Pushing the Gradient Frontier in Superconducting RF

射频超导已经成为核物理、材料科学和高能物理前沿研究所必需的各种加速器的使能技术。在美国，许多加速器设施都是基于超导射频（SRF）技术。随着SRF梯度性能的不断提高，其新应用前景越来越有吸引力。本提案旨在继续改进超导腔梯度的通用研发。在过去的十年中，由于对腔性能限制的物理理解的改进以及解决这些限制的适当治疗方法的发明，铌超导腔中的梯度一直在稳步推进。该方案旨在将记录梯度扩展到新形状的多细胞结构。该提案的智力价值在于了解全尺寸结构中良率限制的原因，为实现60 MV/m梯度扫清了道路。这里提出的通用进展的广泛影响将使许多基于SRF的新设施受益：自由电子激光器，基于能量回收直线加速器的光源，用于中微子束线或用于核废料加速器嬗变的高强度质子加速器，用于核天体物理学的稀有同位素加速器，国际线性对撞机，中微子工厂的μ子加速器以及最终的多tev μ子对撞机。

Radio Frequency Superconductivity has become an enabling technology for a variety of accelerators necessary for frontier research in nuclear physics, materials science and high energy physics. In the US, many accelerator facilities are firmly based on superconducting rf (SRF) technology. As the gradient capability of SRF continues to improve, prospects for new applications grow increasingly attractive. This proposal seeks to continue generic R&D on improving superconducting cavity gradients. Gradients in niobium superconducting cavities have been steadily advancing over the last decade due to improvements in understanding the physics of cavity performance limitations and due to invention of appropriate cures to address these limitations. This proposal seeks to extend the record gradients to multi-cell structures of new shapes.The intellectual merit of this proposal will be to understand the causes of yield limitations in full-scale structures clearing the path to realizing 60 MV/m gradients. The broad impact of generic advances proposed here would be to benefit many of new facilities that will be based on SRF: Free Electron Lasers, Energy Recovery Linac based light sources, high intensity proton accelerators for neutrino beam lines or for accelerator transmutation of nuclear waste, rare isotope accelerators for nuclear astrophysics, the International Linear Collider, Muon accelerators for neutrino factories and ultimately a multi-TeV muon collider.