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A beam of cathode rays being bent by a magnetic field. Cathode rays are normally invisible; the path of this beam is revealed by having it strike a card with a fluorescent coating. By the 1870s, British physicist William Crookes and others were able to evacuate tubes to a lower pressure, below 10 −6 atm. These were called Crookes tubes.
The cathode-ray tube by which J. J. Thomson demonstrated that cathode rays could be deflected by a magnetic field, and that their negative charge was not a separate phenomenon While supporters of the aetherial theory accepted the possibility that negatively charged particles are produced in Crookes tubes , [ citation needed ] they believed that ...
Crookes X-ray tube from around 1910 Another Crookes x-ray tube. The device attached to the neck of the tube (right) is an "osmotic softener". When the voltage applied to a Crookes tube is high enough, around 5,000 volts or greater, [16] it can accelerate the electrons to a high enough velocity to create X-rays when they hit the anode or the glass wall of the tube.
Walter Kaufmann began to experiment with beta rays using a device similar to a cathode ray tube, where the source of the electrons was the decay of radium that was placed in an evacuated container. (See Fig. 1) Such rays emitted from radium were called "Becquerel rays" at that time.
Julius Plücker (16 June 1801 – 22 May 1868) was a German mathematician and physicist.He made fundamental contributions to the field of analytical geometry and was a pioneer in the investigations of cathode rays that led eventually to the discovery of the electron.
In 1947, the cathode-ray tube amusement device, the earliest known interactive electronic game as well as the first to incorporate a cathode-ray tube screen, was created. [ 34 ] From 1949 to the early 1960s, there was a shift from circular CRTs to rectangular CRTs, although the first rectangular CRTs were made in 1938 by Telefunken.
The first attempt to measure the mass-to-charge ratio of cathode ray particles, assuming them to be ions, was made in 1884-1890 by German-born British physicist Arthur Schuster. He put an upper limit of 10^10 coul/kg, [5] but even that resulted in much greater value than expected, so little credence was given to his calculations at the time.
He believed the rays to consist of streams of particles of ordinary molecular magnitude. It remained for Sir J. J. Thomson to expound on the subatomic nature of cathode rays (consisting of streams of negative electrons [27]). Nevertheless, Crookes's experimental work in this field was the foundation of discoveries which eventually changed the ...