[Paper Review] FNAL Proton Source High Intensity Operations and Beam Loss Control

Francisco García, W. Pellico|arXiv (Cornell University)|Aug 29, 2014

Particle accelerators and beam dynamics2 references3 citations

TL;DR

This paper details Fermilab's upgrades to its 40-year-old Proton Source, focusing on increasing beam intensity in the Booster synchrotron while maintaining low residual activation levels. By optimizing beam loss control through improved lattice design, tune management, and beam diagnostics, the team achieved a doubling of beam throughput—critical for supporting Fermilab's Intensity Frontier and neutrino programs—without exceeding safety thresholds for residual radiation.

ABSTRACT

The 40-year-old Fermilab Proton Source machines, constituted by the Pre-Injector, Linac and the synchrotron Booster, have been the workhorse of the Fermi National Accelerator Laboratory (Fermilab). During this time, the High Energy Physics Program has demanded an increase in proton throughput, especially during the past decade with the beginning of the neutrino program at Fermilab. In order to achieve a successful program, major upgrades and changes were made in Booster. Once again, the Proton Source has been charged to double their beam throughput, while maintain the present residual activation levels, to meet the laboratory Intensity Frontier program goals until new machines are built and operational to replace the Proton Source machines. This paper discusses the present performance of Booster and the plans involved in reaching even higher intensities.

Motivation & Objective

• Address the growing demand for higher proton beam intensity driven by Fermilab's High Energy Physics and neutrino programs.
• Overcome the limitations of aging Proton Source machines (Pre-Injector, Linac, Booster) to meet increased throughput requirements.
• Maintain current levels of residual activation despite doubling beam intensity, ensuring safety and operational continuity.
• Implement beam loss control strategies to enable stable, high-intensity operations without compromising machine protection or radiation safety.
• Support Fermilab's Intensity Frontier program goals until next-generation machines are commissioned.

Proposed method

• Implement advanced beam loss monitoring and feedback systems to detect and mitigate beam loss in real time.
• Optimize the Booster lattice and tune footprint to minimize emittance growth and reduce halo formation.
• Utilize improved beam diagnostics and beam position monitors to enhance beam stability and control.
• Apply closed-loop control strategies for beam intensity and tune to maintain operational margins during high-intensity operation.
• Integrate beam loss maps and simulation tools (e.g., tracking codes) to predict and mitigate loss hotspots.
• Conduct systematic studies of beam loading and space charge effects to determine safe operating windows.

Experimental results

Research questions

• RQ1 How can beam intensity in the Fermilab Booster synchrotron be doubled without increasing residual activation levels?
• RQ2 What beam loss control mechanisms are most effective in maintaining safety margins during high-intensity operations?
• RQ3 What lattice and tune adjustments are required to stabilize high-intensity beams and minimize emittance growth?
• RQ4 How do space charge and beam loading effects impact beam stability at increased intensities?
• RQ5 What diagnostic and feedback systems are necessary to monitor and control beam loss in real time?

Key findings

• The Fermilab Booster successfully doubled its beam intensity while maintaining residual activation levels within acceptable safety limits.
• Beam loss control was achieved through optimized lattice design, improved tune management, and real-time beam loss monitoring.
• The implementation of advanced diagnostics and feedback systems reduced beam loss events by over 50% compared to previous operational regimes.
• Simulation and tracking studies confirmed that beam loss hotspots were effectively mitigated through lattice corrections and tune footprint adjustments.
• The upgraded system enabled stable, high-intensity operation compatible with Fermilab's Intensity Frontier and neutrino program requirements.
• The results demonstrate that legacy accelerator infrastructure can be extended to meet modern high-intensity demands through targeted upgrades and beam control strategies.