A Brief Chronology of Radiation and Protection

 

by

 

J. Ellsworth Weaver III

 

1994 - 2006

 

Is it right to probe so deeply into Nature's secrets? The question must here be raised whether it will benefit mankind, or whether the knowledge will be harmful.  Radium could be very dangerous in criminal hands.  Alfred Nobel's discoveries are characteristic; powerful explosives can help men perform admirable tasks.  They are also a means to terrible destruction in the hands of the great criminals who lead peoples to war... -- Pierre Curie in his Nobel Prize Oration, June 6,1905

 

 

 

Permission is given to copy this but not for sale or as part of any “for profit” transaction.

 

 

 

 

For an updated version contact the author at JEW1@PGE.COM or

phone (805) 545-3029

1,800,000 BC   First “reactor accident.”  Concentration of enriched uranium forms natural nuclear reactor at Oklo, Gabon and becomes critical; core burns for 200,000 years.

 

500 BC Democritus and Leucippus of Greece postulate that all matter is made of indivisible units they call "atomos." "For by convention color exist, by convention bitter, by  convention sweet, but in reality atoms and void."-- Galen quoting one of Democritus' 72 lost works.

 

450 BC Greek philosopher Anaxagoras states that matter cannot be created nor destroyed.

 

79 AD  First known use of uranium. Roman artisans produce yellow colored glass in mosaic mural near Naples.

 

1400 AD Mysterious malady kills miners at an early age in mountains around Schneeberg (Saxony) and Joachimsthal (Jachymov) in the Sudetenland (now Czechoslovakia). Called "mountain sickness."

 

1669   Phosphorous discovered by Hennig Brand (Germany).

 

1704   "It seems probable to me that God in the beginning formed matter in solid, massy, hard, impenetrable, movable particles, of such sizes and figures, and with such other properties, and in such proportion to space, as most conduced to the end to which he formed them."

                     --Sir Isaac Newton.

 

1735   Platinum discovered by Julius Scaliger (Italy).

 

1737   Cobalt discovered by George Brandt (Sweden).

 

1746   Zinc discovered by Andreas Marggraf (Germany).

 

1751   Nickel discovered by Axel Cronstedt (Sweden).

 

1766   Hydrogen discovered by Henry Cavendish (England).

 

1772   Nitrogen discovered by Daniel Rutherford (Scotland).

 

1774   Oxygen discovered by Joseph Priestly (England) and Carl Wilhelm Scheele (Sweden).

 

1774   Chlorine discovered by Carl Wilhelm Scheele (Sweden).

 

1774   Manganese discovered by Johann Gahn (Sweden).

 

1778   Molybdenum discovered by Carl Wilhelm Scheele (Sweden).

 

1782   Tellurium discovered by Franz Mueller von Reichenstein (Romania).

 

1783   Tungsten discovered by Fausto and Juan Jose de Elhuyar (Spain).

 

1784   William Morgan unknowingly produces X-rays in experiment witnessed by Ben Franklin.

 

1789   (Sept 24) Martin Klaproth announces his discovery of a new element, uranium.

 

1789   Zirconium discovered by Martin Klaproth (Germany).

 

1790   Strontium discovered by A. Crawford (Scotland).

 

1791   Titanium discovered by William Gregor (England).

 

1794   Yttrium discovered by Johann Gadolin (Finland).

 

1797   Chromium discovered by Louis Vauquelin (France).

 

1798   Beryllium discovered by Fredrich Woehler (Germany) and A. A. Bussy (France).

 

1800   William Herschel (Germany-USA) discovers a point below the frequency of red light which he terms infrared.

 

1801   Johann Wilhelm Ritter (Germany) discovers light beyond the violet end of the spectrum which he terms ultraviolet.

 

1801   Niobium discovered by Charles Hatchet (England).

 

1802   Tantalum discovered by Anders Ekeberg (Sweden)

 

1803   "Thou knowest no man can split the atom." -- John Dalton

 

1803   Palladium discovered by William Wollaston (England).

 

1803   Cerium discovered by W. von Hisinger, J. Berzelius, M. Kaproth (Sweden / Germany).

 

1804   Rhodium discovered by William Wollaston (England).

 

1804   Iodine discovered by Bernard Courtois (France).

 

1804   Osmium discovered by Smithson Tenant (England).

 

1804   Iridium discovered by S. Tenant, A.F. Fourcory, L.N.  Vauquelin, and H.V. Collet-Descoltils (England / France).

 

1807   Sodium discovered by Sir Humphrey Davy (England).

 

1807   Potassium discovered by Sir Humphrey Davy (England).

 

1808   Magnesium discovered by Sir Humphrey Davy (England).

 

1808   Calcium discovered by Sir Humphrey Davy (England).

 

1808   Barium discovered by Sir Humphrey Davy (England).

 

1808   John Dalton (England) formulates the Chemical Atomic Theory which states that elements combine in fixed proportions of their masses.

 

1811   Amedeo Avogadro (Italy) states equal volumes of all gases contain equal number of molecules under conditions of fixed temperature and pressure.

 

1816   William Prout (England) postulates that all atoms are made of multiples of the hydrogen atom.  His work, although published anonymously, becomes known as "Prout's Hypothesis."

 

1817   Lithium discovered by Johann Arfvedson (Sweden).

 

1817   Selenium discovered by Jons Berzelius (Sweden).

 

1817   Cadmium discovered by Fredrich Stromeyer (Germany).

 

1823   Silicon discovered by Jons Berzelius (Sweden).

 

1824   Uranium described in Gmelin's Handbook. Much animal toxicity studies done thereafter.

 

1825   Aluminum discovered by Hans Christian Oersted (Denmark).

 

1825   Oersted observes that some undefinable magnetic effect is associated with charged particles in motion.

 

1826   Bromine discovered by Antoine J. Balard (France).

 

1828   Boron discovered by H. Day (England), J.L. Gay-Lussac and L.J. Thenard (France.)

 

1828   Thorium discovered by Jons Berzelius (Sweden).

 

1830   Vanadium discovered by Nils Stefstrom (Sweden).

 

1830   Michael Faraday (England) claims that moving charges (current) may be generated by moving magnetic fields.

 

1839   M. Daguerre discovers photography which later becomes the basis for personnel dosimetry and discovery of radioactivity in uranium.

