The most powerful X-ray pulse ever reported was generated at the SLAC National Accelerator Laboratory in California. Nearly a terawatt of power was packed into just 440 billionths of a second, or an attosecond. This is 1,000 times the average annual output of a nuclear power plant.
“In the short term, it’s going to be hard to do better than that,” says Agostino Marinelli who worked on this project at SLAC.
Source: www.newscientist.com