ET-R&D - Networking and R&D for the Einstein Telescope

引力波是广义相对论的最后一个预言，目前仍在等待直接的实验检测。在过去的二十年里，在世界各地建造和优化大型干涉仪的努力导致了具有非凡灵敏度的仪器的出现。虽然英国/德国的引力波探测器GEO 600目前正在采集数据，但美国的LIGO探测器和法国/意大利的处女座探测器正在升级，以进一步提高它们的灵敏度。一旦这些升级达到了它们的设计灵敏度，理论上的估计就会在几个月到一年内探测到引力波。虽然可能会有频繁的探测，但高信噪比事件的探测将非常罕见，从而实现精确的引力波天文学。ET-R&D项目旨在完成基本的研发任务，为爱因斯坦望远镜的技术设计做准备，爱因斯坦望远镜是第三代地下引力波探测器。人们普遍预计，这个探测器将允许进行常规的引力波天文学。虽然基本设计主要依赖于先进探测器的良好开发和测试技术，但仍有几个方面需要长时间的研发。我们建议通过5个工作组(WG)在这个ET-R&D项目中针对这些最重要的主题。WG1将探索天体物理源模型和GR本身如何能够用ET进行测试，以及从数据中可以提取多少关于宇宙动力学的信息。WG2将收集各种候选地点的长期地震数据，并开发测量地震运动的方法，这些方法直接与测试质量运动耦合，目标是开发减法技术。WG3将研究低温光学的特性，这些特性对于降低探测器的热噪声和提供良好的低频性能至关重要。WG4将研究三种不同ET探测器数据中各种干涉仪自由度和噪声相关性的控制。WG5将重点放在整体项目管理上。苏格兰西部大学将在WG3中发挥关键作用，协助表征大块硅材料的光学性质。此外，UWS将利用UWS薄膜中心提供的独特沉积设备，与英国和欧洲的其他实验室合作，制造超纯非晶硅薄膜涂层，以进行表征，并可能用于爱因斯坦望远镜光学元件的多层镜膜。

Gravitational waves are the last prediction of general relativity still awaiting direct experimental detection. The efforts in constructing and optimising large interferometers in different locations all over the world in the last two decades have resulted in instruments of extraordinary sensitivity. While the British/German gravitational wave detector GEO 600 is currently taking data, the American LIGO detectors and the Franco/Italian Virgo detector are being upgraded to further increase their sensitivity. Once these upgrades have reached their design sensitivity the theoretical estimates predict the detection of gravitational waves within a few months to a year. Although frequent detections will be possible, the detection of high signal to-noise ratio events, allowing precision gravitational wave astronomy, will be very rare.The ET-R&D project is aimed at essential R&D tasks in preparation for a technical design of the Einstein Telescope, a 3rd generation, underground gravitational wave detector. It is widely expected that this detector will allow routine gravitational wave astronomy to take place. While the basic design mostly relies on techniques well developed and tested for the advanced detectors, several aspects still require R&D with long lead times. We propose to target the most important of these topics in this ET-R&D project via 5 working groups (WGs).WG1 will explore how well astrophysical source models and GR itself can be tested with ET, and how much information on the dynamics of the universe can be extracted from the data. WG2 will collect long term seismic data for various candidate sites and develop methods for measuring the seismic motion which directly couples to the test mass motion, with the goal of developing subtraction techniques. WG3 will investigate properties of cryogenic optics essential for lowering detector thermal noise and providing good low frequency performance. The control of various interferometer degrees of freedom and noise correlations in the data of the three different ET detectors will be studied in WG4. WG5 will focus on overall project management. The University of the West of Scotland will play a key role in WG3, assisting in the characterisation of the optical properties of bulk silicon materials. In addition, UWS will fabricate ultra-pure amorphous silicon thin film coatings, using the unique deposition facilities available in the Thin Film Centre at UWS, for characterising in collaboration with other labs across the UK and Europe for possible use in multilayer mirror coatings for the optics of the Einstein Telescope.