The Origination and Diagnostics of Uncaptured Beam in the Tevatron and Its Control by Electron Lenses

TL;DR

This paper investigates the causes and diagnostics of uncaptured beam in the Tevatron, and demonstrates how electron lenses effectively control this beam to prevent magnet quenching during high-energy operations.

Contribution

It introduces a new diagnostics system for measuring uncaptured beam parameters and details the successful application of electron lenses for beam control in the Tevatron.

Findings

Diagnostics system effectively measures uncaptured beam parameters

Electron lenses successfully remove uncaptured beam

Uncaptured beam control prevents magnet quenching

Abstract

In the Collider Run II, the Tevatron operates with 36 high intensity bunches of 980 GeV protons and antiprotons. Particles not captured by the Tevatron RF system pose a threat to quench the superconducting magnet during acceleration or at beam abort. We describe the main mechanisms for the origination of this uncaptured beam, and present measurements of its main parameters by means of a newly developed diagnostics system. The Tevatron Electron Lens is effectively used in the Collider Run II operation to remove uncaptured beam and keep its intensity in the abort gaps at a safe level.