Chikhi Nassim, Passarelli Andrea, Andreone Antonello, Masullo Maria Rosaria
Physics Department, University of Naples "Federico II", Naples, 80126, Italy.
INFN Naples Unit, Naples, 80126, Italy.
Sci Rep. 2020 Nov 9;10(1):19352. doi: 10.1038/s41598-020-76433-3.
In many resonant structures the damping of parasitic or higher order modes is indispensable to guarantee a correct and stable performance. This is particularly true in the microwave region in case of cavities or other resonant systems operating in accelerating structures, where the mitigation of spurious resonance effects is mandatory to achieve high quality particle beams. We present the results on the mode suppression in a real pillbox cavity by inserting a properly designed pyramidal metamaterial that acts as light, small volume damper for specific resonances in the range 3-4 GHz, only slightly perturbing other intrinsic modes. Measurements of the cavity response without and with the metamaterial absorber are presented and compared with full wave simulations. Field distribution for the pillbox intrinsic modes under scrutiny is also presented, showing that damping induced by the metamaterial critically depends on its relative position inside the cavity.
在许多谐振结构中，寄生或高阶模式的阻尼对于确保正确且稳定的性能是必不可少的。在微波区域，对于在加速结构中运行的腔体或其他谐振系统而言尤其如此，在这种情况下，减轻杂散共振效应对于获得高质量粒子束是必不可少的。我们展示了通过插入精心设计的金字塔形超材料来抑制真实药盒形腔体中模式的结果，该超材料对于3 - 4吉赫兹范围内的特定共振起到轻量级、小体积的阻尼作用，仅对其他固有模式产生轻微扰动。给出了有无超材料吸收器时腔体响应的测量结果，并与全波模拟进行了比较。还给出了所研究的药盒形腔体固有模式的场分布，表明超材料引起的阻尼严重依赖于其在腔内的相对位置。
