Towards a commercial prototype for Cosmic Ray Tomography

鉴于近年来西方城市遭受恐怖袭击，国家核安全是当前的热门话题。对恶意的非国家行为者可能对我国发动核攻击的担忧是真实存在的。为了阻止这些材料进入英国，计划对所有汽车和货物集装箱进行扫描。最好的扫描技术是宇宙射线断层扫描(CRT)。这是因为宇宙中的缪子具有很强的穿透性，是自然产生的，并且具有很高的比率。这意味着不可能屏蔽，因为没有引入高于背景的辐射，所以在扫描期间不能触发设备。从2009年11月开始，我们成功地建立了基于高分辨率电阻板室的宇宙射线层析成像系统。这个迷你管道项目非常成功。现在可行性研究已经完成，我们需要进行下一步工作，研究生产适合商业开发的RPC系统的主要问题。下一步要做的主要问题是：最大条带长度、减少读出通道的数量和密封RPC。在本项目中，我们将重点放在读出芯片的减少上。为了减少它们的数量，我们将研究电容耦合浮动条的电势。这些条带不连接到读出芯片，但与邻居共享电荷，直到与连接到读出芯片的邻居共享电荷。这是硅探测器中众所周知的“技巧”，我们想要研究我们的探测器系统的潜力。这将使基于RPC的系统的构建成本大大降低。这项提议的完成将使我们的合作能够将STFC开发的技术商业化，造福于英国工业。

National nuclear security is currently a hot topic in light of terrorist attacks on Western cities in recent years. The fear that a non-state actor with malicious intent could commence a nuclear attack on our nation is real. To stop these materials entering the UK, the plan is to scan all cars and cargo containers. The best technique for scanning is cosmic ray tomography (CRT). This is because cosmic muons are highly penetrating, are naturally occurring and have a high rate. This means that it is impossible to screen against and since no above-background radiation is introduced one cannot trigger the device during the scan.Starting November 2009 we have successfully built a Cosmic Ray Tomography system based on high resolution resistive plate chambers. This mini-PIPPS project has been very successful. Now that the feasibility study is complete, we need to make the next step and study the main issues for producing an RPC system suitable for commercial exploitation. The main issues to make that next step are: the maximum strip length, reduction of the number of read out channels and sealing the RPCs. In this project we focus on the reduction of readout chips. To reduce their number we will study the potential of capacitively coupled floating strips. These strips are not connected to the readout chips, but share their charge with their neighbors until the charge is shared with a neighbor that is connected to the readout chip. This is a well-known "trick" in silicon detectors and we want to study the potential for our detector systems. This will make RPC-based systems significantly cheaper to build. Completion of this proposal will allow our collaboration to commercially exploit STFC developed technology for the benefit of UK industry.