SHeet Electron beam vacuum eLectronic Devices for the generation of hIGH power THz radiation

THz频率（300 GHz至1 THz）辐射源用于许多不同的应用，例如雷达，材料基本特性的研究，安全成像，磁共振光谱，等离子体诊断，医学成像和化学传感。可以从数百GHz到THz频率范围内的“台式”自由电子辐射源产生的功率受到以下事实的限制：随着频率的增加，必须减小相互作用区域的尺寸，以防止微波激射器变得过模，这导致输出辐射的时间或空间相干性的损失。随着频率的增加，使用传统的电子阴极来聚焦和形成高电流密度、高质量的电子束通过太赫兹脉泽的小尺寸相互作用区域变得越来越困难（如果不是不可能的话）。赝火花等离子体阴极可以克服由电子发射施加的电流密度限制，并且能够在不需要使用外部磁场的情况下产生片状电子束。一个psuedospark-sourced片状电子束将被用来功率平面扩展相互作用速调管放大器（EIKA），这是在一个方向上扩展相比，传统的EIKA的基础上的圆柱形电子束产生的阴极。由固态源产生的12 mW、365 GHz的信号经赝火花片注平面扩展互作用速调管放大器（PS-EIKA）放大到100 W。由于不需要引导磁场，PS-EIKA将是紧凑、可靠、鲁棒的，并且可以在高（kHz）脉冲重复频率下产生100 ns持续时间的脉冲。此外，赝火花源片状电子束将用于驱动平面扩展相互作用振荡器（EIKO），以在1 THz产生10 W的输出功率。拟议的研究将由两个领先的研究小组在微波器件工程与互补的专业知识，在斯特拉斯克莱德大学和QMUL联合进行。赝火花扩展相互作用速调管放大器（PS-EIKA）和振荡器的设计和建设的知识将转移到我们的项目合作伙伴。将建立一个太赫兹放大器用户在磁共振光谱，等离子体诊断和毫米波雷达应用的社区网络，以利于未来共同创建的研究合作。这些包括在电子顺磁共振（EPR）中使用PS-EIKA，并通过DNP技术将核磁共振（NMR）的灵敏度提高许多数量级。EPR和DNP增强NMR（包括脉冲DNP NMR的可能性以及相位和幅度调制的使用）实验将有力地提高英国在物理，化学，生物学，工程和医学等广泛学术研究领域的世界领先地位。这些源在用于等离子体诊断和毫米波雷达系统的磁约束聚变领域也具有国家和国际重要性，将建造新的高功率亚毫米波放大器和太赫兹振荡器，以从根本上提高核磁共振/DNP和EPR仪器在强磁场中的灵敏度，增强等离子体诊断和太赫兹成像。作为提案的一部分，网络活动将汇集磁共振光谱学、微波等离子体诊断界以及高功率放大器和微波/毫米波源界的领先团体/行业。通过我们的项目合作伙伴，将利用这些领域的能力以及使用亚毫米波雷达测量快速和慢速移动物体的能力。所有网络成员在相关技术和方法开发方面都有出色的记录，并且都与国家和国际应用程序有着密切的联系，在射频和微波科学技术应用领域有多个合作者。

THz frequency (300GHz to 1THz) radiation sources are used in a number of diverse applications such as radars, the study of the fundamental properties of materials, security imaging, magnetic resonance spectroscopy, plasma diagnostics, medical imaging and chemical sensing. The power that can be generated from 'bench top' free electron radiation sources in the hundreds of GHz to THz frequency range has been limited by the fact that as the frequency is increased, the size of the interaction region has to be reduced in order to prevent the maser becoming overmoded which results in a loss of the temporal or spatial coherence of the output radiation. As the frequency increases it becomes increasingly difficult (if not impossible) using conventional thermionic cathodes to focus and form high current density, high quality electron beams through the small size interaction region of the THz maser. A pseudospark plasma cathode can overcome current density limitations imposed by thermionic emission as well as being able to generate a sheet electron beam without the need to use an external magnetic field. A psuedospark-sourced sheet electron beam will be used to power a planar Extended Interaction Klystron Amplifier (EIKA) which is extended in one direction as compared to conventional EIKAs based on a cylindrical electron beam produced by a thermionic cathode. A 12mW, 365GHz signal generated by a solid state source will amplified to 100W by the Pseudospark Sheet beam planar Extended Interaction Klystron Amplifier (PS-EIKA). As no guide magnetic field is required the PS-EIKA will be compact, reliable, robust and can generate 100ns duration pulses at high (kHz) pulse repetition frequencies. In addition a pseudospark source sheet electron beam will be used to drive a planar Extended Interaction Oscillator (EIKO) to generate 10W of output power at 1THz. The proposed research will be conducted jointly by two leading research groups in microwave device engineering with complementary expertise, in Univ. of Strathclyde and QMUL.Knowledge of pseudospark Extended Interaction Klystron amplifier (PS-EIKA) and oscillator design and construction will be transferred to our Project Partner. A community network of THz amplifier users in magnetic resonance spectroscopy, plasma diagnostics and mm-wave radar applications will be built up to the benefit of future co-created research collaborations. These include the use of the PS-EIKA in Electron Paramagnetic Resonance (EPR) and to improve the sensitivity by many orders of magnitude of Nuclear Magnetic Resonance (NMR) through DNP techniques. The EPR and DNP enhanced NMR (including the possibility of pulsed DNP-NMR and the use of phase and amplitude modulation) experiments will strongly enhance the UK's position as a world leader in a wide range of academic research areas in physics, chemistry, biology, engineering and medicine. These sources are also of national and international importance in the areas of magnetically confined fusion for plasma diagnostics and mm-wave radar systems.New high power sub-millimetre wave amplifiers and terahertz oscillators will be constructed for radically improved sensitivities in NMR/DNP and EPR instruments in high magnetic fields, enhanced plasma diagnostics and THz imaging. Network activities as part of the proposal will bring together leading groups/industries in the magnetic resonance spectroscopy, microwave plasma diagnostics community and the high power amplifier and microwave/mm-wave source community. Increased capability in these areas as well as enhanced capability to measure fast and slow moving objects using sub-millimetre wave radars will be exploited via our Project Partner. All network members have an outstanding track record in relevant technology and methodology development and all have strong links with National and International applications programs with multiple collaborators across RF and Microwave science and technology application areas.