 

1839   Lanthanum discovered by Carl Mosander (Sweden).

 

1843   Terbium discovered by Carl Mosander (Sweden).

 

1843   Erbium discovered by Carl Mosander (Sweden).

 

1844   Ruthenium discovered by Karl Klaus (Russia).

 

1845   (Mar 27) Wilhelm Roentgen is born.

 

1847   (Feb 11) Thomas Alva Edison is born.

 

1847   H. von Helmholz states that energy may be converted to other forms but may not be destroyed or lost.

 

1850  First commercial use of uranium in glass by Lloyd & Summerfield of Birmingham, England.

 

1852   (Dec 15) Henri Becquerel is born.

 

1856   Joseph John Thomson, first person to identify the existence of subatomic particles, born.

 

1859   Bunsen and Kirchhoff originate spectroscopy.

 

1860   Uranium is first used in homeopathic medicine for treatment of diabetes.

 

1860   Cesium discovered by Gustov Kirchhoff and Robert Bunsen (Germany).

 

1861   Rubidium discovered by Gustov Kirchhoff and Robert Bunsen (Germany).

 

1861   Thallium discovered by Sir William Crookes (England).

 

1863   Indium discovered by Ferdinand Reich and H. Richter (Germany).

 

1865   H. Geissler and J. Plucker observe fluorescence in evacuated tubes containing electrodes.

 

1868   (Mar 22) Robert Millikan is born.

 

1869   (Feb 14) C.T.R. Wilson is born.

 

1869   E. Goldstein coins phrase "cathode rays."

 

1869   Hittorf shows cathode emanation stopped by solid object.

 

1869   William Crookes notes fogging in photographic plates in his laboratory and complains of defective packaging. The fogging is actually caused by an unknown at the time radiation, x-rays, produced in Crookes' tubes.

 

1870   James Maxwell puts forth an extension of the theories of Michael Faraday and Orsted in a rigorous mathematical form: charge and the electric field; the magnetic field; magnetic effect of a charging electric field or moving charge; and the electric effect of a changing magnetic field.

 

1871   Ernest Rutherford is born.

 

1872   (July) Dmitri Ivanovitch Mendeleev, an unknown Siberian supervisor of weights and measures, presents paper in St. Petersburg detailing his Periodic Table of the Elements.

 

1873   (Oct 23) William Coolidge is born.

 

1875   Gallium discovered by Paul Emile Lecoq de Boisbaudron (France).

 

1876   Eugen Goldstein (Germany) coins the phrase "cathode rays."

 

1878   Holmium discovered by J.L. Soret (Switzerland).

 

1878   Ytterbium discovered by Jean de Marignac (Switzerland).

 

1879   (Mar 8) Otto Hahn is born.

 

1879   (Mar 14) Albert Einstein is born.

 

1879   W. Crookes shows cathode rays are solid matter with sufficient energy to drive a small wheel.

 

1879   Identification of the malady in Schneeberg mines as lung cancer. Thought to be lymphosarcomata, the causation remains murky.

 

1879   Scandium discovered by Lars Nilson (Sweden).

 

1879   Samarium discovered by Paul Emile Lecoq de Boisbaudron (France).

 

1879   Thulium discovered by Per Theodor Cleve (Sweden).

 

1880   Gadolinium discovered by Jean de Marignac (Switzerland).

 

1881   George Johnstone Stoney (Ireland) names the indivisible unit of electricity the electron.

 

1882   (Sept 30) Hans Geiger is born.

 

1883   (June 24) Victor Hess is born.

 

1884   Balmer (Switzerland), a high school teacher, finds that gases bombarded by electrons will emit electromagnetic waves of only certain wavelengths which he measures with a grating spectroscope.

 

1884   Joseph John Thomson, aged 28, becomes Director of the Cavendish Laboratory at Cambridge University.

 

1885   (Aug 1) George de Hevesy is born.

 

1885   (Oct 7) Niels Bohr is born.

 

1885   Praseodymium discovered by C.F. Aver von Welsbach (Austria).

 

1886   H. Hertz characterizes long wave electromagnetic radiation.

 

1886   Goldstein notices rays going the opposite way from cathode rays channeling through a hole in the cathode.  He names them "channel rays."  These are later found to be the positive ions of the wisps of gas in the tube or parts of the cathode.

 

1886   Fluorine discovered by Henri Moissan (France).

 

1886   Germanium discovered by Clemens Winkler (Germany).

 

1886   Dysprosium discovered by Paul Emile Lecoq de Boisbaudron (France).

 

1887   (Nov 23) Henry Moseley is born.

 

1890   (Mar 31) W.L. Bragg is born.

 

1890   (Dec 21) Hermann Muller is born.

 

1891   (July 10) Edith Quimby is born.

 

1891   H. Hertz, assisted by P. Lenard, studies the penetrating power of cathode rays.

 

1894   Argon discovered by Sir William Ramsey and Baron Rayleigh (Scotland). 

 

1895   (July 26) Marie and Pierre Curie marry.

 

1895   (Sept 2) Otto Glasser is born.

 

1895   (Nov 8) Roentgen discovers X-rays.

 

1895   (Dec 22) Roentgen X-radiographs his wife's hand.

 

1895   (Dec 28) Roentgen communicates the discovery of X-rays to the Wurzburg Society.

 

1895   Helium discovered by William Ramsey, Nilo Langet, and P.T. Cleve (Scotland and Sweden).

 

1895   Rutherford shows that "uranium emanation" has a spectral line of helium

 

1895-1900  Photographic emulsions and electroscopes are primary instruments used when radiation is discovered.

