Development of MUSES-ACR electron cooler

An electron cooler (EC) device for the Accumulator Cooler Ring (ACR) in the MUSES project is currently under development. The electron beam energy is varied from 30 keV to 250 keV with a maximum current of 4.1 A. An axial magnetic field of 0.2 T in a 3.6 m solenoid is chosen to satisfy the magnetization condition for the lightest ions and the expansion factor of 20 corresponds to the field of 4 T in the gun section. The details of the design and technological issues are discussed.