Beam size and position measurement based on logarithm processing algorithm in HLS II

TL;DR

This paper introduces a logarithm processing algorithm for measuring beam size and position in HLS II, demonstrating accurate results through simulation, calibration, and experimental verification with a multianode photomultiplier tube.

Contribution

The paper presents a novel logarithm processing algorithm for beam measurement using only four channels of a MAPMT, validated through simulation and experimental data in HLS II.

Findings

Measured beam size and position match simulation after calibration.

The algorithm accurately determines the vertical tune with a fractional part of 0.3628.

Experimental results confirm the effectiveness of the proposed method.

Abstract

A logarithm processing algorithm to measure beam transverse size and position is proposed and preliminary experimental results in Hefei Light Source II (HLS II) are given. The algorithm is based on only 4 successive channels of 16 anode channels of multianode photomultiplier tube (MAPMT) R5900U-00-L16 which has typical rise time of 0.6 ns and effective area of 0.8x16 mm for a single anode channel. In the paper, we firstly elaborate the simulation results of the algorithm with and without channel inconsistency. Then we calibrate the channel inconsistency and verify the algorithm using general current signal processor Libera Photon in low-speed scheme. Finally we get turn-by-turn beam size and position and calculate the vertical tune in high-speed scheme. The experimental results show that measured values fit well with simulation results after channel differences are calibrated and the fractional part of the tune in vertical direction is 0.3628 which is very close to the nominal value 0.3621.