Roentgens

Evaluation of results of those photos gives radiation source dimensions with area no more than Imm what defines high contrast of roentgen photos of flaw detected objeets. 

At betatron flaw detection not only roentgenography rate is of great meaning, but also the quality of roentgen photographs. 

Steel was used as the control object. During the experiments radiation energy, steel layer thickness, focal distance, roentgen films, screens were varied. Sensitivity was valued according to wire and groove standards. 

Exposures were detected at energies of 25 and 45 MeV for the home roentgen film types PT-1, PT-5 and import types D4, D7, Agfa-Gevaert , MX-5 Kodak . The lead strengthening screens were used for roentgen survey. Cassettes were loaded according to 2H3 scheme. In the experiments focal distances (F) came to 1.5, 2.0, and 3.0 m. 

In 1896, only a few months after Roentgen aimounced the observation of x-rays, Becquerel reported the additional observation of penetrating radiation emitted from certain natural materials, a phenomenon that Marie Curie would later name radioactivity. This phenomenon had a much less glamorous development. Over a three-year period, Becquerel pubHshed three articles, decided there was Htfle else to learn about it, and went on to the study... 

Ra.dia.tlon Units. Units in use for activity of a radionucHde, ie, the curie, the roentgen (exposure to x and gamma rays), the rad (absorbed dose), and the rem (dose equivalent), should eventually be replaced by the becquerel (Bq), coulomb per kilogram (C/kg), gray (Gy), and the sievert (Sv), respectively. 

X-rays were discovered by Wilhelm Roentgen in 1895. Soon after their discovery Roentgen used x-rays to image the bones in a human hand. The x-rays transmitted through the hand (phenomenon 1) were recorded on photographic film. The bones or other dense objects absorb x-rays more than do soft tissues or less dense materials (phenomenon 2). This method of imaging the internal stmcture of an object is known as x-ray radiography. 

The number of disintegrations per second gives no information about the radiation. The early measure of this was the Roentgen that measures the ionization density in ion chambers (Table 8.3-2). 

When log I/I0 is plotted against D, a straight line is obtained in a rather large region (4x 106 to 4x 107 roentgens) as in all the cases which will be handled here. No post effect was observed. Such a phenomenon has only been detected for CHI3 3S8 which will be studied in a next paragraph. 

C635C14(0H)2. The spectrum presents a doublet structure. The resonance line located at 36.744 Mc/sec was considered. The forty per cent dose is about 20.8x 108 roentgens.13... 

But Roentgen s achievements transcended mere discovery. He studied the properties of the new rays so well that he laid the foundations not only for important methods of x-ray detection (fluorescence of a phosphor, darkening of a photographic plate, ionization of a gas) and for radiography, but for the application of x-ray absorption to analytical cKemistry as well. 

The idea of using a hot cathode in a Roentgen tube was not new, but.. . the principle had never been... 

W. C. Roentgen s three great papers have been reprinted in Ann. Physik u. Chern., 64, 1-37 (1898), where they are more accessible than in the journals of first publication, there cited. The quotation is from page 9. 

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