Fusion shielding and particle acceleration

[T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden)]

To Kelly,

>>Does anyone know how and if this problem can be solved?
>
>We know what the voltage evergy of the particals are 12-20 Mev.  So if we
>can keep up a higher charge...

I think that 20 Mev is not too bad.

>??  The fusion process in question doesn't relase photons.  The particals
>it does release have defined energies/speeds.

Yes, I assume you are right.

>Since we want to (as far as
>I remember the question) get the particals going faster.  Holding them in a
>bottle isn't going to help.  It presumably would slow them down, unless we
>add more energy to the bottle.

Yes, I hadn't done any calculations yet, so didn't know if we had to
accelerate them or decelerate them. So indeed we need to increase the
pressure in the bottle, the energy comes from the ongoing fusion process.

>With a normal rocket or jet you can boost presure because the material can
>be forced through a choke where higher back presure accelerates it.  The
>pressure in this case however would need to be maintained by a magnetic or
>electric field powered externally.  This does not appear to be practical.

Assuming v = 0.085c = 8.75E7 m/s the kinetic energy in Joules = 0.5*m*v^2
Assuming we are talking about 4He the mass = 4*1.66E-27 = 2.66E-26 kg
That gives E = 0.5*(2.66E-26)*(8.75E7)^2 = 1E-10 Joule
Converting to electron volts: 1E-10/1.6E-19=6.35E8 eV or 635 MeV

That's about 30 times higher than we need for a minimum (shielding the
engine itself). I think this is doable, maybe not practical, but either is
flying to the stars.

Timothy