Cathode radiation

Kathoden-dichte, /. cathode density, -fiache, /. cathode surface, -licht, n. cathode glow, -niederschlag, m. cathode deposit, -raum, m. cathode space, space aroimd the cathode, -rdhre, /. cathode-ray tube, -strahl, m. cathode ray. -strahlenbiindel. n. cathode beam, -strahlrbhre, /. cathode-ray tube, -strahlimg. /. cathode radiation, -strom, m. cathode current, -zerstaubimg, /. cathode sputtering. 

The idea of indivisibility or indestructibility of the atom was disproved by Joseph J. Thomson, when he discovered the cathode radiation in 1897. He was able to prove that this radiation consisted of charged particles that originated from atoms. This meant that atoms could be cracked with the formation of the charged particles, which are now called electrons. 

The emission spectrum from a hollow cathode lamp includes, besides emission lines for the analyte, additional emission lines for impurities present in the metallic cathode and the filler gas. These additional lines serve as a potential source of stray radiation that may lead to an instrumental deviation from Beer s law. Normally the monochromator s slit width is set as wide as possible, improving the throughput of radiation, while being narrow enough to eliminate this source of stray radiation. 

The advantage of using a hollow cathode rather than a broad-band continuum is illustrated in Figure 3.20. By using a continuum, sensitivity would be lost because only a relatively small amount of radiation would be absorbed. 

Sodium nitrite has been synthesized by a number of chemical reactions involving the reduction of sodium nitrate [7631-99-4] NaNO. These include exposure to heat, light, and ionizing radiation (2), addition of lead metal to fused sodium nitrate at 400—450°C (2), reaction of the nitrate in the presence of sodium ferrate and nitric oxide at - 400° C (2), contacting molten sodium nitrate with hydrogen (7), and electrolytic reduction of sodium nitrate in a cell having a cation-exchange membrane, rhodium-plated titanium anode, and lead cathode (8). 

A role is also played by the temperature and frequency dependence of the photocurrent, the variable surface sensitivity at various parts of the cathode and the vector effect of polarized radiation [40]. All the detectors discussed below are electronic components whose electrical properties vary on irradiation. The effects depend on external (photocells, photomultipliers) or internal photo effects (photoelements, photodiodes). 

Electrical sources static electricity, electrical current, lightning, stray currents (radiofrequency electromagnetic radiation, overhead high voltage transmission lines, galvanic and cathodic protection stray currents)... 

Electrolytic separation of metals 508, 509 of cobalt and nickel, (cm) 533 with controlled cathode potential, 517, 518 see also under individual metals Electromagnetic radiation 646 Electron as standard reagent 535 Electron capture detector 242... 

Carbon, analysis, 217, 318, 319 Carbon brushes, examination by x-ray absorptiometry, 97 Cathode follower, 60 Cauchois arrangement, 119, 120, 123 Caustic circle, 119, 120 Cells for liquids, 191, 194 Cements, analysis in Applied Research Laboratories PXQ, 260, 261 Ceramics, analysis by x-ray emission spectrography, 222-224 Cerenkov radiation, 43 Cesium, determination by x-ray emission spectrography, 328 Characteristic-line generator of Eng-strom, 144... 

At the time that J. J. Thomson conducted his experiments on cathode rays, the nature of the electron was in doubt. Some considered it to be a form of radiation, like light others believed the electron to be a particle. Some of the observations made on cathode rays were used to advance one view or the other. Explain how each of the following properties of cathode rays supports either the wave or the particle model... 

Our experimental techniques have been described extensively in earlier papers (2, 13). The gamma ray irradiations were carried out in a 50,000-curie source located at the bottom of a pool. The photoionization experiments were carried out by krypton and argon resonance lamps of high purity. The krypton resonance lamp was provided with a CaF2 window which transmits only the 1236 A. (10 e.v.) line while the radiation from the argon resonance lamp passed through a thin ( 0.3 mm.) LiF window. In the latter case, the resonance lines at 1067 and 1048 A. are transmitted. The intensity of 1048-A. line was about 75% of that of the 1067-A. line. The number of ions produced in both the radiolysis and photoionization experiments was determined by measuring the saturation current across two electrodes. In the radiolysis, the outer wall of a cylindrical stainless steel reaction vessel served as a cathode while a centrally located rod was used as anode. The photoionization apparatus was provided with two parallel plate nickel electrodes which were located at equal distances from the window of the resonance lamp. 

Colloids of a-FejOj are made by hydrolysis of FeClj and subsequent dialysis of the sol. Polyvinyl alcohol is often used as a stabilizing agent. The band gap in Fe203 is 2.2 eV. In some of the studies on colloidal Fc203 free radicals were generated by ionizing radiation and electron transfer reactions with the colloidal particles investigated. Buxton et al. observed a cathodic dissolution of a-FCjOj in acidic... 

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