Search for Gravitational Radiation Using Ultralow Temperature Techniques

我们研制的引力波共振质量探测器在液氦温度(4.2K)下工作可靠，灵敏度为h~6×10~(-19)，其中h是波的无量纲应变幅度。在这种灵敏度水平下，除了最罕见的天体物理事件外，我们不希望探测到任何引力波信号。在过去的几年里，斯坦福大学的团队一直在设计和建造一种超低温(50mK)探测器。预计它的初始灵敏度至少为h=10-19，最终低于10-20，足以探测到可能发生在我们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。这一努力的成功可能会直接证实爱因斯坦广义相对论的一个重要预测，并为我们的宇宙打开一扇全新的窗口，将产生光学、射电、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：即将完成的超低温(50mk)探测器的可靠运行；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，伽马射线爆发)和中微子爆发探测器相关联。继续研究以推进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.