If you think Superman is fast, talk to Marcus Knudsun. His "Z accelerator" uses a magnetic field to hurl tiny plates at speeds up to 20 km/sec. At 20 times faster than a bullet fired from a rifle, the tiny plates are fast enough to leave most superheroes in the dust and also help aerospace and telecommunications engineers simulate how space debris affects the metal skin of orbiting satellites and space observatories. Knudson is a physicist at Sandia National Labs who is researching how materials react to pressure and temperature. "The impact velocities of space debris can be quite high, on the order of 20 km/sec," says Knudson. Beyond 20 km/sec, the temperature of the aluminum plates reaches 2,500K and the plates melt. The propulsion technique that Knudson uses works by applying the Z accelerators at 20 million amps to produce an evolving magnetic field that expands in approximately 200 nsec, ultimately reaching several million atmospheres of pressure. The resulting expansion of the magnetic field propels the small plates, just as a surfboarder who catches a wave is propelled through space. "The amount of mass that is launched to high velocity is limited to a pellet weighing a couple hundred milligrams," Knudson says. "The technology will allow testing of debris shields, something that would be of interest to NASA and the communications industry," he explains. The technique is said to be the fastest, cheapest, and easiest way to determine how materials react to high pressures and temperature. For more information, contact Knudson at (505) 845-7796 or firstname.lastname@example.org.
Californiaís plan to mandate an electric vehicle market isnít the first such undertaking and certainly wonít be the last. But as the Golden State ratchets up for its next big step toward zero-emission vehicle status in 2018, it might be wise to consider a bit of history.
A customer who was thermal printing strip steel had a problem: When the strip's speed increased, the thermo printer would catch fire. When he set a flame to a piece of the strip, he couldn't get it to burn. What was the problem?