Search for Gravitational Radiation Using Ultralow Temperature Techniques

已研制出在液氦温度（4.2K）下可靠工作的引力辐射共振质量探测器，灵敏度为h ~ 6x10-19，其中h为引力波的无量纲应变幅值。在这个灵敏度水平上，除了最罕见的天体物理事件，我们不期望探测到任何东西的引力波信号。在过去的几年里，斯坦福大学的研究小组一直在设计和建造一个超低温（50mK）探测器。预计它的初始灵敏度至少为h=10-19，最终小于10-20，足以探测可能发生在银河系或其邻近地区的看似合理但罕见的天体物理事件的引力辐射。这一努力的成功将直接证实爱因斯坦广义相对论的一个重要预言，并为我们的宇宙打开一扇全新的窗口，将获得光学、无线电、红外、x射线或伽马射线天文学无法获得的信息。未来三年研究计划的关键要素是：超低温（50mk）探测器的可靠运行，目前已接近完成；该探测器与其他引力波探测器同时运行>，并将输出与其他电磁（例如伽马射线暴）和中微子暴探测器相关联，>继续研究超导调制电感换能器和squid的最新技术。

Resonant-mass detectors of gravitational radiation have been developed that are reliably operating at liquid helium temperature (4.2K) with sensitivities h ~ 6x10-19, where h is the dimensionless strain amplitude of the waves. At this sensitivity level we do not expect to detect gravitational wave signals from anything but the rarest astrophysical events. For the past several years the Stanford group has been designing and constructing an ultralow temperature (50mK) detector. It is expected to have an initial sensitivity of at least h=10-19 and eventually less than 10-20, sufficient to detect gravitational radiation from plausible but rare astrophysical events that could occur in our galaxy or its immediate vicinity. Success in this endeavour could bring direct confirmation of an important prediction of Einstein's General Theory of Relativity and also open an entirely new window on our universe that will yield information not available from optical, radio, infrared, x-ray, or gamma-ray astronomy. The key elements of the research program during the next three years are > reliable operation of the ultralow temperature (50mk) detector now nearing completion, > operation of this detector in coincidence with other gravitational wave detectors and correlate the output with other electromagnetic (e.g., gamma-ray burst) and neutrino burst detectors, > continuing research to advance the state-of-the-art in superconductive modulated-inductance transducers and SQUIDs.