Search for Gravitational Radiation Using Ultralow Tempera- ture Techniques (Physics)

研制了一种能在液氦温度(4.2K)下可靠工作的引力辐射共振质量探测器，其灵敏度为h~10-18。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。然而，建造超低温(40mK)探测器的技术正在进行中，该探测器的灵敏度至少为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可能发生的天体物理事件的引力辐射。斯坦福大学的研究计划有以下关键要素：a)正在建造的超低温(40MK)探测器的完成，b)该探测器与其他引力波和中微子爆发探测器的运行，C)运行现有的4K探测器直到实现超低温探测器的可靠运行，d)继续研究以推进超导调制电感换能器的最新技术，e)升级现有的4K探测器，F)研究先进探测器的开发，包括低频隔振和研究替代天线材料。该小组率先建造了低温重力波接收器，并操作着世界上三个最灵敏的探测器之一。他们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，还将在精密测量和振动隔离方面提供重要的技术衍生产品，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 4 K 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.