Wakefields excited in the FCC-ee collimation system

The purpose of this paper is to calculate the longitudinal and transverse wakefields of the FCC collimators using the electromagnetic codes ECHO3D and IW2D. We cross-checked our results using CST particle studio for long bunches, and found them to be in good agreement. The obtained results show that the collimators give one of the highest contributions to the overall FCC-ee wake potentials. In particular, using the code PyHEADTAIL, we have found that the geometric contribution of the collimators' wakefield reduces significantly the transverse mode coupling instability threshold. Therefore, it is imperative to explore and implement solutions that effectively mitigate this wakefield source

Updates on the INFN High Power Ka-band klystron amplifier design program

In the framework of the "Compact Light XLS" project, a short ultra-high gradient linearizer working on the third harmonic of the main linac frequency is requested. Increasing gradients and reducing dimensions are requirements for XLS and all next generation linear accelerators. Actually, ultra-compact normal conducting accelerating structures, operating in the Ka-band regime ranging from 100 to 150 MV/m are required to achieve ultra-high gradients for research, industrial and medical applications. To fulfill these strong requirements, the R&D of a proper Ka-band klystron with RF power output and a high efficiency is mandatory. This contribution reports the design of a possible klystron amplifier tube operating on the TM010 mode at 36 GHz, the third harmonic of the 12 GHz linac frequency, with an efficiency of 42% and a 20 MW RF power output. This contribution discusses also the high-power DC gun, the beam focusing channel and the RF beam dynamics

The Ka-band high power klystron amplifier design program of INFN

In the framework of the Compact Light XLS project, a short ultra-high gradient linearizer working on the third harmonic of the main linac frequency is requested. Increasing gradients and reducing dimensions are requirements for XLS and all next generation linear accelerators. Actually, ultra-compact normal conducting accelerating structures, operating in the Ka-band are required to achieve ultra-high gradients for research, industrial and medical applications, with electric field ranging from 100 to 150 MV/m. To fulfill these strong requirements, the R&D of a proper Ka-band klystron with high RF power output and a high efficiency is mandatory. This contribution reports the design of a possible klystron amplifier tube operating on the 010 mode at 36 GHz, the third harmonic of the 12 GHz linac frequency, with an efficiency of 42% and a 20 MW RF power output. This contribution discusses also the high-power DC gun, the beam focusing channel and the RF beam dynamics

Application of Fractional Operators in Physics and Engineering

In this paper we present a solution to a fractional integral of order 3/2 with the use of fractional Cauchy-like integral formula. The integral arises during the solution of BiotSavart equation to find the exact analytical solution for the magnetic field components of a solenoid. The integrals are computed by cutting the branch line in order to have an analytic function inside the integral instead of multi-valued operation

Studies of FCC-ee single bunch Instabilities with an updated impedance model

The design of the FCC-ee collider is ongoing with the goal of optimizing beam parameters and developing various accelerator systems. As a result, the modelling of coupling impedance is continuously evolving to take into account the design of the collider vacuum chamber and hardware components. Concurrently, estimates of collective effects and instabilities are being continually updated and refined. This paper presents the current FCC-ee impedance model and reports the findings of the single-bunch instability studies. Additionally, some potential mitigation techniques for these instabilities are discussed

Electron Gun and Magnetic Systems Studies for a 36 GHz Klystron Amplifier

Self consistent analytic and numeric design for a set of innovative electron guns suitable for Ka-band klystrons is proposed in this paper. The proposed electron sources are designed to produces narrow beam with high currents that can be used in devices with critical dimensions. The proposed set of electron gun is destined to high power klystrons to be used as power sources for accelerating structures operating in Ka-Band. This family of accelerators is foreseen to achieve energy gradients around 150 MV/m. A klystron amplifier is being investigated in order to feed a linearizer structure. In this paper different electron gun and beam focusing channel designs are presented

Multiphysics Design of High-Power Microwave Vacuum Window

This paper presents the Multiphysics Analysis of a High- Power Microwave Window for a Ka-Band Klystron providing 16MW of peak power. After the optimization of the electromagnetic performances, we analyze the effect of RF heating effect and the stress of the pressure on the window. We also analyze the multipactor effect, that is a common cause of window failure. Using such approach, it is possible to realize a virtual prototype capable to represent in a complete way the real prototype to be manufactured