| Temperature is one of the most important parameters to describe the thermodynamical complete equations of state(EOS),the precise temperature measurement has become the key to test the physical models and construct the various EOS.The pyrometer based on the Planck radiation has been used very successfully and frequently in the shock wave experiments due to its portability and wide applicability.But,this technique has faced an obstacle when it was used to measure the shock temperature below 2500 K.In fact,when the shock temperature is below 2500 K,the peak wavelength of the thermal radiation is in the near-infrared wavelength or in the infrared wavelength.The wavelength range of the near-infrared or infrared pyrometer is 1?3 ?m(even much broader),which is much broader than the visible pyrometer(?0.5 ?m)and the uncertainty of the temperature measurement due to the unknown emissivity increases with increasing the wavelength.So,the Planck fitting of the radiance based on the gray body model will not always acquire a satisfactory result.And the dynamic emissivity of many samples has presented strong dependence on pressures,temperatures and the sample surface status.So,the dynamic emissivity and the radiance must be measured simultaneously in one single shot when the shock temperature is below 2500 K.According to the simultaneous measurement of the dynamic emissivity and the radiance,this dissertation has been focused on the proposed novel method and its key techniques,e.g.,the principle of simultaneous measurement,the experimental system design,the data analysis and its uncertainty evaluation,the dynamic experimental design and the results analysis.The main contents and contribution of this dissertation are as follows:(1)A novel method has been proposed to simultaneously measure the dynamic emissivity and the radiance.In this method,the sequence rectangle laser pulses have been used to illuminate the sample/window interface via an integrating sphere,and the laser pulses reflected from the sample/window interface was superimposed on the thermal radiation of the sample/window interface at the expected steady state by the time sequence precision control.So,the dynamic emissivity and the radiance can be acquired simultaneously.By this method,the temperature of the sample/window interface can be acquired accurately in one single shot with the single wavelength.And this method has obviated absolutely the Gray body model assumption of the traditional method of shock temperature measurement.The problem of temperature precision measurement due to the uncertainty of the dynamic emissivity has been resolved.(2)The experimental techniques of this method have been systemically studied.With the electron-optic modulation and acousto-optic modulation methods,the sequence rectangle laser pulses with high stability have been acquired.By the refined analysis of the dynamic scheduling relations,the arriving time synchronization at the sample/window interface between the shock wave and the rectangle laser pulses has been resolved.At last,a three-wavelength system has been designed,and the guide line of every part of this system has been introduced,the data processing and the uncertainty evaluation method have been analyzed.By resolving these problems,the temperature precision measurement method for 1500?2500 K has been established.(3)Two experimental runs have been performed to measure the shock temperatures of A1 and Sn with our proposed method.The experiment results are consistent with the latest theoretical calculations.When the gray body assumption was used,the acquired fitting temperatures were higher 300?500 K than the theoretical calculations and this discrepancy may come from the gray body assumption in the visible-nearfrared wavelength range.The results of Al have clarified the divergence between the theoretical calculations and the pyrometer measurement results.And the results of Sn have verified the latest theoretical calculations of multi-solid phase theoretical EOS. |
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