Beam dynamics in the spallation neutron source linac

Author

Jeon, D.

Author_Institution

SNS Project, Oak Ridge Nat. Lab., TN, USA

Volume

1

fYear

2003

fDate

12-16 May 2003

Firstpage

107

Abstract

Being an 1.44MW machine, the beam loss requirement on the SNS linac is less than 1 W/m and controlling halo particle generation is of great importance. Beam dynamics aspects of the SNS linac design are presented considering various halo generation mechanisms. A halo generation mechanism in the non-periodic lattices such as the SNS linac MEBT (Medium-Energy Beam-Transport between RFQ and DTL) is reported. We find that the nonlinear space charge force resulting from large transverse beam eccentricity ∼2:1 in the ∼1.6-m-long MEBT chopper section is responsible for halo formation. The proposed mitigation measures are modifying the MEBT optics and introducing adjustable collimators in the MEBT. The transient beam behavior of the LEBT and MEBT choppers is also studied for the fate of partially chopped beams.

Keywords

linear accelerators; neutron sources; particle beam diagnostics; proton accelerators; 1.44 MW; 1.44MW machine; 1.6 m; MEBT optics; adjustable collimators; beam dynamics; beam loss requirement; halo particle generation; large transverse beam eccentricity; nonlinear space charge force; nonperiodic lattices; spallation neutron source linac; Acceleration; Boring; Choppers; Lattices; Linear particle accelerator; Neutrons; Nonlinear optics; Particle beams; Resonance; Space charge;

fLanguage

English

Publisher

ieee

Conference_Titel

Particle Accelerator Conference, 2003. PAC 2003. Proceedings of the

ISSN

1063-3928

Print_ISBN

0-7803-7738-9

Type

conf

DOI

10.1109/PAC.2003.1288853

Filename

1288853