M. E. SCHULZE**, J. D. GILPATRICK, W. P. LYSENKO, L. J. RYBARCYK, J. D. SCHNEIDER, H. V. SMITH, JR, L. M. YOUNG
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] 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 dump. 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 rms spot size passes through a transverse waist. Measurements are presented for peak currents between 25 and 100 mA. Different approaches to analyzing the data are described.
[1] H.V. Smith, et al., 'Update On The Commissioning Of The Low-Energy Demonstration Accelerator (LEDA) Radio-Frequency Quadrupole (RFQ),' Proceeding 1999 ICFA Workshop on The Physics of High Brightness Beams, in press
* Work supported at LANL under contract to the US DOE
** General Atomics
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