Structural characterization of thin carbon films on high-current silicon field emitters

Adaptix是一家位于牛津大学科技园的中小企业，开发低成本、低剂量、便携式3D X射线源。其核心技术是一个“分布式阵列”，它将光源数字化，用大量可寻址的低功率发射器取代单个高功率管，并与现代平板探测器结合使用。因此，在急诊室（A&E，ICU）和初级保健中，2D诊断被3D（数字断层合成）所取代，从而改善了整体的初始诊断。Adaptix目前正在销售其用于兽医的设备，并正在扩展其用于无损评估应用的技术，以及其最大的市场，ortho x射线成像，胸部和牙科。对于某些应用，它需要增加其面板X射线源的亮度，例如在胸部成像中，由于人体胸部的厚度，覆盖不同类型的组织，骨骼，肌肉等。通过新的蚀刻和涂层技术开发发射器阵列是Adaptix目前的优先事项。对于理论背景，我们正在与来自法国塔尔图和里昂大学的场致发射体建模和表征方面的领先专家合作。在硅发射体上的惰性涂层的初步实验在改善电流发射（3倍）方面取得了非常有希望的结果。与西苏格兰大学和达雷斯伯里的STFC合作，我们正在研究制造这种惰性涂层的各种方法。初步结果显示，发射器的性能变化很大。我们将此归因于膜的组成和结构，已知在不同的涂覆技术中变化很大，但我们没有办法解决这个问题。增加的电流发射（2- 3倍）我们在一些涂层样品中观察到的更长的使用寿命将是我们技术的真实的改变，并为我们打开新的市场。Adaptix没有敏锐的科学知识，分析或所需测量的设施。通过与NPL的合作，我们希望能够了解我们涂层的成分。我们的目标是获得可重复的、稳定的结果。另一个目标是在我们的生产设施中开发一种质量控制方法。

Adaptix is a SME based at the Oxford University Science Park that develops low-cost, low-dose, portable 3D x-ray sources. The core technology is a 'Distributed Array' that digitises the source, replacing a single high-power tube with a multitude of addressable low-power emitters in conjunction with modern Flat Panel Detectors). Thus 2D diagnostics is replaced with 3D (digital tomosynthesis) in the acute care setting (A&E, ICU), and into Primary Care, improving initial diagnosis overall.Adaptix is currently selling its units for veterinarians, and is expanding its technology for the Non-Destructive Evaluation applications and for its biggest market, ortho x-ray imaging, chest and dental. For some applications it needs to increase the brightness of its panel x-ray source, e.g in chest imaging, because of the thickness of the human chest, with overlaying different types of tissue, bone, muscle etc.The development of the emitters' array by novel etching and coating technologies is Adaptix' current priority. For the theoretical background we are collaborating with leading experts in the modelling and characterization of field emitters from the Universities of Tartu and Lyon in France.Preliminary experiments on an inert coating on the silicon emitters held very promising results in terms of the improved current emission (3x) and its stability.In collaboration with the University of West Scotland and STFC in Daresbury we are investigating various methods for the fabrication of this inert coating. Initial results exhibit a huge variation in the performance of the emitters. We ascribe this to the film composition and structure, known to vary a lot among different coating techniques, but we have not the means to characterise that.The increased current emission (2-3X) and the improved lifespan that we observe in some of the coated samples would be a real game changer for our technology and open new markets for us.Analytical tools to characterise the exact structure and composition of the coatings are not easily available and Adaptix does not have the acute scientific know-how, analysis or facilities for the required measurements.In collaboration with NPL we hope to be able to understand the composition of our coatings. With this we aim for reproducible, stable results. An additional goal is also to develop a method for quality control in our production facility.