Investigation on a 130 Hz miniature coaxial pulse tube cryocooler.

A 130 Hz miniature coaxial pulse tube cryocooler is designed and manufactured for infrared and electronic applications which limit size and mass strictly and demand fast cool down. The design goal is to provide the cooling power of over 1 W at 80 K with less than 1 kg. The operating frequency is increased up to 130 Hz and the average pressure enhanced to about 3.6 MPa so as to make up for the losses caused by the significant decrease of the cooler volume and mass. The micro compressor is scaled down from mid-size moving-coil dual-opposed linear compressors developed in the same laboratory. Scale factors based on scaling principles are modified to adapt to the micro design. The scaling process results in an overall compressor mass of nearly 650 g while resonating at 130 Hz. The no-load characteristic of the linear motor is analyzed initially. Geometrical dimensions of the coaxial cold finger and operating parameters are optimized by numerical simulations. A simulated cooling capacity of 1.71W at 80 K with an input PV power of 40 W can be achieved. The total cooler mass is estimated about 920 g.