Synchrotron radiation based beam diagnostics at the Fermilab Tevatron

TL;DR

This paper describes the adaptation of synchrotron radiation diagnostics for proton beams at Fermilab's Tevatron, enabling beam profiling and abort gap monitoring using visible light detection.

Contribution

It introduces two novel synchrotron radiation-based devices for beam profile and abort gap measurements in a proton accelerator, previously thought impractical.

Findings

Successful imaging of proton and antiproton beam profiles.

Effective measurement of abort gap beam intensity.

Comparison with existing profile systems validates the new diagnostics.

Abstract

Synchrotron radiation has been used for many years as a beam diagnostic at electron accelerators. It is not normally associated with proton accelerators as the intensity of the radiation is too weak to make detection practical. However, if one utilizes the radiation originating near the edge of a bending magnet, or from a short magnet, the rapidly changing magnetic field serves to enhance the wavelengths shorter than the cutoff wavelength, which for more recent high energy proton accelerators such as Fermilab's Tevatron, tends to be visible light. This paper discusses the implementation at the Tevatron of two devices. A transverse beam profile monitor images the synchrotron radiation coming from the proton and antiproton beams separately and provides profile data for each bunch. A second monitor measures the low-level intensity of beam in the abort gaps which poses a danger to both the accelerator's superconducting magnets and the silicon detectors of the high energy physics experiments. Comparisons of measurements from the profile monitor to measurements from the flying wire profile systems are presented as are a number of examples of the application of the profile and abort gap intensity measurements to the modelling of Tevatron beam dynamics.