whit3rd wrote:
On Tuesday, May 1, 2012 3:27:46 PM UTC-7, Jim Yanik wrote:
(Samuel M. Goldwasser) wrote in
:
Robert Macy writes:
On May 1, 5:25 am, Robert Macy wrote:
On May 1, 2:47 am, Jeff Urban wrote:
...snip...
Why the hell didn't they just go with electrostatic deflection
like in a scope ?
I fail to see how a "faster" E-beam will bend more under magnetic
fields,but not under electrostatic fields.
The transverse momentum you get from electrostatic deflection is
proportional to deflection plate voltage. The longitudinal momentum is
proportional to accelerating voltage (for color phosphors, 25 kV typical).
So, tangent of deflection angle is at most Vdeflection/Vacceleration.
Even infinite deflection voltage only gets 90 degrees deflection.
For magnetic deflection, the beam acquires a curvature proportional to B field;
the deflection angle can be anything you want. When it gets to 360 degrees,
your tube becomes a 'cyclotron'. I've seen multigigavolt beams doing
loops, at near the speed of light, for hours. You can't do that with electrostatic
deflection.
you can get any deflection you want, no limit
Also, electrostatic deflection defocuses and aberrates the beam, whereas
magnetic doesn't.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net