DESIGN AND EXPERIMENTAL RESEARCH OF A LIQUID NITROGEN CRYOGENIC TARGET FOR CYLINDRICAL COMPRESSION

A liquid nitrogen cryogenic target for cylindrical compression has been designed and tested. The goal is to cool the sample from room temperature to the required low temperature, and maintain the temperature to liquefy the sample gas, providing the conditions for cylindrical isentropic compression. Design of structures was preliminarily completed according to the requirement of the compression mode and liquid sample preservation time, and optimized through the thermal analysis of the target. A test bed was built to measure the heat loss, cooling time, temperature control and keeping characteristics of the target under different conditions. The results show that the target temperature can be adjusted in a certain range according to the need. With a thermometer set inside the needle valve on top of the sample space and the repeatly partial filling method of the sample gas, it can be well observed that the liquefied sample is full of the sample space or not. The target succeeded in cooling the sample gas argon and the temperature keeping time can reach 93 minutes even when cold liquid nitrogen source and vacuum pump was disconnected.