4 K pulse tube cryocooler (IMAGE) American Institute of Physics Caption 4 K pulse tube cryocooler developed by researchers at the Technical Institute of Physics and Chemistry, Chinese Academy of Sciences Credit Liubiao Chen/University of Chinese Academy of Sciences Usage Restrictions Journalists may use this image only with appropriate credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.