近年来,由于科学的进步,美国氦需要量猛增。氦是核磁共振成像(MRI)、粒子加速器用超导磁体、航天飞机和武器等方面所不可缺少的一种气体。估计在80年代其需要量将猛增,但由于技术革新,也曾出现长期减少和不需要的兆头。用液氦冷却的超导磁体是40年代发现的,80年代开始,在医疗用核磁共振成像扫描仪方面达到了实用化。目前,美国使用 In recent years, due to scientific progress, the U.S. demand for helium has surged. Helium is an indispensable gas in MRI, particle accelerator superconducting magnets, spacecraft and weapons. It is estimated that its demand will soar in the 1980s, but there have also been long-term reductions and unnecessary signs due to technological innovations. Superconducting magnets cooled with liquid helium were discovered in the 1940s. Since the 1980’s, they have been put into practical use in medical MRI scanners. At present, the United States to use