net-zero - Tracking tritium to enable efficient fusion fuel cycles

英国政府已立法规定到2050年实现温室气体净零排放，并承诺通过建立STEP计划，在2040年之前建造一座原型紧凑型发电厂--对英国来说，这是一个非常令人兴奋的项目，并承诺“加倍努力，成为聚变能源技术商业化的第一个国家”。Building Step是一项非常重大的技术挑战，但英国在这方面拥有出色的血统和专业知识。此外，英国还参加了欧洲原子能研究和培训方案，因此仍然是规模更大的热核聚变项目(法国南部的国际聚变项目)和欧洲核聚变示范发电厂方案的全面参与者，目标是在热核实验堆开始其第一次聚变实验20年后的聚变电。虽然STEP和DEMO是由净零目标驱动的综合发电厂设计方案，但仍必须同时克服相当大的技术不确定性。这项概念验证提案由布里斯托尔大学(UOB)牵头，与UKAEA(领导英国聚变研究的政府研究组织)合作，将寻求解决聚变发电站的一项关键技术“拦路虎”：监测氚，这是聚变能源的放射性燃料成分。氚是氢的一种微弱的贝塔重同位素，贝塔辐射能量平均为5.7keV，这意味着探测器材料中氚衍生的贝塔粒子的阻止范围极其有限，大约在微米量级。需要监测聚变发电站许多不同部分的氚丰度，从堆芯到增殖包层(产生氚的地方)，再到后端分离和储存工厂，在那里使用低温(非常低)的温度来帮助进行这一过程。因此，任何探测器都需要能够承受极端的温度，并且仍然能够以可靠的方式工作。该项目将生产第一个紧凑的固态氚探测器，其独特的装置结构由钻石制成，使其能够在极端寒冷和高温下工作，从非常低的氚含量到非常高的氚含量。开发这种设备将需要开发材料，采用独特的逐层生长方法，并开发可以快速计算撞击探测器的β粒子的电子设备。因此，这个令人兴奋的项目将涉及建模、材料生长、电子设计、设备测试和校准。所有这些都是为了创造一种新型的探测器，这将是帮助聚变发电厂运行的关键。

The UK government has legislated to deliver 'net-zero' greenhouse gas emissions by 2050 and committed to "doubling down on our ambition to be the first country to commercialise fusion energy technology" by establishing the STEP programme to build a prototype compact power plant by 2040 - a hugely exciting venture for the UK! Building STEP is a very substantial technological challenge but one for which the UK has excellent pedigree and expertise. Additionally, the UK has also associated to the Euratom Research and Training programme, so remains a full participant in the much larger ITER (international fusion project in southern France) and the EUROfusion DEMO powerplant programme, targeting fusion electricity 20 years after ITER begins its first fusion experiments. Whilst STEP and DEMO are comprehensive power plant design programmes driven by net-zero targets, considerable technical uncertainties must still be overcome in parallel. This proof-of-concept proposal, led by the University of Bristol (UoB), partnered with the UKAEA (the government research organisation which leads fusion research in the UK), will seek to address a key technology 'blocker' for fusion power stations: the challenge of monitoring tritium, the radioactive fuel component for fusion energy. Tritium is a weak beta-emitting heavy isotope of hydrogen, with beta radiation energies averaging 5.7keV, meaning that the stopping range of tritium-derived beta particles in detector materials is extremely limited, on the order of microns. There is a need to monitor the abundance of tritium in numerous different parts of a fusion power station from the core, where it is extremely hot) to the breeder blanket (where tritium is created) to the back end separation and storage plants, where cryogenic (very cold) temperatures are used to aid the processes. Hence any detector needs to be able to withstand extremes of temperature and still be able to work in a reliable way.This project will produce the first compact, solid-state detector for tritium, with a unique device structure made from diamond that will make it able to operate in both extreme cold and heat and from very low amounts of tritium to very high amounts of tritium. Developing this device will require development of the materials, with a unique layer on layer growth methodology and also the development of electronics, which can rapidly count the beta particles impinging on the detector. Accordingly this exciting project will involve modelling, material growth, electronic design, device testing and calibration. All towards creating a new type of detector that will be critical to helping a fusion powerplant run.