Simulation of BPM and DC-monitor assembly for the NESTOR storage ring by CST Studio Suite

TL;DR

This paper simulates the NESTOR storage ring's vacuum chamber components, including the BPM and DC-monitor assembly, using CST Studio Suite to estimate their electromagnetic impedance contributions and frequency content.

Contribution

It provides detailed simulation-based estimates of impedance and loss factors for NESTOR ring components, including the BPM and DC-monitor assembly, which were previously not characterized.

Findings

Impedance contribution of the assembly is 0.71 Ohm for Z/n.

Loss factor is estimated at 0.21 V/pC.

Frequency content analyzed up to 16 GHz.

Abstract

The piece of NESTOR vacuum chamber with the ceramic insertion for DC-monitor and RF-shields was simulated by using both transient and wake field solvers of CST Studio Suite. For a 6 mm gap between two RF-shields the contributions of the assembly considered to the longitudinal broadband (BB) impedance Z/n and the loss factor kloss are 0.71 Ohm and 0.21 V/pC, correspondingly. These estimates are the second largest after those of the RF-cavity that were obtained till now for the NESTOR ring components. Contributions from a beam position monitor (BPM) are also obtained by simulation and compared with analytical estimates obtained earlier. We also present in the paper the frequency content of longitudinal impedance in the frequency range from 0 to 16 GHz for all ring components considered.