The Low-Energy Demonstration Accelerator (LEDA) radio-frequency quadrupole (RFQ) is a 100% duty factor (CW) linac that delivers >100 mA of H+ beam at 6.7 MeV. The 8-m-long, 350-MHz RFQ structure accelerates a dc, 75-keV, 110-mA H+ beam from the LEDA injector with >90% transmission. LEDA [1,2] consists of a 75-keV proton injector, 6.7-MeV, 350-MHz CW RFQ with associated high-power and low-level rf systems, a short high-energy beam transport (HEBT) and high-power (670-kW CW) beam stop. The beam emittance is inferred from wire scanner measurements of the beam profile at a single location in the HEBT. The beam profile is measured as a function of the magnetic field gradient in one of the HEBT quadrupoles. As the gradient is changed the spot size passes through a transverse waist. Measurements are presented for peak currents between 25 and 100 mA.
@article{arxiv.physics/0008071,
title = {Beam Emittance Measurements for the Low-Energy Demonstration Accelerator Radio-Frequency Quadrupole},
author = {M. E. Schulze and J. D. Gilpatrick and W. P. Lysenko and L. J. Rybarcyk and J. D. Schneider and H. V. Smith, and L. M. You},
journal= {arXiv preprint arXiv:physics/0008071},
year = {2012}
}