National Nuclear Security Administration

Meet a Machine: JASPER is 10x faster than a shooting bullet

May 1, 2017

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The Joint Actinide Shock Physics Experimental Research Facility at the Nevada National Security Site is a two-stage gas gun that uses compressed gas to fire a projectile down a vacuum tube at a sample of plutonium.

You wouldn’t expect scientists at the U.S. nuclear security enterprise to find an air rifle very useful. But the Joint Actinide Shock Physics Experimental Research Facility, or JASPER, at the Nevada National Security Site is a two-stage gas gun that uses compressed gas to fire a projectile down a vacuum tube at a sample of plutonium – like a super-duper-charged air rifle.

During a shot, a series of events sends a projectile down the 65-foot gas gun and through the barrel of the gun at 8 km per second. The projectile hits the plutonium target and creates a high pressure shockwave millions of times the atmospheric pressure at the Earth’s surface.  A diagnostic system detects the projectile impact and triggers measurements of the properties of the shocked plutonium. Confinement systems safely catch the projectile and protect workers.  

When researchers measure the way the shockwave produced from the impacting projectile affects the plutonium sample, the data refines NNSA scientists’ computer models to predict aging effects, performance, and the safety of stockpile nuclear weapons. The conditions created by the firing of the gas gun approximate those experienced in nuclear weapons without creating criticality.