A Facility for Ambient Pressure Photoelectron Spectroscopy (APPES) (R)

50多年来，x射线光电子能谱（XPS）已被证明是研究固体填充电子态的宝贵技术，也有助于确定固体表面与分子物种之间相互作用的性质。不幸的是，该技术有一个主要缺点，即典型的XPS测量是在超高真空（UHV）条件下（10-10毫巴）进行的，因为需要在激发的光电子到达能量分析仪之前最大限度地减少发生不利碰撞的机会。由于这种限制，研究技术上重要的材料表面的压力比系统本身的工作条件（1-50 bar）低许多个数量级。弥合这种所谓的“压力差距”仍然是一项重大的技术挑战。电子能量分析仪和样品架设计的最新发展首次允许在高达25毫巴的环境压力下进行光电子能谱测量。在现场和操作中研究“真实”表面的机会是光电子能谱领域的一个重大变化，并在表面科学领域开启了新的重要篇章。环境压力光电子能谱（APPES）系统是一种最先进的实验室仪器，能够在高达25毫巴的环境压力下使用多种不同的气体（O2、N2、H2、乙烯、乙炔）进行高能量分辨率、低信噪比的光电发射测量。该仪器配备了一个单色x射线源和一个高透射、差动泵浦电子能量分析仪。该系统配备了一个原位样品池，可以在环境气氛中提供80 - 1100 K的温度范围，允许在操作中进行测量。这种特别设计的模块化原位细胞，可以从分析室完全伸缩，也可以轻松地进行标准的特高压XPS比较测量。设在伦敦帝国学院材料系的APPES仪器将是高度多学科的，包括五个广泛的研究主题(i)能源；(2)催化;电子材料；(四)生物材料;环境和遗产科学。该仪器由帝国理工学院主办，在区域、国家（包括钻石光源）和国际层面上进行高度合作研究，并通过协调纽卡斯尔大学的国家XPS设施（NEXUS）提供访问安排。这种提供广泛访问的新方法将使APPES技术得到充分利用，并产生世界领先的尖端科学成果。

For over 50 years, x-ray photoelectron spectroscopy (XPS) has demonstrated itself as an invaluable technique in the study of filled electronic states of solids, as well helping to determine the nature of interactions between solid surfaces and molecular species. Unfortunately there is one main drawback in the technique, that being that typical XPS measurements are performed in ultra high vacuum (UHV) conditions (10-10 mbar), due to the need of minimising the chances of unfavourable collisions occurring before the excited photoelectrons reach the energy analyser. Due to this restraint, studying the surfaces of technologically important materials occurs at a pressure many orders of magnitude lower than the operational conditions of the systems themselves (1-50 bar). Bridging this so-called "Pressure Gap" has remained a significant technological challenge. Very recent developments in electron energy analyser and sample holder design have for the first time allowed photoelectron spectroscopic measurements to be performed in ambient pressures of up to 25 mbar. The opportunity to study "real" surfaces in-situ and in-operando is a step change in the field of photoelectron spectroscopy, and opens a new and vital chapter in the area of surface science.The ambient pressure photoelectron spectroscopy (APPES) system is a state-of-the-art laboratory-based instrument with capabilities of performing high-energy resolution, low signal-to-noise photoemission measurements in up to 25 mbar ambient pressure with a number of different gases (O2, N2, H2, ethylene, acetylene). The instrument is equipped with a monochromated x-ray source and a high transmission, differentially pumped electron energy analyser. The system is fitted with an in-situ sample cell, which can provide a temperature range of 80 - 1100 K in the ambient atmospheres, permitting in-operando measurements. This specially designed modular in-situ cell, which is fully retractable from the analysis chamber, also allows standard UHV XPS comparative measurements to be performed with ease.The APPES instrument based at the Department of Materials, Imperial College London will be highly multidisciplinary, covering five broad research themes (i) Energy; (ii) Catalysis; (iii) Electronic Materials; (iv) Biomaterials; (v) Environmental and Heritage Science. The instrument, while hosted at Imperial is engaged in highly collaborative research at a regional, national (including the Diamond Light Source) and international level, with access arrangements also provided through coordination the National XPS Facility (NEXUS) at the University of Newcastle. This new approach to providing wide- reaching access will allow the APPES technique to be fully exploited and generate world-leading cutting edge scientific output.