Ask the Scholar

{
    "localId": "75730948",
    "label": "Proof, no date",
    "core": "doc",
    "dtoType": "document",
    "citationUrl": "https://catalog.archives.gov/id/75730948"
}

{
    "id": "75730948",
    "sourceUrl": "https://catalog.archives.gov/id/75730948",
    "contentType": "document",
    "title": "Proof, no date",
    "citationUrl": "https://catalog.archives.gov/id/75730948",
    "collections": [
        "Safety Light Collection",
        "Records Related to Radium Dial Painters"
    ],
    "iiifBase": "https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/SLC/Radium/SLC_0003754_Page_1.jpg",
    "thumbnailUrl": "https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/SLC/Radium/SLC_0003754_Page_1.jpg",
    "largeImageUrl": "https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/SLC/Radium/SLC_0003754_Page_1.jpg",
    "imageCount": 6,
    "hasImages": true,
    "source": "import",
    "hasTranscription": false
}

{
    "url": "https://catalog.archives.gov/id/75730948",
    "naId": 75730948,
    "levelOfDescription": "fileUnit",
    "recordType": "description",
    "ocrSource": "nara-archive"
}

{
    "seq": 6,
    "pageIndex": 0,
    "type": "document",
    "url": "https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/SLC/Radium/SLC_0003754.pdf",
    "mediaId": "cf8e4cfe6c736905",
    "ocrText": "Analysis of the Mineral Radium\nRadium, an alkaline earth metal, is one of the most important of\nthe naturally occurring radioactive elements, due to its relatively long life\nand to the fact that it is the parent of a series of radioactive elements which\nemit therapeutically and industrially useful radiations. Prior to the develop-\nment of the Atomic Energy Program, in which Uranium, the parent of the entire\nradioactive series of which radium is a member, plays an important part, radium\nwas without doubt the most important radioactive element. It was discovered\nby Professor and Madame Curie in Paris in 1898 as the result of an attempt to\nidentify the source of invisible radiations which it was noted were emitted by\ncertain minerals and which affected unexposed photographic plates.\nA radioactive element is one which possesses the chemical and\nphysical properties of a normal element, but differs from a normal stable\nelement in that a portion of the radioactive element is constantly undergoing\nchange, at a fixed rate, into other elements. This change is the result of the\nemission by the element of alpha, beta and gamma particles or rays. In order\nto understand this differentiation, a brief description of the structure of\nmatter is necessary.\nAll matter consists of one or more of ninety-six basic elements.\nPrior to the recent production of the elements Plutonium, Neptunium, Curium and\nAmericum under the Atomic Energy Program, ninety-two elements were known and\nof these radium was Number 88. The elements are known to consist of atoms and\nsince radioactive characteristics involve Atomic changes and Atomic changes produce\ndifferent elements a knowledge of Atomic structure is essential. The atom\nconsists basically of a compact central portion known as the Nucleus, composed\nof positively charged electrified particles called Protons and neutral particles\nconsisting of a closely bound positive and negative particle called Neutrons.\nRevolving about this central nucleus, and not unlike our own solar system, are\n2.\nElectrons, negatively charged particles equal in number to the Protons in the\nnucleus. The number of Protons and Neutrons is constant for the atoms of any\ngiven element, determines the characteristics of the element and any change in\nthis number or in the ratio of Neutrons to Protons produces a new element. The\nemission of charged particles from a radioactive element takes place from the\nnucleus of the atom and the atom from which the particle is emitted, therefore,\nbecomes an atom of a new element differing in characteristics and properties from\nthe parent element. An alpha particle, for example, is itself the nucleus of the\nhelium atom carrying a double charge and consists of two Protons and two Neutrons.\nIts emission from the nucleus of an atom produces a new atoms having two less\nProtons and two less Neutrons in the nucleus, and, therefore, also two less electrons\nin the orbits. The emission of a beta particle, which is a negatively charged\nparticle or electron, from the nucleus results in an increase in positive charges\nin the nucleus and again an atom of a new element is produced.\nWhen a radioactive element changes by emission of a particle to another\nelement which in turn changes by another particle emission and such a series of\nemissions and changes continues to produce a series of new elements, we have a\nso-called \"disintegration'series\". In such a series each element is the parent of\nthe one which follows and the daughter of the one which precedes it. Starting\nwith the element Radium, such a \"disintegration series\" through nine successive\nchanges ultimately results in a non-radioactive element Lead.\nRadium is in the so-called Uranium-Radium-Lead series, Uranium being\nthe parent of the entire series, and radium being the sixth member. The immediate\nparent of radium is Ionium and its daughter Radon, 8. radioactive gas. The entire\nseries may be represented as follows:\n3.