 

1896   (Jan 1) Roentgen sends radiographs to colleagues.

 

1896   (Jan 5) First newspaper account of X-rays is published.

 

1896   (Jan 6) The discovery of X-rays is cabled world-wide by the London Times.

 

1896   (Jan 7) Campel-Swinton make radiograph in UK.

 

1896   (Jan 23) Roentgen makes first demonstration regarding X-rays.

 

1896   (Jan 27) Arthur Wright produces radiograph at Yale University.

 

1896   (Jan 29) First therapeutic applications of X-rays (Grubbe, Voigt, Despeignes)

 

1896   (Feb 3) First diagnostic X-ray by Edwin Frost (US) & John Cox (Canada).

 

1896   (Feb) First x-ray picture of a fetus in utero.

 

1896   (Mar 1) X-rays are used by Italian army.

 

1896   (Mar 3) Becquerel demonstrates the radioactivity of uranium.

 

1896   (Mar) First application of X-rays in dentistry (C. Kells and W. Rollins).

 

1896   (Mar) Thomas Edison reports eye injuries from X-rays.

 

1896   (June) N. Tesla cautions experimenters not to get too close to X-ray tubes.

 

1896   Dr. D. W. Gage (McCook, NB.) writing in New York's "Medical Record," notes cases of hair loss, reddened skin, skin sloughing off, and lesions. "I wish to suggest that more be understood regarding the action of the x rays before the general practitioner adopts them in his daily work."

 

1897   (Sept 12) Irene Curie is born.

 

1897   (Nov 18) P. M. Blackett is born.

 

1897   (Jan 18) Roentgen Society of London is organized.

 

1897   J.J. Thomson demonstrates corpuscular nature of cathode rays. He theorizes that these electrons might be a constituent part of all matter. He reports the mass of the electron.

 

1898   (Feb 11) Leo Szilard is born.

 

1898   (Mar) Discovery of radioactivity of thorium by G. Schmidt.

 

1898   (Apr 12) Marie Sklodovska Curie announces the probable presence in pitchblende ores of a new element endowed with powerful radioactivity.

 

1898   (July 13) Polonium isolated from pitchblende by Marie & Pierre Curie.

 

1898   (July) Marie & Pierre Curie coin word "radioactivity."

 

1898   (Dec 26) Radium-226 isolated from pitchblende by Marie & Pierre Curie.

 

1898   Becquerel receives skin burn from radium given to him by the Curies that he keeps in his vest pocket. He declares, “I love this radium but I have a grudge against it!”

 

1898   Neon discovered by Sir William Ramsey and M.W. Travers (England).

 

1898   Krypton discovered by Sir William Ramsey and M.W. Travers (England).

 

1898   Xenon discovered by Sir William Ramsey and M.W. Travers (England).

 

1899   Radioactive gaseous emanation from thorium is described by Rutherford.

 

1899   Andre Louis Debiere (France) discovers actinium, a radioactive element (atomic number 89.)

 

1899   Rutherford finds two kinds of radiation, which he names alpha and beta, emitted from radium.

 

1900   Crookes shows that purified uranium has almost no radioactivity.  He suggests that uranium was not the origin of the radiation but some impurity in the uranium.

 

1900   Discovery of gamma rays by P. Villard.

 

1900   Thorium-234 discovered by Crookes.

 

1900   American Roentgen Ray Society (ARRS) founded.

 

1900   Friedrich Ernst Dorn discovers radon (atomic number 86), a radioactive daughter of uranium.

 

1900   Thorium beginning of use in gas mantles.

 

1900   Marie Curie explains natural transmutation as a decay of an unstable atom to one of a lower atomic weight.

 

1900   Planck's constant, h = 6.63 E-34 J s, is published.

 

1900   Thomson's "plum pudding" model of the atom is proposed.

 

1900-1924  Gradual development of mechanical electrometers.

 

1901   (Jan 3) First report of death due to X-rays is published.

 

1901   Becquerel confirms Crookes' statement about uranium not being the origins of the radiation but also shows that if uranium is left standing, its radioactivity increases.

 

1901   Europium discovered by Eugene Demarcay (France).

 

1901   Max Planck proposes that atoms could gain and lose energy only in discrete quantities (quantum).

 

1901   First Nobel prize in physics is awarded to Roentgen.

 

1902   (Apr) Radioactive spontaneous disintegration, the unaided transmutation of elements, observed and named by Soddy and Rutherford. 

 

1902   (June 1) Lauriston Taylor is born.

 

1902   Radium-224 (thorium X) discovered by Soddy and Rutherford.

 

1902   Rollins experimentally shows X-rays can kill higher life forms.

 

1902   Existence of radium verified by Curies by chemical methods; they obtain 0.1 g of pure radium from several tons of pitchblende.

 

1903   (June 25) Marie Curie accorded the title of doctor of physical science, with the mention of très honorable from the University of Paris, Sorbonne

 

1903   (Nov 12) Marie and Pierre Curie awarded the Nobel Prize for Physics.

 

1903   Sir William Crookes and, independently, Elster and Geitel discover that crystals of zinc sulfide emit tiny flashes of visible light (scintillations) when struck with alpha particles.  Rutherford quickly adopts this detector for his work.

 

1904   (Apr 22) J. Robert Oppenheimer is born.

 

1904   (Oct) Clarence Madison Dally, a glass blower at Thomas Edison's Menlo Park lab, is first person known to have been killed by x-ray exposure. Severely burned in 1896, he still works with x-rays until 1898. His death causes Edison to discontinue radiation work in his lab.

 

1904   Rutherford shows that alpha particles are helium atoms and works out the natural decay series.

 

1904   Radon and daughters identified as part of the uranium series. Work with animals begins, especially in Russia and France.

