New gun fires pellets 10 times faster than bullet

A gun that fires coin-size pellets at speeds of 72,000 km per hour, 10 times faster than a speeding bullet, has been developed in the United States.

The gun, named ``Z accelerator,`` could fire a pellet from Seoul to Pusan in 22 seconds, or from London to New York in four and a half minutes. It is outpaced only by a nuclear explosion, the Daily Telegraph of Britain reported Tuesday.

Dr. Marcus Knudson at Sandia National Laboratories, a U.S. nuclear laboratory, who developed the ``fastest gun in the world,`` said that a more mobile version would be a ``hyper velocity`` weapon, piercing thicker armor than any used in battle. He said that the aluminum plates the gun fires move so fast that air resistance turns them to liquid, heating them to 2,700 degrees C, forcing him to look at other materials, such as titanium and cooper, the British daily reported.

The weapon has been used only to examine the impact of high-velocity projectiles over a distance of a few feet. But the technology is being considered as an alternative to launching spacecraft, the daily said. The accelerator`s vacuum chamber is the most powerful producer of electrical discharge on Earth. It uses 20,000 amps to develop a magnetic field that accelerates pellets up to 45,000 mph in 200 billionths of a second, three times faster than the speed needed to escape Earth`s gravitational pull, the paper reported.

Lee Jong-Hoon taylor55@donga.com