X-ray dosage applied increases
|
| 1927
| • Bone cancer is observed in employees painting radium dials and is attributed to alpha radiation
• The Big Bang Theory is proposed as an explanation for the origin of the universe. Click here to go to NASA’s web site about the Big Bang.
|
| 1929
| • X-rays are used to examine the kidney, ureter, and bladder
• A high-voltage X-ray machine is developed for therapeutic applications by Charles Lauritsen
|
| 1930
| • The cyclotron is invented by Ernest Lawrence
|
1931
| • The Van de Graaff generator is designed and built by Dr. Robert J. Van de Graaff, who was a professor at MIT; the generator was originally used as a research tool in early atom-smashing and high energy X-ray experiments
• The existence of the neutron is established by Englishman James E. Chadwick
|
| 1932
| • Enrico Fermi works out a detailed theory of Beta decay
|
| 1934
| • The possibility of an atomic chain reaction is discovered by Otto Hahn, who splits the atom for the first time
|
1938
| • Enrico Fermi receives the Nobel Prize for his “discovery of new radioactive elements produced by neutron irradiation, and for the discovery of nuclear reactions brought about by slow neutrons”. Click here to read more on the U.S. Department of Energy Research & Development Accomplishments Web Site
• Frederic and Irene Joliot-Curie demonstrate that an atomic chain reaction result from the fission of the uranium atom
|
| 1939
| • Fission reactions are demonstrated by Leo Szilard and Walter Zinn to be self-sustaining due to chain reactions
• Maurice Goldhaker ascertains that beryllium slows fast neutrons which makes them more likely to fission uranium
|
| 1940
| • Glen Seaborg, Edwin McMillan, Joseph Kennedy, and Arthur Wahl isolate Plutonium. Click here to read more on the U.S. Department of Energy Research & Development Accomplishments Web Site
|
| 1941
| • Glen Seaborg isolated Uranium-233, and established thorium’s nuclear fuel potential
• The U.S. government conceives and executes the top-secret Manhattan project, which is created to produce the first atomic bomb
|
1942
| • Los Alamos, New Mexico is chosen as the site for the atom bomb laboratory
• Enrico Fermi leads a team of physicists to create the first controlled atomic chain reaction in a mound of uranium and graphite
• A radiation dose of 4 Roentgens a day is proved to be dangerous to humans by H.M. Parker
• Enrico Fermi supervises the design and assembly of an “atomic pile”, later known as a “nuclear reactor”
• Clinton (now Oakridge) Laboratory in Oakridge, Tennessee activates the world’s first nuclear reactor
• C. Southam and J. Erlich introduce the notion of hormesis, a beneficial side effect of low-dose radiation
|
| 1943
| • Glenn Seaborg formulates his “actinide concept” of heavy element electronic structure
|
| 1944
| • Alvin M. Weinberg, a nuclear physicist and future Director of the Oak Ridge National Laboratory, is quoted telling the Senate’s Special Committee on Atomic Energy that, “Atomic power can cure as well as kill. It can fertilize and enrich a region as well as devastate it. It can widen man’s horizons as well as force him back into the cave.”
|
1945
| • In the desert outside of Alamogordo, New Mexico the first atomic bomb is exploded
• America’s second atomic bomb, named “Little Boy”, is dropped on Hiroshima, Japan
• America’s third atomic bomb, named “Fat Man”, is dropped on Nagasaki, Japan
• President Truman mandates that the National Academy of Sciences commence studies of the long-term direct effects of the atomic bomb on survivors
|
1946
| • Physicist Maria Goeppert Mayer develops her “nuclear shell model” explanation of how neutrons and protons within atomic nuclei are structured. Her work explains why nuclei of some atoms are more stable than others, and why some elements have different atomic forms, called “isotopes”. Click here to read about her discovery on the U.S. Department of Energy Research & Development Accomplishments Web Site
(Image to the left courtesy of Argonne National Laboratory)
|
| 1948
| • The Mayak plutonium facility is put into operation producing plutonium for nuclear weapons in the USSR
|
| 1949
| • Radiocarbon dating (Carbon-14 dating) is developed by J. R. Arnold and W. F. Libby; it becomes one of the most widely used and best known dating methods
• The U.S. conducts atomic testing of nuclear weapons in the Pacific.
• President Truman requests additional programs to test nuclear weapons in the continental U.S.