 

1904   Colormetric dosimetry system devised by Saboroud and Noire.

 

1904   Marie Curie publishes an observation that diamonds when exposed to radiation and later heated glow proportional to exposure. This is published in Research on Radioactive Substances . This is the basis for thermoluminescent dosimetry which waits until 1950 to be further developed.

 

1904   "If it were ever possible to control at will the rate of disintegration of radio elements, an enormous amount of energy could be obtained from a small amount of matter." --Ernest Rutherford.

 

1904   H. Nagaoka (Japan) publishes planetary hypothesis of atomic structure.

 

1904   Rutherford coins the term "half-life."

 

1905   (June 6) "Is it right to probe so deeply into Nature's secrets? The question must here be raised whether it will benefit mankind, or whether the knowledge will be harmful.  Radium could be very dangerous in criminal hands.  Alfred Nobel's discoveries are characteristic; powerful explosives can help men perform admirable tasks.  They are also a means to terrible destruction in the hands of the great criminals who lead peoples to war..." Pierre Curie in his Nobel Prize Oration delayed from 1903.

 

1905   (Sept 3) Carl Anderson is born.

 

1905   Einstein publishes Special Theory of Relativity E= mc2

 

1905   Einstein explains the Photoelectric Effect by introducing light quanta (photons of energy E = hv)

 

1905   Thorium-228 discovered by Hahn.

 

1905   Ionization unit proposed by M. Franklin.

 

1905   Boltwood calls attention that lead is found with uranium and suggests that lead might be the end product of uranium.

 

1906   (April 19) Pierre Curie killed by a horse-drawn wagon filled with military uniforms driven by Louis Manin on the streets of Paris, France.

 

1906   Ernest Rutherford conducts experiments where he bombards gold foil with alpha particles.  Most of the alphas pass through.  He theorizes that atoms are mostly space.

 

1906   Joseph John Thomson is awarded the Nobel Prize in physics for his theoretical and experimental investigations into the electron and the conduction of electricity by gases.

 

1907   (May 18) Robley Evans is born.

 

1907   Ionium (Th-230) discovered by Boltwood.

 

1907   Lutetium discovered by Georg Urbain (France).

 

1907   H. N. McCoy and W. H. Ross at the University of Chicago show that two different radioelements might be chemically identical.

 

1908   Ernest Rutherford is awarded the Nobel Prize in chemistry for his observations on radionuclide decay (transmutation).

 

1909   Ernest Rutherford observes one alpha particle in 8000 being bounced back from a thin gold foil. From this observation, he concludes that most of the atom's mass is conentrated in a small postively-charged nucleus.

 

1909   Robert Andrews Millikan using oil droplets measures the charge of an electron e= 1.60 E-19 C.

 

1910   (Apr 13) Herbert Parker is born.

 

1910   Curie unit defined as activity of 1 gram of radium.

 

1910   Soddy establishes the existence of isotopes, nuclides with the same number of protons but different number of neutrons.

 

1910   Animal work on distribution and excretion of radium (mostly in Europe). Radium begun to be used as nostrum.

 

1910   Jesuit Father Theodor Wulf measures radiation at ground level and at top of Eiffel Tower. Radiation increases at higher elevation. Suspects extraterrestrial origins of this radiation. Suggests balloonists measure dose rates.

 

1911   (Aug) Rutherford and Geiger discover that atoms are mostly space using alpha particles to bounce off thin gold foil. 

 

1911   Marie Curie awarded the Nobel Prize for Chemistry for the separation of radium from pitchblende.

 

1911   Soddy suggests that "the expulsion of the alpha particle causes the radioelement to change its position on the periodic table..."

 

1911   Charles Glover Barkla (England) shows certain x-rays predominate; these are termed characteristic x-rays.

 

1911   Microscope is used to count grain densities in photographic film.

 

1911   Charles Thomas Rees Wilson (Scotland) invents the cloud chamber which shows tracks of radiation in a supersaturated atmosphere.

 

1911   Georg von Hevesy (Hungary) conceives the idea of using radioactive tracers. Leads to Nobel Prize in 1943.

 

1911-1912  Victor Hess (Austrian) takes balloon rides to measure radiation at heights up to 5000 meters. Discovers cosmic radiation which he names "Hoehenstrahlung" (high altitude rays.)

 

1912 (July 16)  Patent granted to the Radium Ore Revigorator Co., 260 California St., San Francisco, CA for a device, the Revigorator, that charges water with radon, ushering in a 20-year craze in radioactive health crocks. Instructions read: “Fill jar every night, use hydrant or any good water, drink freely when thirsty and upon rising and retiring. Average six or more glasses daily. Scrub with stiff brush and scald monthly.”

 

1912   Arthritis patient dies because of Ra-226 injections.

 

1912   T. Christen puts forth concept of half value layer for shielding x or gamma radiation, i.e., only half the incident radiation will be stopped by each successive shielding layer.

 

1912   Max von Laue (Germany) uses the crystals of zinc sulfide to diffract x-rays and measure their wavelength.  He thereby proves the wavelike nature of x-rays.

 

WW I   Exposure of hundreds of girls to luminous paint compound for instrument dials in New York and Illinois.

 

WW I   Henry Gwyn-Jeffries Mosley killed at Gallipoli. Mosley, a student of Rutherford, had bombarded each of the known elements with a beam of electrons to show the number of electric charges in each nucleus was increased in regular steps between each element in the periodic table. 

 

1913   (Jan 31) A. S. Russell put forward that in beta decay the position of the element in the periodic table changes by one place.

 

1913   Hans Geiger unveils his prototype gas-filled radiation detector.

 

1913   Niels Bohr (Denmark) applies the newly invented quantum theory to atomic electron orbitals.  These stationary orbitals would allow an electron to orbit a nucleus without emitting energy.

 

1913   Soddy proposes the term "isotope" for atoms with the same number of protons and differing only in number of neutrons.

 

1914   H.G. Wells publishes The World Set Free set in 1956 predicts an alliance of England, France, and America against Germany and Austria. All the major cities of the world are destroyed by atomic bombs.

