Measuring Gr(?)neisen Parameter Of NaC1 By Double-Quick And Larger Range Compression

Gruneisen parameter γ is a very important parameter of condensed matters, which includes almost all information of the matter. The study of γ is very important for properties of thermodynamics, elasticity, non-syntony of the matter. It is a very difficult problem to aquire exact γ even though it has been studied with various theoretical and experimental methods for years, because the data obtained from theoretical model can' t be tested in experiment and the precision in the experiment is quite low.At first, this paper surveyed and analysized the former investigations of γ. Based on the existing problems in the study of Boehler, a double-quick and larger range compression technique is adopted in this experiment for measuring Grtlneisen parameter. It should be mentioned that the experiment is the first one to measure Grtlneisen parameter of NaCl using Bridgman anvils.The main performance of high pressure jump apparatus in our laboratory was measured. Shear strength parameters of several kinds of Chinese pyrophyllites were investigated by using Bridgman anvils in the high pressure jump apparatus and the pressure was calibrated by using Ba and Bi. Grounded on the above work, the following conclusion was obtained : the speed of pressure-jump is faster than 0.5GPa/ms in the compress course and the pressure range preponderated over 10GPa. The reaction pressure condition is superior to reported before and beneficial for measuring Grtlneisen parameter.The conclusion was made that the curve of temperature versus pressure of NaCl was in agreement with a conic in the adiabatic compression in our experiment. In accordance with Mean value Theorem of the differential calculus, it' s proved the ratio of change of temperature and pressure equaled to the tangent slope of the centre pressure, which showed dependence for measuring Grtlneisen parameter by a large pressure jump in principle.The lost heat in the experiment course was considered and a method of amending temperature in pressure-jump by descent curve of actual temperature was advanced. The calculational method afforded a new idea to achieve an adiabatic compression in actual compression and also solved the difficulty of achieving adiabatic compression in the...