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Re: [Phys-l] Am I missing something here?



At 02:58 PM 2/4/2008, you wrote:
"In 1898 Wien studied the canal rays discovered by Goldstein and
concluded that they were the positive equivalent of the negatively-
charged cathode rays. He measured their deviation by magnetic and
electric fields and concluded that they are composed of positively-
charged particles never heavier than electrons."

from the Nobel site.

bc thinks it [is] 'much' not 'never'.


I am tempted to agree. It was not so long ago that CRTs were fitted with an
'ion trap' to avoid burn spots on the phosphor face of the TV.

It is possible though, that Wien was studying some situation where
secondary electrons were emitted. It was not so unusual for example to
find cathode ray tubes whose screen was not connected to the final side anode
and its graphite coat. These tubes needed secondary electrons to travel back
from the screen.

Would an electron on the back path resemble a forward
positive electron from the directional effect of impressed fields?
But I am reaching...no doubt.



Brian Whatcott Altus OK Eureka!