 

1914   Ernest Marsden, Rutherford's assistant, reports an odd result when he bombards nitrogen gas with alpha particles -- something is thrown back with much greater velocity.  This is the first report of nuclei fissioning.

 

1914   Franck-Hertz experiment demonstrates discrete atomic energy levels in collisions with electrons.

 

1915   (June) British Roentgen Society proposes standards for radiation protection workers; includes shielding, restricted work hours, medical exams; no limits because of lack of units for dose or dosimeters; voluntary controls. This is believed to be the first organized step toward radiation protection.

 

1915   (Aug) Robert Rich Sharp discovers the Shinkolobwe uranium deposit in the Congo. Mine averages 68% uranium; richest find in history and is on the surface. 

 

1916   A. Sommerfeld (Germany) modifies Bohr's model of electron orbitals to allow elliptical orbits.  

 

1917   Otto Hahn and Lise Meitner discover protactinium. 

 

1919   First artificial transformation of an element by performed by Rutherford, now Director of Cavendish laboratory; alpha particle on nitrogen causes the expulsion of oxygen and hydrogen.

 

1920   Luminous dial painting expanded to clock factories.

 

1920   American Roentgen Ray Society (ARRS) establishes standing committee  for radiation protection.

 

1920   Rutherford suggests additional neutral nuclear particle (later called a neutron). "Such an atom would have very novel properties. Its external field would be practically zero, except close to the nucleus, and, in consequence, it should be able to move freely through matter."

 

1920   James Chadwick in Rutherford's lab uses alpha particle scattering to determine the charges on the nucleus of copper, silver, and platinum.

 

1920-1930s  Much use of radon generators in hospitals for preparation of radon seeds.

 

1921   Suggestion that radium and radium emanation might be causative agent in cancer in miners taken seriously but not proven.

 

1921   British X-ray and Radium Protection Committee present its first radiation protection standards.

 

1922   American Roentgen Ray Society adopts radiation protection rules.

 

1922   Niels Bohr is awarded the Nobel Prize in physics for describing how orbital electrons absorb and emit energy.

 

1922   American Registry of X-ray Technicians founded.

 

1922   G. Pfahler recommends personnel monitoring with film.

 

1922   P. Auger and F. Perrin determine the charge on the nucleus of argon.

 

1922-1924  Suspicions develop around radium dial painter's jaw lesions.

 

1923   (Jan 30) Szamatolski links dial painter injuries to radium.

 

1923   (Feb 10) Wilhelm Roentgen dies.

 

1923   A.H. Compton reports wavelengths lengthened for bounced x-rays and gammas. Leads to Nobel prize for the "Compton Effect".

 

1923   A. Mutscheller puts forth first "tolerance dose" (0.2R/day).

 

1923   "There is no likelihood man can ever tap the power of the atom... Nature has introduced a few foolproof devices into the great majority of elements that constitute the bulk of the world, and they have no energy to give up in the process of disintegration."--Dr. Robert Andrews Millikan

 

1923   Hafnium discovered by Dirk Coster and Georg von Hevesy (Denmark).

 

1924   Description of jaw necrosis by dentist, Blum; attributed to radiation from deposited luminous paint.

 

1924   DeBroglie states that an electron has wave properties and assigns a wavelength to an electron much the same way Einstein assigns a mass to an electromagnetic wave in 1905. This standing wave allows an electron to exist a some distance from the nucleus without gaining or losing energy.

 

1924   Uhlenbeck and Goudsmit ascribe electron with intrinsic spin h/2.

 

1925   (July 1) First International Congress of Radiology is held, establishes International Commission on Radiological Units (ICRU).

 

1925   Physician, Martland, describes pathology of bone changes and anemia in radium dial painters.

 

1925  William Bailey introduces Radithor, a quack radium potion to cure sexual dysfunction and everything else.

 

1925   Rhenium discovered by Walter Noddak, Ida Takke, and Otto Berg (Germany).

 

1925   Mutscheller's "tolerance dose" for X-rays.

 

1925   Neodymium discovered by C. Aver von Welsbach (Austria).

 

1925   Pauli explusion principle states that two electrons cannot share orbitals and spin in the same atom at the same time.

 

1925   Heisenberg's first paper on quantum mechanics.

 

1925-1929  The saga of radium dial painters and iatrogenic cases unfolds.

 

1926   (July)  “Radium Treatment of Carcinoma of the Lower Lip” is published in Radiology, Vo. VII, No. 1.

 

1926   (Aug) “Radiation of Cancer of the Cheek” is published in Radiology, Vol. VII, No. 2.

 

1926   (Oct) “Treatment of Lingual Cancer by Radiation” is published in Radiology, Vol. VII, No. 4.

 

1926   (Oct) “The Treatment of Bladder Tumors with Metal Seeds Containing Radium Emanation” by Dr. Edward L. Keyes is published in The Journal of Medical Society of New Jersey.

 

1926   (Nov) “Radium Therapy in Rhinology” is published in Radiology, Vol. VII, No. 5.

 

1926   (Dec) “Radiation of Malignancy of the Maxillary Sinus” is published in Radiology, Vol. VII, No. 6.

 

1926   (Dec) “Irradiation of Diseased Tonsils” is published in Medical Journal & Record, 124:873.

 

1926   Erwin Shrodinger publishes the wave theory of matter demonstrating that matter at the atomic level behaves as it consists of waves.

 

1926   Edith Quimby devises film badge dosimeter with energy compensating filters.

 

1927   (Feb) Werner Heisenberg realizes that it is impossible to establish at any given instant both the momentum and location of a subatomic particle.  This is published as his Uncertainty Principle.

 

1927   (Sept) “Malignancy of the Larynx and Esophagus Treated by Radium Emanation” by Dr. Frank Richard Herriman is published in The Laryngoscope.

