Fast, high precision, low cost position diagnostic for free electron lasers

电子束仪器是操作员将电子束传输到自由电子激光器(FEL)的眼睛和耳朵。特别是，位置诊断有助于优化并随后重现整个FEL中电子的“黄金”路径，以确保在FEL的输出中获得最佳质量和最明亮的X射线光脉冲。重要的是要为利用X射线的实验维持最好的可能条件，这可以包括从考古学到生物科学，从安全到纳米材料的各种调查。对于设计自由电子激光器并驱动它们的直线加速器(直线加速器)的科学家和工程师来说，以更低的成本提供更好的性能是一个永无止境的追求。不可避免的是，人们需要新的想法。我们的项目是这一探索的一部分：我们有一个想法，如何在不增加成本的情况下，用更新、更高分辨率、更快的类型来取代旧的波束位置诊断。这一新想法是波导束位置监测器(WGBPM)。WGBPM模型已经在我们的实验室中展示了它们的基本功能，但要将这项工作转化为可以安装在现实生活中的电子加速器中的演示原型，仍然需要付出巨大的努力。因此，我们将重点开发用于真实生活中的原理验证实验的硬件和方法。这将涉及多个3D电磁模拟，以优化设备并预测其输出，与机械工程师合作，确保设备可以轻松制造，并满足加速器机器的所有复杂要求。WGBPM产生的信号是非常短的电脉冲，需要将其转化为有用的信息。我们将设计模拟电子学，帮助准备这些脉冲，以便跨越模拟和数字世界之间的边界，并研究从数字化信号中提取位置信息的算法。然后，我们希望进行关键测试，将原型安装在现实生活中的加速器中，使其暴露在电子束中。我们希望看到该设备确实能够以它应该的方式感知光束的位置，并确认我们对它提供的输出的期望以及它能够感知光束位置的精度。在这个项目结束时，我们希望能够开始“知识交流”：与一家公司合作，努力使波导束位置监测器以完整的商业产品的形式提供给世界各地的科学家。

Beam instrumentation are the eyes and ears of an operator delivering an electron beam to a free electron laser (FEL). In particular, position diagnostics help optimising and later reproducing the "golden" path for electrons throughout the FEL that ensures the best quality and brightest burst of X-ray light at the FEL's output. It is important to sustain the best possible conditions for experiments making use of the X-rays, which can include a wide variety of investigations, in subjects ranging from archeology to bio-science, from security to nanofabrication.It is a never ending quest for scientists and engineers designing FELs and driving them linear accelerators (linacs) delivering the electrons for lasing, to provide better performance at a lower cost. Inevitably, new ideas are in demand. Our project is part of this quest: we have an idea on how to replace older beam position diagnostics with a newer, higher resolution, faster type without inflating the cost. This new idea is waveguide beam position monitors (WGBPM).WGBPM models have demonstrated their basic functionality in our laboratory, but significant effort is still needed to convert this work into a demonstrator prototype that can be installed in a real life electron accelerator. Therefore, we will focus on developing the hardware and methods for a real life proof-of-principle experiment. This will involve multiple 3D electromagnetic simulations to optimise the device and predict its output, work with mechanical engineers to ensure the device can be easily manufactured and all the complex demands of an accelerator machine are met.The signals produced by WGBPMs are very short electric pulses, which will need to be turned into useful information. We will design analogue electronics which will help preparing these pulses for crossing the boundary between the analogue and digital worlds and also work on algorithms that extract the position information from the digitised signals.We are then hoping to proceed to a critical test, installing the prototype in a real life accelerator exposing it to a beam of electrons. We want to see that the device can indeed sense the beam's position the way it is supposed to, and confirm our expectations on the output it gives and the precision it can sense the beam position with.By the end of this project we would like to be able to start "knowledge exchange": team up with a company and work towards making waveguide beam position monitors available to scientists worldwide in a form of a complete, commercially available product.