JLab, Newport News, Virginia, USA
In this report, we present the development of a fast harmonic kicker, a normal conducting deflecting cavity that kicks electron bunches from ERL ring to circulator cooler ring (CCR) in Jefferson Lab Electron Ion Collider (JLEIC). This cavity utilizes 5 harmonic modes to generate a sharp kick to the electron bunch at high frequency of 86.6MHz, which is injection frequency into the CCR. The beam dynamics study and RF design of the hardware was reported in [1],[2]. In this report we present further progress including impedance by higher order mode (HOM) study and mechanical design for fabrication.
[1] G. Park, et. al TUPAL068, Proc. of IPAC 2018, Apr 2018, Vancouver, BC Canada
[2] G. Park, et. al, Proc. of IPAC2019, May 2019, Melbourne, Australia
THCOXBS01
JLab, Newport News, Virginia, USA
HZB, Berlin, Germany
Waveguide HOM dampers are widely used in high current RF cavities, as waveguides are natural high pass RF filters and can easily handle high RF power. In this presentation, the author will review a few typical waveguide HOM load designs, especially the recently developed high power HOM loads for BERLinPro and BESSY-VSR. We will report the RF-thermal-mechanical design, fabrication technology, absorber material choice, as well as the testing results of these HOM loads.
THCOZBS03
JLab, Newport News, Virginia, USA
ODU, Norfolk, Virginia, USA
Bunched-beam electron cooling is a key feature of all proposed designs of the future electron-ion collider, and a requirement for achieving the specified collision luminosity of the order 1034 cm-2s−1. For the Jefferson Lab Electron Ion Collider (JLEIC), fast cooling of ion beams will be accomplished via so-called ’magnetized electron cooling’, where the cooling process will occur inside a long solenoid field, which will be part of the collider ring and facilitated using a circulator ring and Energy Recovery Linac (ERL). In this contribution, we describe recent achievements that include the generation of picosecond-bunch magnetized beams at average currents up to 28 mA with exceptionally long photocathode lifetime, and independent demonstrations of magnetized beam with high bunch charge up to 700 pC at 10s of kHz repetition rates using a compact 300 kV DC high voltage photogun with an inverted insulator geometry and alkali-antimonide photocathodes. Magnetization characterization including beam rotation and drift emittance were also presented for various gun bias voltages and laser spot sizes at the photocathode using 532 nm lasers with DC and RF time structure. These accomplishments mark important steps toward demonstrating the feasibility of a technically challenging JLEIC cooler design using magnetized beams.