Arachnid - A next generation silicon pixel detector for Particle and Nuclear Physics

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


Three experimental communities have been brought together in order to make a single streamlined and cost-effective proposal centred on world leading CMOS Monolithic Active Pixel Sensor technology that has been developed in the UK. This proposal is focussed on validating the use of cheap state of the art CMOS pixel sensors in nuclear and particle physics applications. CMOS is an industry standard technology used by large chip manufactures such as Intel, and by using state of the art commercial technology in scientific applications we aim to change the way that many particle detectors are made. Implications of this would include a reduction in cost of future particle and nuclear physics experiments by replacing traditionally more expensive devices with the significantly cheaper CMOS technology. In order to do this we need to characterise existing devices in terms of their response to radiation, and also determine the operational limits, i.e. how much radiation we can expose the devices to before the fail.

This proposal also has a number of specialist application tests in order to understand the operational envelop of these devices in terms of temperature and magnetic field. The limits to which one can reduce a silicon sensor to a thin film for sensing applications will also be explored to follow up on preliminary feasibility studies that have already been completed successfully. Thin film devices could revolutionise the design and performance of low mass tracking devices where that is a requirement for specialist scientific applications.

In terms of impact and innovation, we also aim to demonstrate the ability to deposit thin film coatings to sensors so that one can tailor make a device to respond to different energy radiation (soft or hard X-rays, UV light and so on). Such devices would have imaging applications in astronomy, medicine and other industries. UV sensitive devices operating at low temperatures would also be of special interest for future neutrino experiments that are in the very early planning stages (T2K upgrade).

By the end of this proposal period we aim to have characterised the operation limits of these sensors in terms of radiation hardness, temperature and magnetic field environments, and to have designed a viable chip that can be used as a prototype for a real world experiment. Taking us a step closer to cheaper large-scale silicon based scientific instruments with higher performance. At the same time we will have a much clearer understanding of the limits of this technology for commercial and scientific applications beyond the remit of the particle and nuclear physics applications that are the core motivation for this research.

The research we are doing should help reduce the capital cost of investment in future experimental activities that could be built using CMOS MAPS as a cheaper and better performing alternative to traditional technologies. In a nutshell this proposal is an investment into doing more science better and cheaper in the future.

Planned Impact

The work described in this grant will result in the UK groups involved maintaining and enhancing their world-leading expertise in the development of Monolithic Active Pixel Sensors. In addition to the applications in nuclear and particle physics discussed in the proposal, these devices hold great promise for diverse areas from astronomy to various imaging applications. The groups will actively pursue links with industry to exploit any potential applications. We already have a significant track record in this area, current industrial links including GE Health care, BAE systems, AWE, Centronic, Kromek, Canberra Harwell UK, Ametek (Ortec), John Caunt Scientific and Rapiscan. We expect to continue this work with the help of the Universities and STFC technology transfer offices. For example, RAL PPD has recently created a New Detector Initiatives group to exploit STFC technology for the STFC Futures program including health care and environment. In addition, the Innovation Office at QMUL has already expressed strong interest in this proposal and intend to look for ways to take any viable technology a step closer to a marketable product, especially in applications related to the medical industry. A possible collaboration with the Royal London and Barts hospitals that are associated with the College School of Medicine and Dentistry has already been indicated. Finally, the project will provide opportunities for training of PhD students and PDRAs in frontier areas of Si, FEE, FPGA and DAQ development. This results in trained manpower in these areas which is great demand by UK industry.


10 25 50
Description We were able to establish that the Cherwell chip functioned - and have produced resolution measurements for this device for reference pixels and other pixel variants. We also managed to produce preliminary results on the "strixel" concept of embedding signal processing circuitry in the column of pixels being read out.

This work fed into the RAL/CERN ALICE CMOS chip design and has resulted in moving the field forward so that ALICE has now adopted CMOS MAPS as a technology for the ITS upgrade.

This work has also attracted interest from the other LHC upgrades.

We are in the process of preparing a publication to summarise the results.

We have reported results at seminars, conferences and workshops.
Exploitation Route The research has a number of potential aspects of interest beyond particle physics. These potential use cases include radiation detection aspects in the energy industry and for security purposes, and further study is required to raise the proven concepts to the appropriate TRL to explore industry liaison in some form.

Now working with Micron Semiconductor Ltd. on issues related to this project.
Sectors Environment,Security and Diplomacy,Other

Description Infrastructure Funding (PAR)
Amount £161,000 (GBP)
Organisation Queen Mary University of London 
Sector Academic/University
Country United Kingdom
Start 08/2016 
End 07/2017
Description Innovation Fund
Amount £10,000 (GBP)
Organisation Queen Mary University of London 
Sector Academic/University
Country United Kingdom
Start 08/2016 
End 01/2017