The electron cooler of the Antiproton Decelerator (AD) at CERN was initially developed for the Initial Cooling Experiment in 1979. It was subsequently adapted for use at LEAR and is currently employed in the AD. However, certain components of the cooler are now more than 40 years old and lack spare parts. To ensure the reliable operation of the AD, a new electron cooler is under development. This presentation focuses on the development of the new electron gun and collector that will provide the 2.4 A / 27 keV electron beam. The process involves choosing the gun/collector design, informed by electron-beam simulations, which aim to achieve the lowest transverse temperature of the electron beam within the cooling section and the highest collection efficiency of the collector. Subsequently, the gun and collector undergo meticulous testing and characterization on a dedicated test bench. The design undergoes iterative refinement to address issues related to high voltage sparks, vacuum pressure, and electron losses. Distinguishing features of the new cooler that make it more reliable compared to its predecessor will also be discussed.

In the final cooling stages for a muon collider, the transverse emittances are reduced while the longitudinal emittance is allowed to increase. In previous studies, Final 4-D cooling used absorbers within very high field solenoids to cool low-momentum muons. Simulations of the systems did not reach the desired cooling design goals. In this study, we develop and optimize a different conceptual design for the final 4D cooling channel, which is based on using dense wedge absorbers. We used G4Beamline to simulate the channel and Python to generate and analyze particle distributions. We optimized the design parameters of the cooling channel and produced conceptual designs (corresponding to possible starting points for the input beam) which achieve transverse cooling in both x and y by a factor of ~3.5. These channels achieve a lower transverse and longitudinal emittance than the best design previously published.

Coherent electron Cooling (CeC) experiment aims on demonstrating cooling if 26.5 GeV/u ion beam circulating in RHIC. We will present results of the CeC experiment with special focus won the use and the control of the broad-band micro-bunching Plasma Cascade Amplifier with bandwidth of 15 THz. We will also discuss connection of this experiment with the developing the CeC cooler for future