File:Crookes x-ray apparatus.png
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Summary
| Description |
English: A medical Crookes x-ray machine, wall mounted, from around 1910. This used a first generation cold cathode x-ray tube (left) invented by William Crookes, mounted on an adjustable rack. The earliest type of x-ray tube, the Crookes tube did not have a heated filament to generate electrons like modern x-ray tubes, but instead generated them by ionization of residual gas in the tube by a high voltage. It radiates x-rays downward, through an aperture in the mounting plate. The high potential of 10 - 80 kV for the tube was generated by an induction coil (top). The primary current for the coil was provided by an adjustable power supply (right). In order to create the abrupt flux changes the coil needed to operate the primary current was repeatedly broken by an electrolytic (Wehnelt) interrupter (bottom) invented by Arthur Wehnelt in 1899. This device consisted of a fine short platinum needle anode and a lead plate cathode, immersed in a jar of dilute nitric or sulfuric acid. When the primary current passed through the device, hydrogen bubbles formed on the needle and interrupted the currenf flow randomly thousands of times per second. Each "break" in the current created a pulse of high voltage from the coil. |
| Date | |
| Source | Retrieved 11 November 2013 from Sinclair Tousey 1921 Medical Electricity, Röntgen Rays and Radium, 3rd Ed., W. B. Saunders Co., Philadelphia, p. 719, fig. 457 on Google Books |
| Author | Sinclair Tousey |
Licensing
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This media file is in the public domain in the United States. This applies to U.S. works where the copyright has expired, often because its first publication occurred prior to January 1, 1929, and if not then due to lack of notice or renewal. See this page for further explanation.
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This image might not be in the public domain outside of the United States; this especially applies in the countries and areas that do not apply the rule of the shorter term for US works, such as Canada, Mainland China (not Hong Kong or Macao), Germany, Mexico, and Switzerland. The creator and year of publication are essential information and must be provided. See Wikipedia:Public domain and Wikipedia:Copyrights for more details.
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| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 03:55, 14 November 2013 | | 579 × 712 (44 KB) | Chetvorno | User created page with UploadWizard |
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