What is the record in the history books about Emperor Wu of the Han Dynasty seeking immortality and medicine?

Emperor Wu of the Han Dynasty sought immortality and medicine, which was of great scale and far-reaching influence. First of all, "there are tens of thousands of people who say that there are strange people, but there are no witnesses." Emperor Wu "built a boat so that thousands of people who talked about God in the sea could ask for Penglai God." Among so many alchemists, Shao Weng, Luan Da, Kuan Shu and Gong are all recorded in Historical Records and Hanshu. But the most important one is Li. Sima Qian's Historical Records and Closed Sutra vividly recorded the activities of Li, Luan Da and others in the period of Emperor Wu of the Han Dynasty.