Performance of a Downconverter Test-electronics with MTCA-based Digitizers for Beam Position Monitoring in 3.9 GHz Accelerating Cavities

TL;DR

This paper evaluates the performance of a downconverter test-electronics system combined with MTCA-based digitizers for beam position monitoring in 3.9 GHz accelerating cavities, focusing on signal conversion and digitizer comparison.

Contribution

It provides a performance analysis of MTCA-based digitizers with downconverter electronics for HOM signal processing in accelerator environments.

Findings

Successful conversion of HOM signals to 70MHz IF

MTCA digitizer performance comparable to VME digitizer

Insights into undersampling effects at 108MS/s

Abstract

Beam-excited higher order modes (HOM) in 3.9GHz accelerating cavities are planned to be used for beam position monitoring at the European XFEL. The selected HOMs are located around 5440MHz, with a bandwidth of 100MHz and 9060MHz, with a bandwidth of 50MHz. A downconverter electronics, built for tests at FLASH, converts the HOMs to an intermediate frequency of 70MHz. The MTCA (Micro Telecommunications Computing Architecture) standard will be used for the XFEL. Thus it is important to have a performance study of the downconverter test-electronics using the MTCA digitizer card SIS8300. In the digitizer the IF frequency of 70MHz is undersampled with a clock frequency of 108MS/s. The paper presents the performance of the digitizer together with the test-electronics. A comparison with a 216MS/s VME (Versa Module Eurocard) digitizer is made.