X-rays simply explained - a handbook on the theory and practice of radiography (1903) (14735041426)

Identifier: xrayssimplyexpla00howg (find matches)

Title: X-rays simply explained : a handbook on the theory and practice of radiography

Year: 1903 (1900s)

Authors: Howgrave-Graham, Robert Pickersgill, 1880-

Subjects: X-rays Cathode rays X-rays Fluorescence X-Rays Fluorescence

Publisher: London : Percival Marshall & Co

Contributing Library: Francis A. Countway Library of Medicine

Digitizing Sponsor: Open Knowledge Commons and Harvard Medical School

Text Appearing Before Image:

r is generally credited with thefirst use of the focus tube in England at any rate,and it is usually known in this country by hisname. It is illustrated in fig. 5, Plate I., where K is aconcave kathode of aluminium which directs the tor-rent of radiant matter to a concentrated focal point onthe anode or antikathode A (see Chapter on X-rayBulbs). At this point of impact on the moleculartarget the X-rays are abundantly generated, and asthe target is of platinum it is not only enabled tostand any heat developed, but it also allows no pene-tration of the X-rays to its reverse face! The rays which are generated at the point ofimpact on A proceed radially outwards in straightlines in all directions, and as A is placed at an angleof 45 , with the axis of the tube, the rays pass out iMli.Y BXPLAINED. through ili ite to i he cent re of the plate without encountering any considerable opposition. by the dol!«•! lines the direction o!: ream, and by i he dot -and-dash linesilif path of tin Ron!

Text Appearing After Image:

■ft///! lll\$M^> / //HTTTV.\\\\\\\\ ///•/•, • \\V\W\ / / / l \ \ \ Fig. S.—Directions of the kathode stream (dotted) and X-rayand dash) produced in -\ focus fcul—The X-rays pass through th< scupied by the kathode .in and have only been omitted there to avoid confusion.) Aa ili« latter pass out through the glass they pro-duce fluorescence, usually of a canary-yellow or apple-in colour which varies according to the material of the flass and the degree of exhaustion. It is d bright, and occurs exactly over the area HISTORICAL A\i» EXPLANATORY. 41 which Is exposed to the Rontgen rays. The resultsobtained with the focus tube accord with what onewould naturally expecl when the source of thealmost a point: radiographic and screen effects arethereby rendered enormously Bharper and moredetailed without the necessity of working with thetube at some distance from the plate. A full accountof different types of tube is given below, hut a shortdescription (due to Mr J. H. < S

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1903

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