• The USSR explodes it first atomic bomb
(Photo to the left (c) 1998 Smithsonian Institution; courtesy National Portrait Gallery)
|
| 1950
| • Glenn Seaborg and E.M. McMillan share the Nobel Prize in Chemistry for “discoveries in the chemistry of the transuranium elements”
|
1952
| • Edward Teller leads a team to build the first Hydrogen bomb
• Great Britain detonates its first atomic bomb
• The Atomic Energy Commission builds a “breeder reactor”, able to simultaneously produce both plutonium and energy from uranium fissioning
• D.A. Glaser invents the bubble chamber, which uses superheated liquid to trace the paths of charged particles and the interactions of their nuclei
• Evidence for solar X-rays are discovered by Herbert Friedman
|
| 1956
| • The first Hydrogen bomb is exploded by America over Bikini Atoll in the Pacific
• A public report is released by the National Academy of Sciences Committee stating that there is no safe threshold for radiation exposure; this sparks the ongoing debate among prominent members of the scientific and political communities about the specific hazards of radiation to the world population. Click here to visit the National Academy of Sciences web site
• A buried nuclear waste canister explodes at a Soviet weapons plant near Kyshtym, forcing the evacuation of 10,000 people
|
| 1957
| • Nuclear bomb fallout is declared harmful to humans by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR)
|
| 1958
| • Between 1944 and 1958 Glenn Seaborg discovered 8 elements related to uranium: americium, curium, berkelium, californium, einsteinium, fermium, mendelevium, and nobelium. When element 106 was discovered, it was named after him, seaborgium
• France explodes its first atomic bomb
|
| 1960
| • A key route of entry of radionuclides from fallout into the human body is determined to be inhalation. The Lovelace Foundation for Medical Education and Research initiates studies on the effects of inhaling such radionuclides, and later goes on to study the inhalation of aerosols of other radioisotopes related to nuclear reactor accidents. Today, the organization is known as Lovelace Respiratory Research Institute
• A.R. Bleich publishes a book: The Story of X-Rays (New York: Dover); this book later becomes the inspiration for Matthew C. Beard's famous paper, "Progress towards two-dimensional biomedical imaging with THz spectroscopy". (2003)
In his paper, Mr. Beard writes: “Imaging capabilities are of fundamental importance in medicine and biology. Ever since Wilhelm Roentgen produced the striking x-ray image of Professor von Kolliker’s hand, including his ring, during a public lecture on 23 January 1896, the medical community has been acutely aware of the tremendous possibilities afforded by the ability to visualize or capture an image that cannot be observed with the naked eye.”
|
1961
| • Maria Goeppert Mayer shares the Nobel Prize in Physics for her work regarding her “nuclear shell model”
click here to view a larger image of the Nuclear Shell Model
| 1963
| • 100 nations sign a treaty that bans nuclear weapons testing in the atmosphere
• China detonates its first atomic bomb
|
| 1964
| • Plutonium is released into the atmosphere during a partial meltdown of a reactor outside of Annan, Scotland
|
1967
| • Alice Stewart and George Kneale publish a study proving that children in England and Wales have an increased risk of cancer due to radiation from obstetric X-rays
|
| 1970
| • A report is published by the National Academy of Science’s Biological Effects of Ionizing Radiation Committee I (BEIR I) which recommends using the Linear No-threshold (LNT) model for estimating radiation exposure risks. The LNT model presumes that any radiation exposure leads to increased risk of cancer
|
| 1972
| • The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) issues a report questioning the validity of the LNT model approach to estimating radiation risks. This sparks the ongoing debate over the ability of the model
• India explodes its first atomic bomb
|
| 1974
| • A nuclear reactor in Three Mile Island, Pennsylvania experiences a meltdown causing radioactive emissions to be spread over a multistate area. Reports state that doses to the public were very low and harmless
|
| 1979
| • T. Luckey publishes a monograph in the CRC Press that suggests low doses of radiation are good for you. This stimulates review of hormesis theory
|
| 1981
| • From 1967 to 1985 Dr. Raymond Davis, Jr. consistently studied neutrinos. He was quoted as saying “Neutrinos are fascinating particles, so tiny and fast that they can pass straight through everything, even the earth itself.”
