[ExI] Physical limits of electromagnetic launchers

[Jeff Davis]

Anders, Spike,

Maybe I'm wrong, but I think you misinterpreted Kelly's question.  In
referencing the particle acceleration method, it seemed to me he was
talking about the circular track configuration, not the charged
particle method of acceleration.

So could you try again, dispensing with the electric charge business
and just going with maglev or something similar.  I'm visualizing a
big ring in the tradition of "Ringworld", spinning just fast enough to
stabilize against its own gravity, and sans any central star.

Best, Jeff Davis

                 "Everything's hard till you know how to do it."
                                               Ray Charles

On Sat, Jun 2, 2012 at 2:35 PM, spike <spike66 at att.net> wrote:
>
>>... 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
>
>
>
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