Dynamic Young's moduli of tungsten and tantalum at high temperature and stress

Recently reported results of the long lifetime of the tungsten samples under high temperature and high stress conditions expected in the Neutrino Factory target have strengthened the case for a solid target option for the Neutrino Factory. In order to study in more detail the behaviour of the material properties of tungsten, a dynamic method has been used for measurement of Young's modulus at high stress, high-strain-rates (>1000 s^-1) and very high temperatures (up to 2650 °C). The method is based on measurements of the surface vibration of thin wires, stressed by a pulsed current, using a Laser Doppler Vibrometer. The measured characteristic frequencies under the thermal excitation have been used to obtain Young's modulus as a function of applied stress and temperature. The same procedure has been used to measure Young's modulus of tantalum up to 2500 °C.