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Old 09-27-2009, 03:18 PM
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jeyurkon jeyurkon is offline
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Quote:
Originally Posted by old_coot88 View Post
Actually the beam is under constant acceleration from the time it leaves the gun till it hits the screen. The higher the HV, the higher the acceleration and the higher the final velocity. I dunno what the final velocity is, but it's really honkin' on.
Bill(oc)
That's partially true. If you look at the construction of CRT you'll notice that the aquadag, which is connected to the HV, extends back into the neck of the CRT. There are additional electrodes that we don't always think about. These are acceleration electrodes. The aquadag connects to the last electrode and the electrons reach their final velocity as they pass this electrode which happens before the beam passes the yoke.

While it may seem odd, the region past this last electrode inside the bell region is basically field free because it is all at the same potential.

John
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