An infrared (IR) detector is simply a transducer of radiant energy, converting radiant energy into a measurable form. Since radiation does not rely on visible light, it offers the possibility of seeing in the dark or through obscured conditions, by detecting the IR energy emitted by objects. One of the prime applications of IR detector systems for military use is in target acquisition and tracking of projectile systems. The IR detectors also have great potential in commercial market. Typically, IR detectors perform best when cooled to cryogenic temperatures in the range of nearly 120 K. However, the necessity to operate in such cryogenic regimes makes the application of IR detectors extremely complex. Further, prior to proceeding on to a full blown transient thermal analysis it is worthwhile to perform a steady-state numerical analysis for ascertaining the effect of variation in viz., material, gas conduction coefficient, h, emissivity, ε, on the temperature profile along the cryo chamber length. This would enable understanding the interaction between the cryo chamber and its environment. Hence, the present work focuses on the development of steady-state numerical models for thermal analysis of IR cryo chamber using MATLAB. The numerical results show that gas conduction coefficient has marked influence on the temperature profile of the cryo chamber whereas the emissivity has a weak effect. The experimental validation of numerical results has also been presented.
One of the primary requirements for operation of Infrared (IR) detector systems for defence applications is the availability of a reliable miniature cryocooler. Due to a simple configuration, compact and light structure and rapid cool down characteristics, miniature Joule Thomson (JT) cryocoolers are considered ideal for IR detector systems. The need for high purity gas supply is a main concern in order to ensure long and reliable operation of Joule Thomson miniature cryocoolers. Minute solid particles are the common and problematic impurity which on being lodged in the cooler orifice hampers the cryo-cooling process of the cooler by choking which affects the operation of IR detector packaged in an Infrared detector cryochamber or dewar.
The paper focuses on realization of sintered porous neck filter, the developmental aspects of the same and its characterization. In the present work a sintered porous neck filter with 5μm pore size and a filter porosity of nearly 35% was developed. The filter developed was assembled at the warm end of the cooler and the cooler assembly was integrated in the IR cryochamber for in system evaluation and confirmation of the desired quality of the developed porous filter.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.