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Summary
| Description |
English: Early Crookes x-ray tube from the Museum of Wilhelm Conrad Röntgen in Würzburg, Germany. These first generation 'cold cathode' x-ray tubes were used from the 1890s until about 1920. The electrode on the right was the concave cathode or negative electrode, which focused a beam of electrons on the angled platinum anode in the center of the bulb. When the electrons struck this they generated x-rays, which passed through the glass wall of the tube at top. The electrode to the left of the anode was called the auxiliary anode.
The curved tube attached just above the cathode is an 'osmotic softener' device to adjust the pressure in the tube. Crookes tubes required some gas in them to operate, but as time passed the gas was absorbed by the walls of the tube and the pressure dropped, requiring higher voltage across the tube which generated 'harder' x-rays, until eventually the tube stopped working. The softener consists of a tiny palladium tube, closed on the outer end, which projects through the glass wall of the tube. It is protected by a glass cap. When the pressure got too low, the cap was removed and a flame was played over the palladium tube. Hydrogen ions from the flame diffuse through the palladium into the tube, raising the pressure. For more information see Frederick F. Strong, (1908) High Frequency Currents, Rebman Co., New York, p.192-200 |
| Date | May 8th 2008 (see EXIF) |
| Source | my own camera |
| Author | me |
| Permission (Reusing this file) |
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Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled GNU Free Documentation License. |
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| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 22:08, 9 May 2008 | | 2,842 × 2,004 (2.08 MB) | Aida | {{Information |Description=Old X-ray tube from museum of Wilhelm Conrad Röntgen in Würzburg |Source=my own camera |Date=May 8th 2008 (see EXIF) |Author=me |Permission=Own work |other_versions= }} {{self|GFDL|cc-by-sa-3.0,2.5,2.0,1.0}} [[Category:X-ray |
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