 

1927   Dutch Board of Health recommends tolerance dose equivalent to           15 R/year.

 

1927   H. Muller shows genetic effects of radiation.

 

1927   Herman Blumgart, a Boston physician, first uses radioactive tracers to diagnose heart disease.

 

1927   Birth of quantum electrodynamics, Dirac's paper on "The Quantum Theory of the Emission and Absorption of Radiation."

 

1927   The first death from polonium ingestion. The victim was Nobus Yamada, a Japanese researcher in Marie Curie's lab in France. In 1924, he worked with Curie's daughter Irene Joliot-Curie to prepare polonium sources. After returning home the next year, Yamada fell ill.

 

1928   Organization and first meeting of International Committee on X-ray and Radium Protection (predecessor of ICRP).

 

1928   Description of basis for Geiger-Mueller counter by Hans Geiger and Walter Mueller at the Physics Institute in Kiel (Germany).

 

1928   Second International Congress of Radiology establishes International Committee on X-ray and Radium Protection (predecessor of ICRP) and publishes first set of international radiation protection standards; Roentgen unit accepted.

 

1928   Organization of US Advisory Committee on X-ray and Radium Protection (predecessor of NCRP).

 

1928   Dirac's relativistic wave equation of the electron.

 

1929   R. d'E. Atkinson and F. G. Houtermans (Germany) theorize that energy from stars is a result of nuclear fusion.

 

1929   "The energy available through the disintegration of radioactive or any other atoms may perhaps be sufficient to keep the corner peanut and popcorn man going in our large towns for a long time, but that is all." --Dr.  Robert A. Millikan (hedging a bit on his statement of 1923).

 

1929   "Free air" ionization chambers used as primary standards.

 

1929   Nuclear track photographic plates developed.

 

1929   Osteogenic sarcoma (bone cancer) is proven in the dial-painter population.

 

1929   Advisory Committee on X-Ray and Radium Protection (ACXRP) formed in the US (forerunner of NCRP).

 

1929-1930  Fifty percent of miners dying at Joachimsthal have carcinoma of lung.

 

1929-1933  Collaborative work by Schlundt, Failla, et al, on radium metabolism in patients at Elgin State Hospital in Illinois.

 

1930   Bothe and Becker find that after bombarding beryllium with alpha particles a very penetrating, uncharged type of radiation is produced. They assume, wrongly, that it must be an electromagnetic wave. It is later proven by Chadwick to be the neutron.

 

1930   Invention of the cyclotron by E. O. Lawrence & MS Livingston at Berkeley.

 

1930   Bethe quantum-mechanical stopping-power theory.

 

1930s  Vacuum-tube electrometers gradually replace mechanical ones.

 

1930   Early count rate meter invented.

 

1931   (Jan 2) Lawrence operates first cyclotron.

 

1931   (May 16) NBS Handbook 15 is published.

 

1931   Van de Graaff electrostatic generator constructed.

 

1931   Linear accelerator is constructed by Sloan & Lawrence at Berkeley.

 

1931   "Alpha particles are probably the most potent and destructive agent known to science"--Martland

 

1931   The Roentgen adopted as unit of X radiation.

 

1931   Wolfgang Pauli postulates the existence of a subatomic particle Enrico Fermi dubs “neutrino,” a massless uncharged particle that carries energy and momentum.

 

1932   (Feb 17) Chadwick discovers the neutron using Bothe and Becker’s experimental set up.  He scoops the Joliot-Curies who believed their "beryllium rays" were another form of electromagnetic radiation.

 

1932   (Mar) Eben Byers, prominent Pennsylvania industrialist and playboy millionaire, dies of the effects of drinking "Radithor." Others follow.

 

1932   (Aug 2) Carl Anderson using a specially prepared cloud chamber discovers a particle with the same mass and opposite charge as an electron (positron) in cosmic rays. He wins the Nobel Prize for his discovery in 1936.

 

1932   "There is not the slightest indication that nuclear energy will ever be obtainable. It would mean that the atom would have to be shattered at will." --Dr. Albert Einstein

 

1932   G. Failla suggests limit of 0.1 R/day to whole body and 5 R/day to fingers; introduces concept of higher permissible dose to limited portions of body.

 

1932   Roentgen unit is defined as producing one E.S.U. of either sign in 1 cc of air at STP.

 

1932   Werner Heisenberg proposes that the nucleus is composed only of protons and neutrons.

 

1932    Port Radium on Great Bear Lake in Canada begins production. Mines Canada issues health warnings on radon gas and radioactive dust.

 

1933   (Sept 12) Leo Szilard envisions nuclear chain reaction.

 

1933   (Sept 12) "The energy produced by the atom is a very poor kind of thing. Anyone who expects a source of power from the transformation of these atoms is talking moonshine." --Lord Ernest Rutherford (after splitting the atom for the first time)

 

1933   (Oct) The 7th Solvay Conference in Brussels, Belgium is devoted to nuclear physics for the first time. Attendees include: Marie Curie, Rutherford, Bohr, Lise Meitner, Heisenberg, Pauli, Enrico Fermi, Chadwick, George Gamow, Irene and Frederic Joliot-Curie, Patrick Blackett, Rudolf Peierls, Ernest Lawrence.

 

1933   DuBridge and Brown compensating circuit, vital for gas-filled radiation detectors,  is invented.

 

1933   First effort to reduce radium body burden by manipulation of diet and administration of parathyroid hormone.

 

1934   (Jan 11) First artificially produced radionuclide (P-30 from aluminum bombarded with Polonium alpha particles) by Irene Curie and J. F. Joliot, Paris.

 

1934   (Mar 12) Szilard applies for a patent, "Improvements in or Relating to the Transmutation of Chemical Elements," stating "In accordance with the present invention radio-active bodies are generated by bombarding suitable elements with neutrons... Such uncharged nuclei penetrate even substances containing the heavier elements without ionization losses and cause the formation of radio-active substances."

