Search for Gravitational Radiation Using Ultralow Temperature Techniques

已研制出能在液氦温度（4.2K）下可靠工作的引力辐射共振质量探测器，灵敏度为h ~ 10 ~ 18。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。然而，建造超低温（40mK）探测器的技术，其灵敏度至少为h ~ 10-19，可能为10-20，足以探测可能发生在我们银河系或其邻近地区的天体物理事件的引力辐射。斯坦福大学的研究项目有以下几个关键要素：a)完成正在建设的超低温（40 mK）探测器，b)该探测器与其他引力波和中微子爆发探测器同时运行，c)现有的4 K探测器运行，直到超低温探测器可靠运行为止。d)继续推进超导调制电感换能器的最新研究；e)升级现有的4K探测器；F)研究先进探测器的发展，包括低频隔振和替代天线材料的研究。该小组率先建造了低温重力波接收器，并操作了世界上三个最灵敏的探测器之一。他们的接收器的进一步改进不仅将在寻找引力波方面发挥领导作用，还将在精密测量和隔振方面提供重要的技术副产品，这将对更广泛的社区有用。

Resonant-mass detectors of gravitational radiation have been developed that can be reliably operated at liquid helium temperature (4.2K) with sensitivities h ~ 10-18. At this sensitivity level we do not expect to detect gravitational wave signals from anything but the rarest astrophysical events. However, the technology to build an ultralow temperature (40mK) detector with sensitivity of at least h ~ 10-19 and likely 10-20, sufficient to detect gravitational radiation from plausible astrophysical events that could occur in our galaxy or its immediate vicinity, is in hand. The Stanford research program has the following key elements: a) completion of an ultralow temperature (40 mK) detector now under construction, b) operation of this detector in coincidence with other gravitational wave and neutrino burst detectors, c) operation of the existing 4 K detector until reliable operation of ultralow temperature detector is achieved, d) continuing research to advance the state-of-the-art in superconductive modulated-inductance transducers, e) upgrade of the existing 4K detector, f) research on advanced detector development including low-frequency vibration isolation and investigation of alternative antenna material. This group has pioneered the construction of cryogenic gravity wave receivers, and operates one of the three most sensitive detectors in the world. Further improvement of their receiver will not only provide leadership in the search for gravitational waves, it will provide important technological spin-off in precision measurements and vibration isolation which will be of use to a wider community.