Instrument Control for Beam Position Monitor Calibration
and Diagnostics Using MATLAB

By Samuel Fanfan

This paper presents a project done in collaboration with Brookhaven National Laboratory for the application of Radio Frequency Beam Position Monitors (RF BPM). These Radio Frequency Beam Position Monitors are to be utilized in the National Synchrotron Light Source II particle accelerator facility post construction. The purpose of the RF BPM is to detect transverse beam position with sub-micron resolution and stability under normal operating conditions. In order to accurately measure the beam’s position it is crucial for the BPM’s four input channel receivers to be matched properly. Traditional calibration schemes comprise of manually adjusting a signal generator coupled to the RF BPM unit under test and recording the receiver signal strength for various power level settings. A MATLAB “RF BPM CalTool” has been developed to automate the process.

The tool interfaces with the instruments by means of Instrument Control and was developed utilizing the MathWorks Instrument Control Toolbox. Remote control of the signal generator is executed using the VISA-TCP protocol in conjunction with SCPI commands. Information exchange with the BPM is established using the ModBus-TCP protocol and the raw data is read and handled by the CalTool. A graphical user interface implements the aforementioned functionality along with a post-processing step. Testing of the tool was executed via simulation and trial-and-error exercises.

Full report (pdf)

Poster (pdf)