<s>
A	O
dynode	B-Algorithm
is	O
an	O
electrode	O
in	O
a	O
vacuum	O
tube	O
that	O
serves	O
as	O
an	O
electron	O
multiplier	O
through	O
secondary	O
emission	O
.	O
</s>
<s>
The	O
first	O
tube	O
to	O
incorporate	O
a	O
dynode	B-Algorithm
was	O
the	O
dynatron	O
,	O
an	O
ancestor	O
of	O
the	O
magnetron	B-Device
,	O
which	O
used	O
a	O
single	O
dynode	B-Algorithm
.	O
</s>
<s>
Photomultiplier	O
and	O
video	O
camera	O
tubes	O
generally	O
include	O
a	O
series	O
of	O
dynodes	B-Algorithm
,	O
each	O
at	O
a	O
more	O
positive	O
electrical	O
potential	O
than	O
its	O
predecessor	O
.	O
</s>
<s>
Secondary	O
emission	O
occurs	O
at	O
the	O
surface	O
of	O
each	O
dynode	B-Algorithm
.	O
</s>
<s>
The	O
electrons	O
emitted	O
from	O
the	O
cathode	O
are	O
accelerated	O
toward	O
the	O
first	O
dynode	B-Algorithm
,	O
which	O
is	O
maintained	O
90	O
to	O
100	O
V	O
positive	O
concerning	O
the	O
cathode	O
.	O
</s>
<s>
Each	O
accelerated	O
photoelectron	O
that	O
strikes	O
the	O
dynode	B-Algorithm
surface	O
produces	O
several	O
electrons	O
.	O
</s>
<s>
These	O
electrons	O
are	O
then	O
accelerated	O
toward	O
the	O
second	O
dynode	B-Algorithm
,	O
held	O
90	O
to	O
100	O
V	O
more	O
positive	O
than	O
the	O
first	O
dynode	B-Algorithm
.	O
</s>
<s>
Each	O
electron	O
that	O
strikes	O
the	O
surface	O
of	O
the	O
second	O
dynode	B-Algorithm
produces	O
several	O
more	O
electrons	O
,	O
which	O
are	O
then	O
accelerated	O
toward	O
the	O
third	O
dynode	B-Algorithm
,	O
and	O
so	O
on	O
.	O
</s>
<s>
By	O
the	O
time	O
this	O
process	O
has	O
been	O
repeated	O
at	O
each	O
of	O
the	O
dynodes	B-Algorithm
,	O
105	O
to	O
107	O
electrons	O
have	O
been	O
produced	O
for	O
each	O
incident	O
photon	O
,	O
dependent	O
on	O
the	O
number	O
of	O
dynodes	B-Algorithm
.	O
</s>
<s>
For	O
conventional	O
dynode	B-Algorithm
materials	O
,	O
such	O
as	O
BeO	O
and	O
MgO	O
,	O
a	O
multiplication	O
factor	O
of	O
10	O
can	O
normally	O
be	O
achieved	O
by	O
each	O
dynode	B-Algorithm
stage	O
.	O
</s>
<s>
The	O
dynode	B-Algorithm
takes	O
its	O
name	O
from	O
the	O
dynatron	O
.	O
</s>
<s>
Albert	O
Hull	O
did	O
not	O
use	O
the	O
term	O
dynode	B-Algorithm
in	O
his	O
1918	O
paper	O
on	O
the	O
dynatron	O
,	O
but	O
used	O
the	O
term	O
extensively	O
in	O
his	O
1922	O
paper	O
.	O
</s>
<s>
In	O
the	O
latter	O
paper	O
,	O
he	O
defined	O
a	O
dynode	B-Algorithm
as	O
a	O
"	O
plate	O
that	O
emits	O
impact	O
electrons	O
...	O
when	O
it	O
is	O
part	O
of	O
a	O
dynatron.	O
"	O
</s>
