Beam position monitor design for the High Energy Photon Source

Abstract

A button and stripline beam position monitor (BPM) were designed and developed to achieve sub-micron orbit stability in the High Energy Photon Source (HEPS). Analytical formulae and CST electromagnetic simulation software were used to calculate the radio frequency characteristics of the BPM. The BPM design procedure was developed according to the HEPS requirements. The characteristic impedances of the stripline were designed to be 50 Ω and confirmed by measurements. The position sensitivity, position resolution, capacitance, and wakefield impedance of the button BPM were calculated. The measurement results confirmed that the design satisfied the HEPS requirements.

Capacitive BPM electromagnetic design optimisation

“…The most impactful higherorder mode excited by the beam is the TE 110 -like mode with respect to the button axis, and its frequency increases with the decrease in the diameter of the button. Figure 4 shows the result obtained in the 0−5 GHz frequency range for transfer impedance [15,16,17]. As it can be seen in Figs.…”