After nearly 6 years of design and fabrication work, the initial cool down of the PULSTAR Ultra Cold Neutron Source cryostat took place on January 6, 2012. This first round of cryogenic testing used liquid nitrogen to cool each of the cooling loops to 70K. All cryogenic, instrumentation, and vacuum system components were checked, and the thermal properties of the system were analyzed.All systems performed as expected, so the UCN team is currently planning for the next round of cooling tests using liquid helium scheduled for Fall 2013.