Dr. Davis was the first scientist to detect solar neutrinos
|
| 1982
| • The Health Physics Journal publishes an article by M. Brucer that fires up the radiation hormesis debate. The title of this article is “Radiation is Good for You”
• John N. Bahcall and Raymond Davis, Jr. published a paper entitled "An Account of the Development of the Solar Neutrino Problem", in 1982. Click here to view it (PDF format)
|
| 1983
| • The adaptive response in cells is demonstrated to be a protective mechanism against radiation-induced chromosomal aberrations by researchers at the University of California, San Francisco
|
| 1984
| • Information indicating that low doses of radiation are beneficial is presented at a conference on radiation hormesis in Oakland, California. Key information was published by the Health Physics Journal (1987)
|
| 1986
| • Irradiated food was made available for the first time in history at a farmer’s market in Miami, Florida
• In a controlled experiment, technicians at the Chernobyl Power Plant in the Ukraine allowed the power in the fourth reactor to fall to dangerously low levels causing a series of unforeseen complications, and resulting in a major meltdown
• A book tracing the historical development of the theory of hormesis is published, entitled Biological Effects of Low Level Exposure to Chemicals and Radiation.
The book is based on a workshop held in May of 1991 at the University of Massachusetts and was edited by Mr. Edward J Calabrese.
|
| 1992
| • George Bush, Sr. announces that the U.S. will no longer produce plutonium or enriched uranium for nuclear warheads
• Bill Clinton implements the Advisory Committee on Human Radiation Experiments to identify federally funded ionizing radiation experiments on humans in the U.S. Click here to view their web site
|
| 1994
| • DOE is directed by Congress to initiate the Low Dose Radiation Research Program (LDRRP) to establish science-based risk assessment standards and guidelines for exposures to low levels of low-LET ionizing radiation. Information on the program can be found by clicking here
|
| 1998
| • Pakistan detonates its first atomic bomb
• Radiation is approved for use to eliminate microorganisms in all lamb, beef, pork, goat, and veal products by the U.S. Department of Agriculture.
|
| 1999
| • Scientists at the Fred Hutchinson Cancer Research Center studies and finds no evidence that an increased thyroid cancer rate was caused by the release of Iodine-131 from the Hanford Site
(Photo to the left by Harley Soltes of The Seattle Times; http://seattletimes.nwsource.com/html/home/)
|
| 2000
| • Energy Secretary Bill Richardson announces plans to compensate U.S. workers suffering from ill effects of occupational exposure to radiation
• The NCRP published an evaluation of the LNT (Linear No-threshold) model for ionizing radiation and recommended that it continue to be used in radiation protection
|
| 2001
| • NATO medical chiefs begin research on the potential risks from depleted uranium munitions
• Dr. Raymond Davis, Jr. receives the Nobel Prize in Physics for “pioneering contributions to astrophysics, in particular for the detection of cosmic neutrinos”. Click here to read more on the U.S. Department of Energy Research & Development Accomplishments Web Site
(Photo to the left Courtesy of Brookhaven National Laboratory)
|
| 2004
| • Nonlinearity in Biology Toxicology and Medicine, publishes a special issue with papers proving that low doses of gamma radiation can protect against cancer occurrence. Co-editors are Drs. B.R. Scott and R.E.J. Mitchel
The protection is based on activation of DNA repair and/or apoptosis of precancerous cells and has important implications for cancer prevention and cancer therapy
|
|
Radiation Research and Events Glossary
• Top (Back to The Timeline)
• Radiation Research & Events Images
• Sources •
Home (back to Dr. Scott's web site)
|
| Term
| Definition
|
| Actinide concept
| A prediction that the actinides – including the first 11 transuranium elements- would form a transition series analogous to the rare earth series of lanthanide elements
back to text
|
| Adaptive response
| The adaptive response involves using a small dose of a given agent (e.g. X rays) to induce natural protection from exposure to a higher dose of the same or a different agent. The small adapting dose can also suppress spontaneously occuring effects such as mutations.
