[ExI] Physical limits of electromagnetic launchers

[spike]

>... On Behalf Of Anders Sandberg
Subject: Re: [ExI] Physical limits of electromagnetic launchers

On 02/06/2012 19:53, Kelly Anderson wrote:
> If we take a lesson from the particle accelerator folks, can we run 
> them around a big circle speeding them up for a bit before going to 
> the long straight cannon? What point do you have to be at for the 
> sideways G forces to be too much?

>...Particle accelerators use charged particles held in place with a
magnetic field and accelerated using oscillating electical fields. So the
problem becomes whether one can charge up the payload enough to make it
couple well with the field, and how big the accelerator has to be...--
Anders Sandberg


Ja, and when you do the calculation of a circular accelerator, keep in mind
that any particle in a curved path is accelerated toward the center at
r*omega.  Since the payload is charged and is being accelerated, it emits
Bremsstrahlung radiation, and by conservation of momentum all that energy
being radiated away must go into the input side.  If the payload is anything
other than a proton or electron stream, we might imagine the radiated power
to be enormous.  

The proof is the coolest thing I ever saw: it brings in Maxwell's equations
and the Dirac equation to predict the radiated power.

A long time ago I thought of using a synchrotron to make a proton beam,
perhaps as a means of knocking out incoming nuclear weapons.  Of course it
has been a long time since I played with those equations.  WOW you guys are
making me think hard.

spike