Ultra-sensitive Detectors for Astronomy

用于天文学的超灵敏探测器

• 批准号: ST/J001503/1
• 负责人: Ghassan Yassin
• 金额: $ 79.98万
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2012
• 资助国家: 英国
• 起止时间: 2012 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FJ001503%2F1
• 关键词: Ultra; sensitive; Detectors; Astronomy

The submillimetre-wave (3mm-300um) and far-infrared (300um-20um) regions of the electromagnetic spectrum are of considerable importance for astronomy because they contain a wealth of information about the cool, optically dark Universe. For example, the Cosmic Microwave Background radiation, which is a relic of the Big Bang, can be found at the longest wavelengths, whereas thermal radiation from distant, highly redshifted galaxies can be found at the shortest wavelengths. This part of the spectrum also contains thousands of spectral lines from numerous molecular and atomic species, which are important for studying the chemistry of regions where stars are being formed. It is exceptionally difficult, however, to make observations at submillimetre-wave and far-infrared and wavelengths because it is not possible to buy sufficiently sensitive cameras off of the shelf. Instead astronomers must develop their own imaging technology. These detectors must be highly sensitive, and must be cooled to temperatures of below 500mK. In addition, the instruments must be rugged, and capable of being flown in space. The proposed work aims to develop a new generation of extremely sensitive detectors and cameras by fabricating microcircuits out of materials called superconductors. Superconductors have the property that their electrical resistance falls to zero below some critical temperature, and magnetic flux is expelled. Indeed, the superconducting state is a special state of matter, and has many curious properties. By fabricating microcircuits out of the superconductors Nb, Ta, Al, and Mo, and by using modern Si micromachining techniques, it is possible to make detectors having exceptional properties. For example, our most recent infrared detectors are capable of detecting a light bulb being turned on and off for just 1 second at a distance of 10 million miles. The work will concentrate on understanding how to develop large-format cameras having thousands, and in some cases millions, of pixels. Four devices are of specific interest: (i) a device called a Transition Edge Sensor (TES), which operates by using the sharp transition of a superconductor to measure the minute change in temperature that occurs when infrared power is absorber by a tiny free-standing micro-machined silicon nitride island; (ii) a device called a Cold Electron Bolometer, which uses a solid-state refrigeration to achieve ultra-low-noise power detection; (iii) a device called a Kinetic Inductance Detector (KID), which essentially measures a small change that occurs in the amount by which a magnetic field penetrates into the surface of a superconductor when power is absorbed; and (iv) a device called a Superconductor Insulator Superconductor (SIS) mixer, which uses extremely thin layers of superconducting and insulating material to create diodes, which can be used to construct highly sensitive radio receivers. Each of these device types can be packed into arrays to form imaging systems of various kinds. Indeed, the wonderful scientific discoveries that were achieved in astronomy, in recent years, were only made possible by our ability to detect very weak signals coming from large radiotelescopes by using these tiny sub-micron devices. At the end of the program, we will have demonstrated a new generation of imaging technology based on superconducting devices, which will be available to construct the highly sensitive submillimetre-wave and far-infrared cameras that are needed for the next generation of ground-based and space-borne astronomy.

电磁波谱的亚毫米波（3 mm-300 um）和远红外（300 um-20 um）区域对天文学非常重要，因为它们包含了大量关于冷的、光学上黑暗的宇宙的信息。例如，宇宙微波背景辐射，这是大爆炸的遗迹，可以在最长的波长处找到，而来自遥远的，高度红移的星系的热辐射可以在最短的波长处找到。这部分光谱还包含来自许多分子和原子物种的数千条光谱线，这些光谱线对于研究恒星形成区域的化学性质非常重要。然而，在亚毫米波和远红外波段进行观测是非常困难的，因为不可能从货架上买到足够灵敏的照相机。相反，天文学家必须开发自己的成像技术。这些探测器必须高度敏感，并且必须冷却到500 mK以下的温度。此外，仪器必须坚固耐用，并能够在太空中飞行。这项拟议中的工作旨在通过用超导体材料制造微电路来开发新一代极其灵敏的探测器和相机。超导体具有这样的特性，即在某一临界温度以下，其电阻福尔斯降为零，并且磁通量被排出。事实上，超导态是物质的一种特殊状态，具有许多奇特的性质。通过用超导体Nb、Ta、Al和Mo制造微电路，并使用现代硅微机械加工技术，可以制造具有特殊性能的探测器。例如，我们最新的红外探测器能够在1000万英里的距离上探测到灯泡的开启和关闭，仅需1秒钟。这项工作将集中在了解如何开发具有数千，在某些情况下数百万像素的大画幅相机。有四种装置特别令人感兴趣：（i）称为过渡边缘传感器（TES）的装置，其工作原理是利用超导体的急剧过渡来测量当红外功率被微小的独立式微加工氮化硅岛吸收时发生的温度的微小变化;（ii）一种名为冷电子测辐射热计的设备，它使用固态制冷来实现超低噪声功率检测;（iii）称为动态电感检测器（KID）的装置，其基本上测量在吸收功率时磁场穿透进入超导体表面的量发生的微小变化;以及（iv）称为超导体绝缘体超导体（SIS）混合器的装置，其使用极薄的超导和绝缘材料层来产生二极管，其可用于构造高灵敏度无线电接收器。这些设备类型中的每一种都可以封装成阵列以形成各种类型的成像系统。事实上，近年来在天文学上取得的奇妙的科学发现，仅仅是因为我们有能力通过使用这些微小的亚微米设备来检测来自大型射电望远镜的非常微弱的信号。在项目结束时，我们将展示基于超导设备的新一代成像技术，该技术将用于构建下一代地基和星载天文学所需的高灵敏度亚毫米波和远红外相机。

项目成果

Investigating the Origin of Har- monics in a 230 GHz Local Oscillator

研究 230 GHz 本地振荡器中谐波的来源

• 发表时间: 2015
• 作者: Hector, A.

An SIS mixer based focal-plane array at 230 GHz

基于 SIS 混频器的 230 GHz 焦平面阵列

• 发表时间: 2015
• 作者: Leech, J.

Ultra-Wide Intermediate Bandwidth for High-Frequency SIS Mixers

适用于高频 SIS 混频器的超宽中间带宽

• DOI: 10.1109/tthz.2013.2296567
• 发表时间: 2014
• 期刊: IEEE Transactions on Terahertz Science and Technology
• 影响因子: 3.2
• 作者: Tan B

Experimental Investigation of a Low-Cost, High Performance Focal-Plane Horn Array

• DOI: 10.1109/tthz.2011.2177701
• 发表时间: 2012
• 期刊: IEEE Transactions on Terahertz Science and Technology
• 影响因子: 3.2
• 作者: J. Leech;B. Tan;G. Yassin;P. Kittara;S. Wangsuya

Development of NBN process for superconducting THz detectors and Mixers

超导太赫兹探测器和混合器的 NBN 工艺开发

• 发表时间: 2013
• 期刊: International Symposium on Space THz Technology
• 作者: Glowacka, D, Goldie, H. Muhammad, H., Withington, S., Yassin, G.