Compact flash X-ray sources and their applications

Abstract

Compact flash X-ray machines are opening up extended fields of applications. X-ray diodes driven by repetitive small size pulsers have been shown able to deliver high dose rates of X-rays in pulses of nanosecond to microsecond duration. Improvements have been carried out on the lifetime of the diodes and reliability of the systems to allow operation at constant emitted dose over long periods of time. After a brief review of recent developments, described here, in more details, is the progress obtained at the GREMI laboratory in the development of true table-top flash X-ray sources producing strong X-ray doses in nanosecond pulses at a high repetition rate (50 Hz). Doses up to 2 R (5.2 × 10 −4 C/kg), measured at the output window, of X-rays between 5 and 200 keV can be generated from either a linear source (up to 10 cm long) or from a focal spot of less than 300 μm in diameter depending on the electrode configuration. Of the numerous applications of compact flash X-ray sources, an example is given of the use of these devices for the excitation of high pressure gas samples, realized at GREMI. Such an energetic excitation leads to important populations of highly excited ionic species.