Zero (support) Mass detector development (ZMD)

Lead Research Organisation: Queen Mary, University of London
Department Name: Physics


The ZMD programme aims to make novel silicon detector module prototypes using ultra thin silicon.
In particle physics detectors like those at the Large Hadron Collider, silicon detector layers pinpoint the location of charged particles as they pass on curved paths through the detector. By "connecting the dots" from such measurements, the momentum of such particles is measured. But the more material is used in such detectors, and particularly in their support structures, the more likely particles are to be deflected, reducing the precision of the measurement. This problem can be solved by new technology, such as ZMD, that will reduce the mas of silicon detector layers.
There are two main steps achieve this: the first is to thin the silicon, and the second is to support the thin material by imposing stress in the crystal. Fortunately, by curving the silicon sensor we can make it self-supporting to a significant degree, while doing minimal damaging to its overall properties.

This work follows on from the Arachnid WP3 programme, and builds on expertise developed for the ATLAS ITk project at Queen Mary University of London.

A successful outcome of this programme could lead to a significant reduction in radiation length of silicon trackers. This will translate into improved measurements of charged particle tracks; in turn leading to an improvement to measurements made in particle physics. A natural consequence of this work will be a much deeper understanding of the shape of silicon sensors and modules in detectors that will inform the design of alignment algorithms and future tracking systems. This in turn will lead to the potential for significant improvements in physics performance for next generation tracking systems.

We will work closely with a UK company, Micron Semiconductor Ltd., in developing this technology, and our success in developing this new technology will have a significant impact on their business and potentially other UK companies as well.

Planned Impact

We will work with the UK company Micron Semiconductor Ltd. (MSL) on a number of technological challenges in using ultra thin silicon for detectors. Techniques developed for handling these devices and data from the research will inform us how to construct new types of detectors and understand how the surface stresses between different materials affect charge readout and affect signals. This will feed back into refined design and may be of interest to the electronics industry. We hope in the long term that this work will lead to an IPS or knowledge transfer partnership between MSL and the QMUL team in order to enable MSL to manufacture new types of device for scientific and other types of application. See MSL's letter of support; note they have previously invested 100k in-kind contribution to this work.

Work done will be relevant for other stakeholders who manufacture imaging sensors and silicon detectors, e.g. EEV (UK company). Spherical deformation of sensors is of interest for camera companies (and telescopes). We have had preliminary discussions with Specialised Imaging (UK company) and will be able to follow up with them to discuss collaboration given positive results from this programme of work.

The use of curved detectors some medical devices would have some advantages over conventional routes. We will explore the potential interest in cylindrical (or arc shaped) ZMD detectors using industrial contacts at one of the hospitals associated with QMUL in order to engage with that potential stakeholder group.

We plan to explore the potential interest in cylindrical detectors for various commercial applications toward the end of the testing phase of the project and will do so in conjunction with the QMUL business development and innovations teams. We have been working with those teams for the past few years and have developed an understanding of how to approach the issue of outreach and the in-house protocols governing this area of operation. There is a direct link with MSL established at this stage, we will consult with other external stakeholders to gauge the potential for broader impact if doing so would not affect the MSL connection or industrial interest.

For any detector system, it is critical to verify that one can run a system over a long period of time. When this programme ends we aim to have a test system that can provide a stand-alone test capability and will explore the possibility of using this test detector in some further context using contacts at RAL, LAL, LNF to explore the possibility of deployment into some specific experiments related to machine physics. In the case of a lack of interest in these areas we would deploy the system to accumulate cosmic data over time at QMUL and use this to monitor performance changes with time. This work can impact upon the way we make low mass tracking devices, which in turn can be used in STFC funded science, biosciences, and by light source users. This in turn could impact upon future energy frontier precision Higgs and new particle search programmes. We have the ability to affect the scientific outputs of those routes by reducing the measurement resolution component coming from the solid-state detector used in those applications.

At QMUL we have a long-standing tradition of public engagement and outreach, particularly with the local community. We have established outreach arms within the College and School who arrange many events. In addition to the usual things, such as presence at the Big Bang fair, running master classes, speaking to 6th form students and so on we have a strong track record in the School of Physics and Astronomy for doing that that little bit extra. The SPA at QMUL work with the Institute for Research in Schools, award winning artists and the local community to ensure outreach is truly embedded in our culture.


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