[en] The thermohydraulic behavior of the liquid-metal target of the spallation neutron source at Paul Scherrer Institute has been investigated. The configuration is a natural-circulation loop in a concentric double-tube-type container. The model is based on one-dimensional loop analysis, and the thermohydraulic behavior of the target liquid, as well as the total performance of the target, are studied analytically and numerically. These results are verified by two experiments using liquid metal. The results show that the natural-circulation loop concept is valid for the design phase of the target construction, and the current specified design criteria will be fulfilled with the proposed parameter values