Hydrodynamics

Simulation Experiments

Weapon simulation experiments aim to reproduce as much of the warhead as appropriate, using inert materials.

Two types of experiment are described here, Tamper Movement, and Core Punch trials.

Tamper Movement Experiments

A 'Tamper Movement' trial is a type of hydrodynamic trial used to measure the motion of a 'tamper' material as it implodes due to the detonation of explosives around it (Figure 1).

Figure 1.

Core Punch Experiments

In a ‘Core Punch’ experiment, a very short pulse (80 billionths of a second) of high energy X-rays is used to look inside the dynamic simulant warhead to determine interface positions and material spatial density distributions. We have the capability to take two images separated by few hundred billionths of a second.

Core punch radiography is compared with the more familiar medical radiography in Table 1.

Comparison of Medial and Core Punch Radiography

	Medical Radiography	Core Punch Radiography
Attenuation of object	10-20cm of water	10-20cm of Pb (1 photon in 100,000 gets through)
Velocity of object	Stationary	Several km/sec
X-ray machine dose	0.25 Rads	400 Rads
X-ray machine voltage	125,000 Volts	10,000,000 Volts
X-ray machine current	0.32 Amps	35,000 Amps (similar to a lightning bolt)

The extreme nature of weapon simulation experiments can be demonstrated by comparing photographs of the experimental facility before (Figure 2) and after (Figure 3) firing.

Figure 2.

Figure 3.