Radar System Engineering

332 THE MAGNETRON AND THE PULSER [SEC. 10.3
alone ;itisuO = eH/m. Although theangular velocity ofthisrO rotation
is constant, the magnitude of TOdepends on the initial kinetic energy of
the electron and may vary for different electrons. The maximum distanceany
electron canproceed toward the anode (Ro + TO)in the absence
of r-f oscillations is fixed by the ratio E/H, and for good operating conditions
is made to be about half of the way from
E
cathode to anode.
The above description is exact only for the
v
Hev ~ #’J-
case of small TO (and a particular form of
c
~>& radial field). The picture is certain] y correct
H in a qualitative way and this description of the
“=~c
H
electron motion may be used in an explanation
of the interaction of the electrons with the
“ Et/H, the deflection will
be in the direction of the magnetic force. The deflection that an electron
suffers in this example when speeded up or slowed down thus corresponds
to what happens in a magnetron and it is significant that the operating
conditions are ones for which v = Et/H. This example is given only to
illustrate the complex electronics of these tubes and is obviously inaccurate
when applied to a magnetron because the electric field is not uniform
but has cylindrical symmetry and is further deformed by space
~uz
R
(1)