Patent ID: 8474272

Claim:
A multistage pulse tube cooler comprising: a compressor; a first stage comprising: a first stage regenerator comprising a first end in fluid communication with the compressor and a second end; and a first stage pulse tube comprising a cold end in fluid communication with the second end of the first stage regenerator and a hot end; a first stage reservoir in fluid communication with the hot end of the first stage pulse tube; a first stage control valve positioned between the first stage reservoir and the first stage pulse tube; a first stage phase control device positioned between the first stage reservoir and the first stage pulse tube; and a second stage comprising: a second stage regenerator having a first end in fluid communication with the second end of the first stage regenerator and a second end; and a second stage pulse tube comprising a cold end in fluid communication with the second end of the second stage regenerator and a hot end; a second stage reservoir in fluid communication with the hot end of the second stage pulse tube; a second stage control valve positioned between the second stage reservoir and the second stage pulse tube; and a second stage phase control device positioned between the second stage reservoir and the second stage pulse tube, wherein the cold end of the first stage pulse tube and the hot end of the second stage pulse tube are in fluid communication via an inter-stage flow control device, wherein the inter-stage control valve is positioned between the cold end of the first stage pulse tube and second stage control valve.