\nUranium 1 alpha\nUranium X1 Beta\nUranium X2\nbeta\n4,670,000,000\n24.6 days\n1.15 min.\nyears\nUranium 11\nalpha\nIonium\nalpha\nRadium\nalpha\n2,000,000\n69,000 yrs.\n1690 years\nyears\nRadon alpha\nRadium A Alpha\nRadium B\nBeta\n3.85 days\n3 min.\n26.8 min.\nRadium C Beta & Gamma\nRadium\ncl\nAlpha\nRadium D\nBeta\n19.5 min.\n0.0001 sec.\n16 years\nF\nRadium E Beta\nRadium or\nAlpha\nLead\n5 days\nPolonium\n140 days\nThe designationsalpha, beta and gamma indicate the type of particle or\nray emission involved and the time intervals indicate the period required for one-\nhalf of any quantity of radioactive element initially present to be changed into\nthe next succeeding member of the series.\nThe minerals containing uranium, and, therefore, radium, are pitchblende\n(originally discovered in Czechoslovakia) and carnotite (in the western United States).\nIn 1920, a rich grade of pitchblende was found in the Belgian Congo and, in the\nearly 1930's, another was discovered in the Great Bear Lake region of Northwestern\nCanada. Since the early 1940's, virtually the entire world's supply of radium has\ncome from uranium ores mined in Canada and the Belgian Congo.\nThe actual weight of radium present in the ore is exceedingly small\nbeing present to the extent of one part radium for each 3,000,000 parts of\nUranium. The extraction process consists essentially of five major steps and\nthe chemical treatments involved are directed toward the extraction of the element\nBarium which is present in workable quantities, has chemical properties almost\nidentical to radium, and carries the radium with it throughout the initial processing.\n4.\nThe Uranium ore is treated with sulphuric acid which dissolves the Uranium.\nThe radium and barium in the form of insoluble sulphate salts are separated\nfrom the solution containing the Uranium; the insoluble radium and barium\nsulphate salts are treated to remove certain impurities; the sulphate salts are\nconverted to an acid soluble form and additional impurities are removed; the\nacid soluble salts are converted to the water soluble radium and barium chloride\nor bromide salts; the radium and barium are separated by a process of fractional\ncrystallization, the end product being a radium bromide salt of approximately\n90% - 98% purity.\nThe radium salt has now reached a stage where subdivision prior to\nfinal processing can be made. To determine the quantity of material present, a\nmeasurement of the intensity of the emitted radiations is required and the radium\nsalt must, therefore, be enclosed in a sealed tube or container to retain the\ndisintegration products of the radium. The unsealed radium preparation emits\nessentially only alpha radiation since the first disintegration product is\nradon, a gas, which is dissipated in the air. Determination of quantity by\nmeasurement of alpha radiation intensity is difficult and very inaccurate due to\nthe very slight penetrating power of this radiation. Alpha radiation will not\npenetrate a material even as thin as a cigarette paper and most of this radiation\nwould, therefore, be absorbed in the body of the radium salt itself and be\nunavailable for measurement. The salt is, therefore, enclosed in sealed tubes,\nthe radon retained and, after a lapse of time of approximately thirty days, to\npermit growth of disintegration products, quantity of radium present is determined\nby measurement of the intensity of gamma radiation emitted by Radium C.\nRadium salts (radium bromide, radium chloride, radium sulphate) have\nno industrial or therapeutic use. Quantities available are very small and the\ncost prohibitive. The value of radium is not in the radium or radium salt itself\n5.\nbut lies wholly in the radiations emitted. These discrete particles of matter,\nthe alpha and beta particles and the gamma radiation emitted in the course of\nthe series of disintegrations are the products used both industrially and\ntherapeutically. At the point where radium reaches the stage of a tubed salt,\nit first emerges as a form of radium which can be measured and is susceptible\nof being handled as an article of commerce, but, because of the inherent qualities\nof the radium which make it of any use, the final processing in fact begins.\nThe radium or radium salts must now be processed to a form which will\nmake available the specific radiation required. Depending upon the end use this\nprocessing may involve chemical processing, mechanical treatment or simply physical\ntransfer to special types of carriers, but one or more of these processes is always\ninvolved. The penetrating power of each of the radiations is different as is also\nthe effect produced and entirely different processing techniques are involved to\nutilize the radiations. Packaged in the form of hermetically sealed tubes, radium\nsalts are susceptible of handling without loss of the important radon and its\ndisintegration products, but have no industrial use. It is at this point that the\nfirst processing necessary to ultimate use begins. A glass or copper tube filled\nwith radium salts is not unlike a standing pine tree on the stump. It has value\nbut no usage until cut down, cut up into sawlogs, transported to a mill and\nultimately sawed and planed into the form of lumber."
}