Abstract
I HAVE had a focus-tube constructed, in which the distance between the electrodes can be varied, after Mr. Campbell Swinton's pattern, but in which the kathode is made the movable electrode, and the adjustment is made by magnetic control. This is effected by attaching a disc of soft iron to the slidingrod of the kathode. The advantage of this arrangement is that the kathode can be moved up to, or away from, the anode while the tube is working, so that the best effect can be at once obtained. The resistance is, as Mr. Swinton has pointed out, greater when the electrodes are close together than when they are far apart. The best fluorescent effects are, however, obtained when the electrodes are so close together (about one millimetre apart) that a very bright arcing discharge occurs between them. The screen is now lighted up much more brilliantly than when they are at any other distance apart. The very bright fluorescence is only obtained when the arcing discharge occurs. If the electrodes are brought any nearer together, the platinum anode becomes red-hot, the fluorescence fails, and the resistance of the tube increases very rapidly. I do not remember having seen this noted before.
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
TURNER, D. Röntgen Rays. Nature 56, 54 (1897). https://doi.org/10.1038/056054b0
Issue Date:
DOI: https://doi.org/10.1038/056054b0
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.