Application of compact laser-driven accelerator X-ray sources for industrial imaging

X-rays generated by betatron oscillations of electrons in a laser-driven plasma accelerator were characterised and applied to imaging industrial samples. With a 125TW laser, a low divergence beam with 5.2±1.7 × 107photonsmrad−2 per pulse was produced with a synchrotron spectrum with a critical energy of 14.6±1.3keV. Radiographs were obtained of a metrology test sample, battery electrodes, and a damage site in a composite material. These results demonstrate the suitability of the source for non-destructive evaluation applications. The potential for industrial implementation of plasma accelerators is discussed

Investigation of low-temperature fixed points by an international star intercomparison of sealed triple-point cells

An overview of the results of an international star intercomparison of low-temperature fixed points is given. Between 1997 and 2005, 68 sealed triple-point cells (STPCs) of the twelve laboratories represented by the authors were investigated at PTB. The STPCs are used to realize the triple points of hydrogen, neon, oxygen and argon as defining fixed points of the International Temperature Scale of 1990, ITS-90. The melting curves (MCs) of all STPCs have been measured on the same experimental equipment, adhering strictly to a single measurement program. This protocol enables separation of the effects influencing the MCs and direct comparison of the thermal behaviour of the STPCs, which are quite different with respect to design, age, gas source and filling technology. In the paper, special emphasis is given to the spread of the liquidus-point temperatures and to the uncertainty of their determination. Connections between the star intercomparison and completed and ongoing international activities are also discussed