A team of researchers at Kyoto University, Japan have developed a portable X-ray device measuring only 3×5 cm. The device is powered by two D batteries and uses two tantalic-acid-lithium electrodes, which when subjected to electric current, affect electron emission from a gas within the device’s glass enclosure.
X-rays are routinely used in the elemental analysis of various samples, and the team, led by professor Jun Kawai, hopes that their device could be used with a portable X-ray detector to bring elemental analysis to the field.
Report in the Nikkei Business Daily: Kyoto Univ Develops Handheld X-Ray Device
(hat tip CrunchGear)
Researchers Develop Portable X-ray Device
October 13th, 2010 
Aaron Rulseh Radiology