It seems 4HV.org has gone.  RIP.

anyone have any news about it?

thanks,
Robert.

I'm having fun building a multistage coil gun.   Using low voltage, and high current.

In reading some of the canon websites (eg. Barry's Coil Gun size - which is excellent, btw).  theres a lot of talk about determining energy from the capacitor, and comparing with the kinetic energy of the projectile to determine efficiency.

However, it occurred to me that it was more useful to look at the energy stored in the inductor, rather than the capacitor.  As its the device directly affecting the projectile.

Energy in an Inductor is

    E_L = 1/2 L I²

The inductance (L) can be measured, calculated etc.  and has a direct bearing on the construction of the coil.  For example, in a solenoid type coil:

    L = u N²A / l

Where A is the cross section area of the inductor, and l is the length.  Other formula exist for disk/pancake coils.

The current (I) can be measured too, and is more "important" as the energy is proportional to the square.  The field strength is proportional to current also:

    B = u N I / L

So my plan is to use super high current, several hundred to kilo Amps, in relatively low value inductors.   Switched with ganged MOSFETs.

I'm hoping this will prompt a discussion.
cheers!


*edited, based on Twospoons comments