Cusp electron beam source for terahertz gyro-amplifier

Standoff, real time video rate high resolution imaging and sensing of conceived contrabands such as weapons, explosives, drugs, chemical and biological materials are hampered by the lack of high power sources and especially broadband amplifiers of terahertz radiation. The gyro-amplifiers based on a recent technological breakthrough at the University of Strathclyde offer a unique opportunity to fill this long standing technology gap and promise amplification with an unprecedented 10% instantaneous bandwidth and an unrivalled, 100 and 200 W respectively for 625 and 400 GHz (W He et al PRL 2013, 110, art 165101, 2013). Such a source will also improve the sensitivity by many orders of magnitude of Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI) through (DNP) techniques and enable high field pulse EPR (for materials and biomolecular characterisation). The EPR and DNP enhanced NMR (including the possibility of pulsed DNP-NMR and the use of phase and amplitude modulation) experiments will give rise to absolutely world-leading research. It will strongly enhance the UK's position as a world leader in a wide range of academic research areas, including physics, chemistry, biology, engineering and medicine.

As well as for EPR and DNP these sources are also of interest in magnetically confined fusion for use in plasma diagnostics. Because the amplifiers have wide instantaneous bandwidth they may be adjusted dynamically to a wider range of plasma parameters, in comparison to a single frequency source technique.

The gyro-TWA would be an ideal source for cloud profiling radar and the detection of atmospheric pollutants because the atmospheric absorption, penetration and scattering losses, practical stand-off systems require considerable power, typically hundreds of watts. Other applications include high frequency long range security imaging, space situational awareness (detecting space debris), terrain mapping (volcano monitoring), radar jamming (of guided missiles) and long range, high bandwidth, line of sight communications, real time video-rate detection of hidden explosives and illegal drugs.

The gyro-TWA is also an ideal source for quantum computing based on electron spin qubits. A world-leading example of emerging quantum technology is the coherent use of the electron spin associated with a nitrogen-vacancy (NV) centre in diamond. To obtain enough spectral resolution it requires fast coherent control of the NV electron spin with a high-power (hundreds Watts), high frequency (hundreds GHz) at a high magnetic field.

We believe the proposal has the potential to create impact on an academic, societal and economic level as well as contributing to the training and career advancement of future research leaders in an important technology area.

The gyro-TWA is a technology with potential for high societal impact on a large number of themes, with strong public recognition, such as 1) security and safety of society: real time security imaging (through clothes and bags) for contrabands such as explosives, illegal drugs, long range high resolution radar imaging of invading flying objects or space debris; 2). well-being and longevity of society: through its high sensitivity NMR and MRI as methods of biomarkers, imaging and medicine discovery for large numbers of diseases including cancers; 3) better environment and weather predictions: monitoring of volcanic ash, cloud and pollutant profiling 4) next generation energy sources: through its plasma diagnostic capability and 5) fast information processing: through quantum computing based on electron spin qubits.

It has huge economic impacts through our links with TMD Ltd, (switched mode power supply manufacturers), e2v Ltd (vacuum tube manufacturers), Teratech (terahertz imaging and sensing components), Thomas Keating Ltd (spectrometer and EPR instrumentation) and through academic colleagues in the fields of terahertz imaging and sensing applications, and hence to further social impacts due to the pull-through to security. There are also important, significant applications for these terahertz amplifiers in NMR, EPR, medical imaging, radar and material characterisation.