MOIBCC004
BNL, Upton, Long Island, New York, USA
The ability to produce high average current reliably and reproducibly over a long period of time with good quantum efficiency at visible wavelength is important for all ERL applications. There has been considerable interest in developing suitable cathodes for 24/7 operation under such stringent conditions. Recently, at BNL, we have fabricated cathodes with QE in the range of 10% for Cs-K-Sb cathodes and 5% for Na-K-Sb cathodes when irradiated with 532 nm laser and a single pulse charge up to 5 nC in the SRF gun has been produced. In this presentation, we discuss the fabrication of Cs-K-Sb and Na-K-Sb cathodes using both dispensers and effusion cells as sources of alkali metal, characterization of these cathodes, transporting them from the fabrication location to the RHIC tunnel under UHV conditions and installation in the electron guns in the tunnel.
BNL, Upton, Long Island, New York, USA
Non-magnetized bunched electron cooling of ion beams during low energy RHIC operation requires electron beam energy in the range of 1.6-2.6 MeV, with an average current up to 45 mA, very small energy spread, and low emittance. A 400 kV DC gun equipped with a photocathode and laser system will provide a source of high-quality electron beams. During DC gun test critical elements of LEReC such as laser beam system, cathode exchange system, cathode QE lifetime, DC gun stability, beam instrumentation, the high-power beam dump system, machine protection system and controls has been tested under near- operational conditions [1]. We present the status, experimental results and experience learned during the LEReC DC gun beam testing.
[1] D. Kayran et al., DC Photogun Gun Test for RHIC Low Energy Electron Cooler (LEReC), NAPAC2016 proceedings, WEPOB54.
WEIDCC002
BNL, Upton, Long Island, New York, USA
Stony Brook University, Stony Brook, USA
SUNY SB, Stony Brook, New York, USA
SBU, Stony Brook, New York, USA
We are commissioning the accelerator for the Coherent Electron Cooling Proof-of-principle (CeC PoP) Experiment. The 113 MHz superconducting RF gun with Cs2KSb photocathode serves as a source of the electrons. The gun is designed to operate up to 5 nC beam with repetition rate of 78 kHz. In the paper we present status of the gun as well as achieved beam parameters. The photocathode performance (quantum efficieny, lifetime) is also discussed.