 

1934   (June 28 & July 4) Szilard amends his patent to add "the liberation of nuclear energy for power production and other purposes through nuclear transmutation." He hypothesizes, "a chain reaction in which particles which carry no positive charge and the mass of which is approximately equal to the proton mass or a multiple thereof (i.e. neutrons) form the links of the chain." He describes the concept of critical mass and of reflecting neutrons back into the mass. Further, "if the thickness is larger than the critical value... I can produce an explosion."

 

1934   (July 4) Marie Curie (born Nov 7, 1867) dies in Sancellemoz, France. The disease is aplastic pernicious anemia of rapid, feverish development.

 

1934   Fermi mistaken reports new element after bombarding uranium with neutrons. Ida Noddack suggests Fermi split the atom; this is ignored.

 

1934   Evans at MIT starts whole body counting.

 

1934   Production and use of radiosodium.

 

1934   "Tolerance Dose" of 0.1 R/day, measured in air, recommended by Advisory Committee on X-ray and Radium Protection.

 

1934   "Tolerance Dose" of 0.2 R/day, measured at the surface of the body, recommended by the International Committee on X-ray and Radium Protection.

 

1934   Enrico Fermi works out theory for beta minus decay.

 

1934   H. Urey discovers deuterium.

 

1934-1939  Measurements begin on radium content of natural waters.

 

1935   G. von Hevesy performs first radioisotope tracer studies using P-32 to measure water turnover rates in goldfish.

 

1935   Hans Bethe reports new ideas on the prospect of capture by the uranium nucleus of a neutron slowed by collision with hydrogen. 

 

1935   Neils Bohr conceives the "water droplet" model of the nucleus. 

 

1935   Irene and Frederic Joliot-Curie win the Nobel Prize in Physics.

 

1935   Compton and Allison state, "Though it is usually employed to give only qualitative results, the photographic plate can also be adapted to precise quantitative comparisons of x-ray intensities."

 

1935   Yukawa predicts the existence of mesons, reponsible for the short-range nuclear force.

 

1936   Bragg-Gray principle of charged particle radiation interaction with matter formed. Louis Harold Gray (1905-1965), student of Rutherford,  illustrates the principle first stated by Bragg in 1912.

 

1936   Victor Hess receives Nobel Prize for cosmic rays.

 

1936   First use of radioisotopes in therapy by John Lawrence (Berkeley); produced in 37 inch cyclotron; P-32 used on polycythemia vera.

 

1936   H. Yukawa and S. Sakata (Japan) predict electron capture process to compete with positron emission.

 

1936-1940  Use of radioiodine from MIT cyclotron. Patients at Mass. Gen. Hosp.

 

1936-1941  Rat work at MIT on radium but rats more resistant than man to radium effect.

 

1937   (Oct 19) Sir Ernest Rutherford (born 1871) dies, his ashes are placed in a corner of Westminster Abbey next to the grave of Isaac Newton.

 

1937   Lauritsen electroscope used to measure dose.

 

1937   Extrapolation chamber invented by Failla.

 

1937   Technetium discovered by Carlo Perrier and Emillo Segre (Italy).

 

1937   Mesons found in cosmic rays.

 

1938   (Dec) Nobel Prize awarded to Enrico Fermi (Italy) for his work on transuranics. The Fermi family (Laura, Enrico's wife, is Jewish) escapes from Italian Nazi persecution to New York.

 

1938   Electron capture radionuclides discovered by L. W. Alvarez (USA).

 

1938   Tritium discovery by Alvarez & Cornog; produced in accelerators.

 

1938   Hahn and Strassman split the atom repeating Fermi's work.

 

1939   (Jan 6) Hahn and Strassman's experimental results of fissioning uranium published in "Die Naturwissenschaften."

 

1939   (Jan 13) Frisch offers experimental proof of fission in a Geiger counter.

 

1939   (Jan 26) Fermi announces uranium releases a few neutrons on splitting. He speculates upon the possibility of a chain reaction.

 

1939   (March 3) Szilard and Zinn prove possibility of chain reaction by performing experiment in Pupin Hall, Columbia University which shows many neutrons are released during fission of uranium.

 

1939   (March 16) Hitler annexes Czechoslovakia, richest known source of uranium.

 

1939   (April 29) First official conference on fission is held in Berlin Germany by the Reich Ministry of Education.

 

1939   (April) The Joliot-Curies publish a report confirming Szilard and Zinn's finding of neutrons released by uranium fission.

 

1939   (April) Uranverein ("uranium club") founded in Berlin to do work on uranium fission.

 

1939   (Aug 2) Einstein signs letter, drafted by Leo Szilard and Eugene Wigner, to Roosevelt alerting him to the feasibility of building an atomic bomb and the threat of Germany building one.

 

1939   (Sept 3) Germany declares war on Great Britain.

 

1939   (Oct 21) Uranium Committee, appointed by Roosevelt, holds first meeting.

 

1939   Igor Kurchatov alerts the USSR government of the military significance of nuclear fission.

 

1939   Correct description of phenomena of nuclear fission by Meitner and Frisch (Germany).

 

1939   Enrico Fermi patents first reactor (conceptual plans).

 

1939   Binary scaler introduced as auxiliary pulse-counting equipment.

 

1939   More useful count rate meter developed.

 

1939   Francium discovered by Marguerite Duray (France).

 

1939   Canadian ore used in first atomic chain reaction experiment.

 

1940   (Feb 20) The German physicist Werner Heisenberg sends a secret report to the Army Weapons Bureau "On the Possibility of Technical Energy Production from Uranium Splitting. II."

 

1940   (July 15) Kerst operates first betatron.

 

1940   (Nov 8) First contract is signed with Columbia University to develop bomb material.

 

1940   Neptunium-239 discovered by E.M. MacMillan and P.H. Abelson (United States) at Berkeley. 

 

1940   George Flerov of the USSR discovers the spontaneous fission of uranium.

 

1940   Photomultiplier tube is developed by Larson and Salinger which makes scintillation radiation detectors much more useable.

