Research On X-ray Low Temperature Radiometer Control And Data Acquisition System

Cryogenic radiometer is a standard instrument for measuring optical power.It is widely used in the fields of radiation measurement,optical radiation metrology,spectroscopy,and astrophysics and so on.At present,in the field of optical radiation metrology,cryogenic radiometer has been regarded as detector standard by international research institutes for standardization,which has the most accurate measurement of radiant power.Cryogenic radiometer measure radiant power based on the equivalence of electric and radiation heating.The core idea of cryogenic radiometer is thermal equilibrium,which is equivalent to temperature.Temperature measurement and control are the key factors affecting the accuracy of optical power measurement.So it is very important to optimize the temperature control system of cryogenic radiometer.The main work of this paper is to design a temperature control system of cryogenic radiometer,which is suitable for the Beijing synchrotron radiation soft-X-ray.According to the design index of the temperature control system,the hardware and software of the temperature control system are designed respectively.The hardware design adopts some instruments and devices to achieve low noise temperature measurement and control of the heat sink and absorber.The software design use the Labview programming system and PID(Proportion-Integral-Derivative)control algorithm to achieve the automatic and precise control of temperature.In addition,the control system is debugged,the program is optimized according to the results of the test,and then the experiments are carried out to determine the optimal parameters.And the factors that affect the response time and stability of temperature control according to the measurement data are analyzed.The experimental results show that heat sink’s temperature change standard is less than 10μK,and absorber’s temperature change standard is from 80μK to 120μK.