Speaker
Description
Ionization cooling is critical for a muon collider aiming to achieve high-luminosity collisions. In the cooling channel, the reference lab-frame relativistic β is between 0.88 and 0.93, a regime in which space charge effects cannot be ignored. The beam waist also varies substantially along the cooling lattice, suggesting that space charge effects may change significantly throughout the channel. In this work, we use electromagnetic fields resolved with a commercial particle-in-cell code and an in-house post-processing method to compute the wakefields of a rigid muon beam with transverse waist determined by the design lattice. We show that the space charge contribution to the composite wake can become significant when the beam transverse size is strongly compressed in later stages of the cooling channel. In parallel, we assess the effects of realistic solenoid fields combined with accelerating cavity-mode fields on field-emitted dark currents, building on previous models developed to explain the increased probability of RF breakdown in magnetic fields. Using RF-Track, we simulate beamlet dynamics and evaluate how these combined fields influence particle transport and impact behavior. The results reveal changes in collision statistics and provide a more detailed picture of beam and dark-current dynamics under realistic cooling-channel field configurations.
| Working group | WG4 |
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