back to text
|
| Alpha rays (Alpha particles)
| A particle made up of two protons and two neutrons. Alpha particles are emitted by some heavy elements that include uranium, plutonium, and radon. Alpha particles can be stopped by a piece of paper and are only a concern when alpha-emitting isotopes are taken into the body (e.g., by inhalation). Many Russian nuclear workers inhaled large amounts of plutonium-239 while working at the Mayak plutonium production facility located in the Chelyabinsk region near Siberia. As a result, some of the Mayak workers developed serious health effects including lung cancer *
back to text
|
| Apoptosis
Disintegration of cells into membrane-bound particles that are then eliminated by phagocytosis or by shedding; a form of “cell suicide”
back to text
|
| Astrophysics
The branch of astronomy that deals with the physics of stellar phenomena
back to text
|
| Atomic chain reaction
A reaction where fissile atoms (e.g., atoms of uranium-235) absorb neutrons, then split, releasing energy and more neutrons, which in turn cause additional atom splittings and neutron releases so that the process continues. Nuclear weapons that were exploded over Japanese cities of Nagasaki and Hiroshima were based on uncontrolled chain reactions. Radiation exposures resulting form the weapons mainly involved gamma rays but also neutrons. Although the radiation exposures occurred in the forties, radiation induced cancers are still occurring among A-bomb survivors *
back to text
|
| Atomic disintegration theory of radioactivity
States that atomic nuclei split to form other elements. To read the article that was published by Ernest Rutherford and Frederick Soddy, click here
back to text
|
| Beryllium
The fourth lightest element. Beryllium is used to make some parts for nuclear weapons and can be harmful if taken into the body *
back to text
|
| Beta Decay
Beta decay is one process that unstable atoms can use to become more stable through emitting electrons. There are two types of beta decay, beta negative and positive
back to text
|
| Beta rays (Beta particles)
An electron (positive or negative) emitted during decay of some isotopes. Beta particles have a short range in air and even shorter range in more dense material. Beta-emitting isotopes (e.g. strontium-90) deposited on the skin can cause skin burns and other more serious effects. Japanese fishermen (in a boat called the Lucky Dragon) were exposed to atmospheric fallout from a U. S. thermonuclear test explosion conducted in 1954 in the Pacific Ocean and developed severe skin burns. Beta radiation burns to a large area of the skin can be lethal *
back to text
|
| Breeder reactor
A nuclear reactor that produces as well as consumes fissionable material, especially one that produces more fissionable material than it consumes
back to text
|
| Chromosomal aberration
A deviation from the proper or expected course in the threadlike linear strand of DNA and associated proteins in the nucleus of eukaryotic cells that carry the genes and functions in the transmission of hereditary information
back to text
|
| Cosmic radiation
Radiation originating in outer space *
back to text
|
| Cyclotron
A cyclotron is a machine used to accelerate charged particles to high energies and speeds
back to text
|
| DNA repair
Each cell has a series of special enzymes to correct the errors in DNA structure and sequence. This protects genetic information against environmental damage and replication errors and restore the DNA to its original state
back to text
|
| Drosophila melanogaster
The common fruit fly, used to study the basic mechanisms of inheritance
back to text
|
| Electromagnetic radiation
Radiation consisting of waves of energy associated with electric and magnetic fields resulting from the acceleration of an electric charge
back to text
|
| Fallout (atmospheric fallout)
Radioactive particles from a nuclear explosion. The particles gradually fall from the sky and deposit on the ground and on other surfaces *
back to text
|
| Fission
The splitting (breaking apart or fissioning) of the nucleus of a heavy atom such as uranium-235 or plutonium-239. The fission is usually caused by the absorption of a neutron *
back to text
|
| Gamma rays (Gamma radiation)
High-energy, penetrating radiation emitted in the radioactive decay of many radionuclides. Gamma rays are similar to X rays, but X rays generally have lower energy. A dose of three gray of gamma rays delivered briefly to the total body would be lethal to about 50% of humans exposed because of severe damage to the hematopoietic system. Deaths would be expected to occur within about 60 days. However, spreading the 3 gray dose over a number of years would be expected to lead to far less net damage to the hematopoietic system. Some nuclear workers in Russia exposed over years, at low rates, to up to 10 gray of gamma rays survived. However, 10 gray delivered briefly to the total body would be considered lethal for all persons exposed *
back to text
|
| High-speed electrons
High-speed electrons are known as beta particles (see beta rays definition)
back to text
|
| Hormesis
An effect where a toxic substance acts like a stimulant in small doses, but it is an inhibitor in large doses
back to text
|
| Hydrogen bomb
A nuclear weapon that releases atomic energy by union of light (hydrogen) nuclei at high temperatures to form helium
back to text
|
| Infrared radiation (AKA Infrared light)
Infrared light lies between the visible and microwave portions of the electromagnetic spectrum. Infrared light has a range of wavelengths, just like visible light has wavelengths that range from red light to violet. "Near infrared" light is closest in wavelength to visible light and "far infrared" is closer to the microwave region of the electromagnetic spectrum. The longer, far infrared wavelengths are about the size of a pin head and the shorter, near infrared ones are the size of cells, or are microscopic
back to text
|
| Iodine-131
Heavy radioactive isotope of iodine with a half-life of 8 days; used in a sodium salt to diagnose thyroid disease and to treat goiter. For image, click here
back to text
image of an isotope atom
|
| Irradiated food
Food treated with radiation to kill harmful organisms such as bacteria
back to text
|
| Isotopes
Forms of the same chemical element that have different numbers of neutrons. Many isotopes are produced in nuclear reactors and particle accelerators. The field of nuclear medicine depends on a constant supply of radioactive isotopes (i.e., radioisotopes) *
back to text
|
| LET
Short for linear energy transfer. LET represents the average amount of radiation energy lost when traversing a small distance *
back to text
|
| Meltdown
Severe overheating of a nuclear reactor core, resulting in melting of the core and escape of radioactive material
back to text
|
| Microorganism
An organism of microscopic or submicroscopic size, especially a bacterium or protozoan
back to text
|
| Munitions
War materiel, especially weapons and ammunition. Often used in the plural
back to text
|
| Natural radioactivity
The naturally-occurring spontaneous emission of radiation from unstable atoms. Radionuclides lose particles (e.g., alpha or beta) and energy through radioactive decay *
back to text
|
| Neutrinos
Neutrinos are neutral particles that rarely interact with matter. They have a nearly zero mass.
