Speaker
Erik Iverson
(Oak Ridge National Laboratory)
Description
We present the design and experiences with a real-time monitor, based on Raman spectroscopy, for tracking the orthohydrogen fraction in an operating liquid hydrogen moderator loop on a neutron source. This diagnostic probes the hydrogen through transparent windows, without crossing the hydrogen boundary. It can track orthohydrogen levels as low as 0.15%, enabling confirmation of full thermodynamic equilibrium at less than 20 K. Using this probe, we have verified that the catalyst converter system, installed in the Cold Moderator System at the Spallation Neutron Source, effectively counters radiation-induced backconversion, and supports the operation of the SNS hydrogen moderators at that thermodynamic equilibrium.
Authors
Erik Iverson
(Oak Ridge National Laboratory)
Brian DeGraff
(Oak Ridge National Laboratory)
John Denison
(Oak Ridge National Laboratory)
Franz Gallmeier
(Oak Ridge National Laboratory)