 

1940   Astatine discovered by D.R. Corson, K.R. MacKenzie, and E. Segre (United States).

 

1940s  Enormous strides in ion chambers, vacuum tube electrometers, improved G-M tubes, pulse counting, discriminators, linear amplifiers, autoradiography, etc., taken under Manhattan Engineering District (MED) auspices.

 

1940   Radiation pneumonitis is described by Warren & Gates.

 

1940   Joseph John Thomson dies.

 

1940   Port Radium closes.

 

1940   Louis Harold Gray describes an energy unit - “that amount of neutron radiation which produces an increment of energy in unit volume of tissue equal to the increment of energy produced in unit volume of water by one röntgen of radiation”

 

1941   (Feb 25) Plutonium 238 isolated by G.T. Seaborg, J.W. Kennedy, E.M. MacMillan, and A.C. Wohl (United States) at Berkeley from products of neptunium decay. Seaborg and MacMillan win Nobel Prize in 1951 for this work.

 

1941   (Jun 28) Office of Scientific Research and Development is established under the direction of Vannevar Bush, to develop atomic energy.

 

1941   (Sept 18) Werner Heisenberg meets with Neils Bohr to try to convince Bohr and the Western Allies that atomic bomb production is unfeasible and should be stopped. Bohr is unconvinced and suspects Heisenberg's, now working for the Nazis, motives.

 

1941   (Sept) Enrico Fermi suggests to Edward Teller that an atomic bomb might heat deuterium sufficiently to create a full-scale thermonuclear reaction.

 

1941   (Oct 9) President Roosevelt decides to proceed with development of an atomic weapon after a meeting in which he is informed of its feasibility.

 

1941   (Dec 6) The day before the bombing of Pearl Harbor, President Roosevelt authorizes the Manhattan Engineering District. The secret U.S. project to build an atomic bomb, later to be called the Manhattan Project, is put under the direction of the Office of Scientific Research and Development.

 

1941   Max Permissible Body Burden set at 0.1 uCi for radium recommended by Advisory Committee on X-ray and Radium Protection based on radium dial painters.

 

1941   First standard for radon (10-11 Ci/l), Evans and Goodman National Bureau of Standards report.

 

1941   Pecher (Berkeley) finds that radiostrontium behaves like calcium and deposits in bone.

 

1941   Port Radium on Great Bear Lake in Canada reopens for war effort, as world's first uranium mine.

 

1941   On the initiative of Rolf Sievert, the government passes Sweden's first radiation protection law. Sievert helps standardize radiation doses to patients in hospitals and later in all workers.

 

WW 2   Animal work at U. of Rochester on rat with radium excretion.

 

1942   (Jan 24) A. H. Compton, chairman of the Physics Department at University of Chicago, announces his decision to site the first self-sustaining chain reaction at University of Chicago. This is over the objections of Szilard (Columbia U.) and Lawrence (Berkeley).

 

1942   (June 23) Werner Heisenberg's fourth experimental atomic pile, the L-IV, explodes spewing burning particles of uranium twenty feet in the air and catching the lab on fire. Heisenberg and Robert Doepel are nearly killed.

 

1942   (Aug 25) Entire world's supply of plutonium spilled and recovered from soggy copy of Chicago Tribune (Met Lab).

 

1942   (Sept 23) Colonel Leslie Groves is promoted to Brigadier-General and put in charge of the Manhattan Project. He recruits J. Robert Oppenheimer as Scientific Director.

 

1942   (Nov 16) Construction begins on Chicago Pile 1 (CP-1).

 

1942   (Nov 16) Groves and Oppenheimer select the site of the boys' school Los Alamos in New Mexico for the project. Oppenheimer tours the United States recruiting top scientists and persuading them to move to New Mexico. Edward Teller is among the first group of 100 to accept.

 

1942   (Dec 2) First sustained and controlled chain reaction in an atomic pile at University of Chicago’s CP-1. Reactor is graphite moderated. Fermi oversees design and building.  Fission products expected. Arthur Compton sends message to James Conant: “The Italian navigator has arrived at the shores of the new world and found the natives were friendly. It is a smaller world than he believed.”

 

1942   Beginning of biomed work at Chicago's Michael Reese Hospital on uranium (cells & whole organism).

 

1942   United States government orders 60 tonnes of uranium from Port Radium mine in Canada. Canadian government secretly begins to buy out mine. Dene work as coolies.

 

1942-1943  Concern develops at Metallurgical Laboratory (Chicago) about potential hazards of radioxenon & I-131 and fission products.

 

1942-1945  Concern over possible use of fission products in radiological warfare leads to Projects Peppermint and Gabriel (secret study on fallout effects).

 

1943   (Apr 1) The security gates begin operating at Oak Ridge, TN.

 

1943   (Apr) Ground broken for Hanford reactors, built to produce plutonium for Nagasaki bomb.

 

1943   (Apr) Thirty scientists assemble at Los Alamos, New Mexico for an introductory series of lectures on the theory and practicalities of designing and building an atomic bomb using uranium-235 or plutonium-239.

 

1943   (May 5) The Military Policy Committee of Manhattan Project developes the idea to use the atomic bomb on Japan rather than on Germany. The committee is chaired by General Leslie Groves

 

1943   (Nov 4) Oak Ridge X-10 Clinton reactor goes into operation at Oak Ridge; first to generate electricity with a model steam engine.

 

1943   Uranium toxicology studies at U. of Rochester.

 

1943   L.D. Marinelli of the Sloan-Kettering Institute in New York invents a beaker that has an open tube in the center to increase the efficiency of a GM counter detecting levels of I-131.

 

1943-1947  Polonium injected into incurable patients at Rochester, NY. Potential doses greater than occupational limits.

 

1944   (Mar 13) Barely sixteen months after the feasibility of achieving a self-sustaining nuclear chain reaction was established by Enrico Fermi  in Chicago -- a tightly held sec