Detectors needed by particle physics experiments have to withstand huge radiation doses and work for many years. As accelerators become able to reach higher energies and create more and more collisions per second, the requirements for detectors to survive inside the experiments becomes highly challenging. At the moment, the best option for high speed, radiation hard position sensitive detectors is to use segmented silicon. For the volume of the experiment where charged tracks need to be reconstructed as they bend in a high magnetic field, large areas of detectors measuring the particle trajectories to hundredth of a millimeter precision are needed. While we know how to do this with silicon and the LHC experiments ATLAS and CMS have silicon trackers of 60m2 and 200m2 area respectively, we do not know how to build arrays of these areas suitable for ten times the expected dose at the LHC. This is exactly the requirement of the Super-LHC which will operate with an average collision rate ten times that of the LHC. The proposal is a novel approach to building detectors affordably that can meet these demands. it builds on experience at Liverpool in making smaller detector systems able to cope with these very high doses and proposes to explore processing tricks developed for other radiation environments by e2v to come up with a robust method for making the large quantitities of silicon microstrip detectors required for the SLHC.

THz technology is a very new and exciting frontier in science and engineering. A vast number of potential applications ranging from superior high resolution RADAR systems for both military and civilian use to medical diagnostic aids for treatment of bed sores, skin cancer and burns, wireless office communications and even archaeological and astronomical applications have been proposed. The medical applications are particularly exciting and are attracting much media attention, THz radiation having already been dubbed T-Rays by the press.This project proposes the development of just such a source of THz radiation - a novel form of Planar Gunn diode. This device has already been physically realized and a patent application (No. 0608515.3) filed (under a Scottish Enterprise Proof of Concept award). This grant proposal seeks to develop the full potential of the device, exploring and exploiting its unusual geometry which makes it ideally suited to integration in MMIC circuitry in contrast to conventional Gunn diodes, increasing its power and developing the technology to the point where it will be taken up by British industry.

The e2v Centre for Electronic Imaging as a collaboration between e2v and the Open University to provide training for young scientists and engineers in the field of imaging detectors for science experiments. e2v have agreed to fund up to a rolling 12 PhD CASE students as part of this collaboration, which represents one of the largest concentrations of industrially-sponsored students under the CASE scheme. At a meeting with the PPARC executive in 2004 (involving Ian Halliday and Richard Wade), the research council agreed to support this ambitious plan for PhD student training. This single application is one of 3 CASE applications proposed into the 2009 round, exploring different aspects of imaging semiconductor device R&D of relevance to STFC science. Under our STFC Gaia grant, we have recently been using the Silvaco 3D device modelling software package to help in the European effort aimed at understanding the effect of space radiation daage in the CCDs. Using this software we are producing an accurate description of the pixels in the Gaia CCDs to inform how the charge is stored in the pixel as a function of signal size. This information, in particular the signal density distribution, is then used to calculate charge trapping times in the presence of prton-induced traps, and through Monte Carlo models the impact of the spce radiation on the CTE. This work is demonstrating that such modelling (in this istance using Silvaco) can provide a very poweful tool in the understanding of pixel structures, particularly when feature sizes become comparable to the fringing fields in the device (<5 microns). Our work on Gaia indicated a protential problem with one of the implants in the CCDs, which has subsequently been backed-up by measurements. Had the modelling technique been available at the time of design, then the customised Gaia CCDs could have been improved in performance yielding better sensitivity in the Gaia data products. Here we propose a PhD CASE studentship which will perform advanced modelling in 3D of CCD and CMOS pixel designs to aid understanding of the detailed movement of signal charge within the detectors leading to improvements in future imager designs. To help ensure that the modelling work and its results are accurate, we will specify test structures based on the early modelling which will then be designed and fabricated by e2v. These test structures will then be evaluated, and the results used to benchmark and validate the output from the model. The student will work on both traditional CCD device structures, plus the newer CONS Active Pixel Structure (APS) imagers currently being developed by e2v. One of the trends in scientific imagers is toward large imaging arrays having smaller pixels. As mentioned above, when the feature sizes become less than around 5 microns, the devices are subject to non-linear effects arising from the 'narrow channel effect'. For such large area/small pixel devices in the future, a thorough understanding of their detailed operation will become increasingly important. By the end of the studentship we would anticipate that a much greater understanding is obtained into the details of charge storage and movement within CCD and CMOS structures with the creation of new 'design rules' to help the designers create new cutting-edge sensors with improved performance.

The purpose of this project is to research, develop and demonstrate optimal design methodologies for high voltage, high frequency transformers for use in switching converters. The project will allow for commercial exploitation of a new generation of high frequency, high voltage switching converter for industrial and physics research applications.

The Klystron is a well-known, high efficiency amplifier, with a simple structure and scalable dimensions. It is typically designed with cylindrical reentrant cavities in the fundamental mode. However as the frequency of the device increases the size of the structure decreases. At mm-wave frequencies this leads to two problems: 1) Manufacturing the complex small scale structures. 2) The gap voltage decreases as the gap gets shorter leading to less gain. Most mm-wave klystron concepts reported in the literature are simply smaller versions of microwave klystrons. Even if, in principle the dimensions can be scaled according to the frequency increase, the fabrication challenges and the beam characteristic represent a huge obstacle to the realization of a working device when frequency is higher than 50 GHz. This is consequently true for the frequency range around 94 GHz, which is of great interest for communication and radar applications. This proposal is aimed to overcome of the above-mentioned obstacle to the design and realization of a 94 GHz klystron by two innovative design solutions. The first solution is to operate the cavity at a higher order mode, chosen with similar Ez field distribution on the gap cross-section as the fundamental mode. The design will adopt reentrant cavities with square or rectangular shape, to be compatible with a photolithographic fabrication technique. The higher mode operation permits to design the cavities with dimensions larger (at least 4 -5 times) than in case of fundamental mode operation. This eases the technological effort and makes possible a high quality fabrication by mechanical micromachining or by photolithographic processes. Further, the beam tunnel can be larger than in fundamental mode, to support higher beam current. In order to increase the interaction a number of intermediate buncher cavities, spaced all along the drift tube, will be used to increase the beam current modulation. A separate approach uses a lower frequency input cavity to modulate the beam current. As the beam travels down the drift tube beam harmonics start to form hence a higher order mode output cavity at an integer harmonic frequency of the input cavity can be exited hence acting as a high power frequency multiplier. As the input can be a readily available high power microwave source we are able to overcome the low gain of the device.