The American journal of roentgenology, radium therapy and nuclear medicine (1906) (14734500196)

Identifier: americanjournroen07ameruoft (find matches)
Title: The American journal of roentgenology, radium therapy and nuclear medicine
Year: 1906 (1900s)
Authors: American Radium Society American Roentgen Ray Society
Subjects: Radiotherapy X-rays
Publisher: Springfield, Ill. C.C. Thomas
Contributing Library: Gerstein - University of Toronto
Digitizing Sponsor: University of Toronto



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tube to be exhausted is sealeddirectly to the glass tube coming from theIi((uid air trap. It is supported inside of alarge oven, which is arranged with electricheaters for heating the tube during the firststage of the exhaust, and so constructed asto provide ample a-ray protection for theoperators (Fig. 9). The first operation in the exhaust consistsof heating the tube to about 400°C. forthree-quarters of an hour. This heating re-moves water-vapor, carbon dioxide andother gases from the glass and metal parts. After cooling, the tube is connected to an-t-ray machine and operated as an .r-raytube. For the early stages of the exhaust, a Manufacture of the Coolidge A-Ray Tube 259 machine is used which is so arranged that itoperates automatically, passing just enoughcurrent through the tube to drive out the gasat a rate at which it can be removed by theexhaust system. The final stages are carried
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Fig. 7. Glass-Blowing M.\chine. out on a regular interrupterless machine, andthe operation has to be very carefully regu-lated by trained operators. As the vacuumimproves, the potential applied to the tubeis constantly raised. The operation is con-tinued until all signs of gas, that is, appre-ciable green fluorescence in the bulb, havedisappeared and the tube is backing up a10 inch parallel spark gap and the anode isat an intense white heat. The whole opera-tion requires about one and a half to twohours time. The above description applies to the ex-haust of the Universal type of tube. Theanode in the radiator types of tube cannotbe heated as hot because of the low meltingpoint of copper. The exhaust is carried out with the tubes connected to high tensiontransformers without mechanical rectifiersand requires a considerably longer time thanthe Universal type. 4. TESTING Jr-RAY TUBES. A. Universal Type. When the exhaustof the tube is completed, it is sealed off fromthe exhaust system. Af