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alternating current amount amperes angle anode apparatus atoms beam beetles bombardment bulb cathode rays cent circuit coil connected constant Coolidge Coolidge tube copper crystal cube curve cylinder developed diameter diaphragm direct current discharge current distance dose effect electric electron emission energy input equation experimental experiments exposure filament filament temperature fluorescence focal spot given gives glass heat high tension hooded target hot cathode inches increase intensity inverse ionization ionization chamber kenotron lamp lattice length lines measured mechanical rectifier melting metal method milliamperes molybdenum obtained operation ordinary outfit penetrating photographic plate planes platinum portable positive ions possible potential produced pump radiator tube radiographic rectifier roentgen rays Roentgen tube roentgenogram secondary shown in Fig shows solid tungsten target space charge spark gap spectrum standard tube surface thermionic current thick transformer tungsten type of tube vacuum vapor volts wave wave-length wire X-ray tube
Page 167 - Abstract of a paper presented at the Washington meeting of the Physical Society, April 24-25, 1908.
Page 114 - However, the results of tests which entirely disprove this view of the phenomenon are given in the following table. The first column gives the number of the experiment, the second...
Page 11 - the large currents hitherto obtained with heated carbon cannot be ascribed to the emission of electrons from carbon itself, but that they are probably due to some reaction at high temperatures between the carbon, or contained impurities, and the surrounding gases, which involves the emission of electrons.
Page 244 - One-half of each face of the samples was machined off, so that half the length of the weld was between flat, parallel faces; the other half was left under the original rough surfaces. As a result, one-half of each sample was l/2 inch thick and the other half was about ? g inch thick.
Page 243 - From the data at hand it is easily possible by well-known means to construct formulas for computing the exposure necessary for radiographing steel at various spark gaps. Let Qo be the quantity of X-rays impinging on the steel during the exposure. Let Q be the quantity of the rays which pass through the steel. Let x be the thickness of the steel. Let X be the coefficient of absorption, and Let e be the base of natural logarithms.
Page 49 - If the temperature of the filament is low, only a small number of electrons escape from it and, consequently, only a small discharge current (the saturation current) can be sent through the tube. Increasing the impressed voltage above that needed for this current value causes no further increase in current. It simply increases the velocity of the cathode rays and hence the penetrating power of the Rontgen rays.
Page 190 - Its unit of structure is a cube with an atom at each corner and one in the center of each face. It may be formed by the superposition of four simple cubic lattices with construction points
Page 210 - ... every crystalline substance gives a pattern ; that the same substance always gives the same pattern ; and that in a mixture of substances each produces its pattern independently of the others, so that the photograph obtained with a mixture is the superimposed sum of the photographs that would be obtained by exposing each of the components separately for the same length of time. This law applies quantitatively to the intensities of the lines, as well as to their positions, so that the method is...