ET R&D

引力波是广义相对论的最后一个预言，仍在等待直接的实验检测。过去二十年来，在世界各地不同地点建造和优化大型干涉仪的努力已经产生了具有非凡灵敏度的仪器。虽然英国/德国的引力波探测器GEO 600目前正在收集数据，但美国的LIGO探测器和法国/意大利的Virgo探测器正在升级，以进一步提高其灵敏度。一旦这些升级达到了它们的设计灵敏度，理论估计预测在几个月到一年内探测到引力波。虽然频繁的探测是可能的，但高信噪比事件的探测，使精确的引力波天文学，将是非常罕见的。ET-R&D项目的目的是必要的研发任务，准备爱因斯坦望远镜的技术设计，第三代，地下引力波探测器。人们普遍预计，这个探测器将允许常规的引力波天文学发生。虽然基本设计主要依赖于为先进探测器开发和测试的技术，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）来瞄准ET-R&D项目中最重要的主题。WG 1将探索如何使用ET测试天体物理源模型和GR本身，以及可以从数据中提取多少关于宇宙动力学的信息。第二工作组将收集各种候选场地的长期地震数据，并开发直接与试验块体运动耦合的地震运动测量方法，目的是开发减法技术。第三工作组将研究低温光学的特性，这些特性对于降低探测器热噪声和提供良好的低频性能至关重要。第四工作组将研究三种不同ET探测器数据中各种干涉仪自由度和噪声相关性的控制。第五工作组将侧重于总体项目管理。格拉斯哥大学将在其中三个工作组中发挥关键作用。在WG 1中，我们将通过应用我们现有的引力波数据分析专业知识，开发ET检测到的瞬态信号的参数估计方法。在WG 3中，我们将开发用于测量涂层硅样品双折射的仪器，并应用我们在有限元建模方面的专业知识，以协助解释与汉诺威和耶拿合作进行的低温双折射测量。在WG 4中，我们将对ET的传感和控制问题进行研究和模拟，并对量子噪声和光学配置进行详细建模。与我们的英国和欧洲合作伙伴的合作以及现有设施和专业知识的结合将是该提案成功的关键。

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. Glasgow University will play a key role in three of the working groups. In WG1, we will develop methods of parameter estimation for transient signals detected by ET, through application of our existing expertise in gravitational wave data analysis. In WG3 we will develop apparatus for measuring the birefringence of coated silicon samples and apply our expertise in finite element modelling to assist in the interpretation of cryogenic birefringence measurements carried out in collaboration with Hannover and Jena. In WG4 we will carry out studies and simulations of sensing and control issues for ET and carry out detailed modelling of the quantum noise and optical configuration. Collaboration with our UK and European partners and combination of the facilities and expertise available will be essential for the success of this proposal.