Comparing the adiabatic and isothermal pressure dependence of the index of refraction in a drop-weight apparatus
Oliver Slanina, S. Quabis, S. Derksen, Jörg Herbst, R. Wynands
Abstract
Abstract We have investigated the difference between adiabatic and isothermal compression of liquids by an impacting weight, as observed in the resulting change to the index of refraction. The liquids examined were sebacate, glycerol, and water. For practical reasons, sebacate is best suited for the use of a drop-weight apparatus as a metrologically traceable calibration facility for dynamic pressure. We find that its optical properties under adiabatic and isothermal compression can be converted into each other using literature values of its thermodynamic properties. Care has to be taken to avoid cavitation-like effects, an observation that might need to be taken into account for other methods of generating short pressure pulses in the hundreds-of-MPa range.