(x1,y1)

1
Determination of Radius of Curvature for
Horizontal Gun
We know two points on the electrons circular
orbit. Does that allow us to specify the curve
and determine Rc ? No (Think about this!) What
other information do we have? The
orbit is tangent at (x1,y1). This means the
center of the orbit is directly above (x1,y1).
Or with setting (x1,y1) as (0,0) the center is at
(0,Rc). Thus the equation of the orbit is
(x)2(y-Rc)2Rc2. Putting (x2,y2) into this
equation allows you to solve for Rc .
(x2,y2)
Position where e-beam strikes the phosphor.
Gun
(x1,y1)
Evacuated Bulb
Equation of a circle radius Rc with center at
(xc,yc) (x-xc)2(y-yc)2Rc2