Calculating Radiation Exchange Factors of Radiant Cryocooler by the Monte Carlo Method

Publisher Summary This chapter describes a computer program, intended for engineering calculation of radiation exchange factors of radiant cryocooler in real enclosure with diffuse emission and specular reflection surfaces. Spaceborne infrared imaging systems and infrared spectrometers are finding applications in the fields of earth resources, worldwide meteorological data gathering, and air and water pollution monitoring. These space sensors utilize a detector or cooler assembly which is usually designed to be sensitive in the mid-infrared region of the electromagnetic spectrum. Because of its passive operation and inherent long-term reliability, the radiant cooler offers numerous operational advantages over relatively heavy stored-cryogen coolers and power-consuming closed-cycle coolers. The method is a simple Monte Carlo application, and the flow chart of computer program is provided. The radiant exchange factors of a two-stage radiant cryocooler have been calculated. The results are discussed and compared with the data obtained by the ordinary specular image method. Comparison shows that the Monte Carlo method has equal or better effect in simple cases and strong potential in complex cases. So, it is very useful to the designers of radiant cryocoolers.