Advanced electron beam gun design for high integrity processing

电子束技术是一种独特的技术，它能够将不同的、否则难以焊接的金属与非常精确和干净的焊缝连接在一起，同时将工作区域以外的材料加热降至最低。近年来，在添加剂制造中使用该技术已成为一个令人兴奋的机会，因为这将降低该技术的运营成本，并提高其通用性和性能。现有技术的一个缺点是传统热离子电子源的热响应速度慢、寿命短，这阻碍了电子束技术在添加剂制造应用中的开发。在这个项目中，我们将研究使用等离子体阴极代替热电子发射作为电子源，以克服这些限制。学生将从事实验和计算工作，以设计、制造和表征不同的等离子体阴极，同时评估它们作为电子枪电子源的可行性。由于电子枪必须工作的压力范围，对等离子体的建模将需要使用动力学方法，预计将在研究中使用粒子-单元蒙特卡罗碰撞模型。

Electron beam technology is a unique technology that enables joining dissimilar and otherwise hard to weld metals with very precise and clean welds while minimizing the heating of the material outside the working area. In recent years, the use of this technology in additive manufacturing has become an exciting opportunity as this would reduce the operational cost of the technology and improve its versatility and performance. A shortcoming of the current technology is the slow thermal response and short lifetime of conventional thermionic electron sources, which hinders the exploitation of electron beam technology in additive manufacturing applications. In this project we will investigate the use of a plasma cathode instead of thermionic emission as a source of electrons to overcome these limitations. The student will be undertaking experimental and computational work to design, fabricate and characterise different plasma cathodes while assessing their feasibility as electron sources for electron guns. Due to the pressure range at which the electron gun must operate at, modelling of the plasma will require the use of a kinetic approach and it is anticipated that a Particle-in-cell Monte Carlo collision model will be used in the study.