Beam-halo measurements in high-current proton beams
C K Allen1, K C D Chan, P L Colestock
1Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA.
Physical Review Letters
|November 22, 2002
Summary
This study investigated proton beam halo formation in a quadrupole channel. Experimental results support theoretical models predicting emittance growth and halo amplitude.
Area of Science:
- Physics
- Particle Accelerators
- Beam Dynamics
Background:
- Beam halo is a critical issue in high-current particle beams, affecting accelerator performance and stability.
- Understanding halo formation mechanisms is essential for designing advanced particle accelerators.
Purpose of the Study:
- To experimentally investigate the formation and evolution of beam halo in a high-current proton beam.
- To compare experimental data with predictions from theoretical models of halo formation.
Main Methods:
- A 6.7-MeV proton beam was propagated through a 52-quadrupole periodic-focusing channel.
- Quadrupole gradients were adjusted to match or mismatch the injected beam conditions.
- Emittances and beamwidths were measured using profile data.
Main Results:
- Experimental measurements of emittance growth and beamwidth were obtained.
- Results were compared against predictions from a free-energy model for emittance growth.
- Results were also compared against predictions from a particle-core model for halo amplitude.
Conclusions:
- Experimental findings support the free-energy model's predictions for maximum emittance growth.
- Experimental findings support the particle-core model's predictions for maximum halo amplitude.
- The study validates the current theoretical understanding of beam halo formation in periodic focusing channels.
