Instead of being used to generate high velocity particles in a narrow cone, a Casaba Howitzer can be used as a nuclear version of modern HEAT rounds. A metal cone is partially melted and squeezed into a jet by the detonation of a nuclear shaped charge. The only requirement is that the energy deposited into the metal lining is not sufficient to vaporize it. It would achieve higher velocities by allowing it to vaporize, but would expand into uselessness, as any gas would. A 'direct' nuclear EFP, where the thermonuclear explosive is in contact with the metal cone to exploit the Munroe effect, produces a projectile with a velocity calculated by the Gurney equation: V = ( (2*Y*E)^0.5 )*(((1+2*M)^3 + 1)/(6*(1+M))^-0.5) V is the velocity achieved, in m/s. Y is the yield of the nuclear device, in joules. E is the efficiency is the device, about 0.85 for nuclear shaped charges. M is a ratio: explosive mass divided by projectile mass. In this case, explosive mass is the mass of the beryllium that absorbs the nuclear device's X-rays and converts them into thermal energy, thereby becoming a working fluid. 1kt NEFP Y is 0.1kt or 0.42TJ E is 0.85 M is 0.2, as recommended by the original Orion study V = 2619km/s

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