back to text
|
| Neutron
Neutrons are uncharged particles found within atomic nuclei
back to text
|
| Nuclear reactor
Any of several devices in which a chain reaction is initiated and controlled, with the resulting heat typically used for power generation and the neutrons and fission products used for military, experimental, and medical purposes
back to text
|
| Plutonium
This is a man-made element. Pure plutonium (Pu) is a silvery metal that is heavier than lead. Plutonium found in the environment is often in the oxide form. This form is generally written as PuO2 *
back to text
|
| Precancerous cells
Of, relating to, or being a condition that typically precedes or develops into a cancer, e.g. a precancerous growth
back to text
|
| Radionuclides
Radioactive species of an atom *
back to text
|
| Radium
A rare, brilliant white, luminescent, highly radioactive metallic element found in very small amounts in uranium ores, having 13 isotopes with mass numbers between 213 and 230, of which radium 226 with a half-life of 1,622 years is the most common. It is used in cancer radiotherapy, as a neutron source for some research purposes, and as a constituent of luminescent paints.
back to text
|
| Roentgen
A unit of radiation exposure equal to the quantity of ionizing radiation that will produce one electrostatic unit of electricity in one cubic centimeter of dry air at 0°C and standard atmospheric pressure
back to text
|
| Slow neutrons
Conventionally defined as neutrons whose kinetic energy is below 1 eV. Slow neutrons frequently undergo elastic scattering interactions with nuclei and may in the process transfer a fraction of their energy to the interacting nucleus
back to text
|
| Solar neutrinos
Neutrino particles produced in the nuclear reactions that power the sun
back to text
|
| Solar X-rays
Solar X-ray emissions can consist of X-ray background flux or X-ray bursts. X-ray bursts are a temporary enhancement of the X-ray emission of the sun
back to text
|
| Tetrahertz radiation
Radio waves sent at terahertz frequencies, known as terahertz radiation or terahertz waves, are in a waveband that is the overlap of what is normally regarded as microwave radiation and far-infrared light.
back to text
|
| Thorium
A radioactive element found in nature *
back to text
|
| Threshold
A dose below which there is considered no risk of harm
back to text
|
| Thyroid cancer
Cancer of the thyroid gland. Thyroid cancer is a form of cancer that can occur in all age groups, particularly those who have had significant exposure to ionizing radiation.
back to text
|
| Transuranium element
Any of the chemical elements that lie beyond uranium in the periodic table (those with atomic numbers greater than 92)
back to text
|
| Uranium
A naturally occurring material used for nuclear technology. There are a variety of uranium isotopes that include uranium-235 and uranium-238 *
back to text
|
| Uranium-233
Isotope of Uranium
back to text
|
| X-rays are able to inhibit tumor growth
For some cancers, radiation therapy—either from an external beam or from implanted radioactive pellets—is the primary treatment. The usual forms are X rays and gamma rays. Use of radioactive elements specific for particular target organs, such as radioactive iodine specific for the thyroid gland, is effective in treating malignancies of those organs; see the encyclopedia.com section on cancer treatment: http://www.encyclopedia.com/html/section/cancer_Treatment.asp
back to text
|
| X-rays
Penetrating photon radiation often used in medical diagnosis. Sunlight is also a form of photon radiation but less hazardous than X rays *
back to text
|
| * From Dr. Bobby Scott’s Radiation Glossary for Students, URL: http://www.lrri.org/radiation/radgloss.htm
|
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |