2010/09/09 by Gennady Romanov, Romanov, Gennady, V.S. Kashikhin +2
Engineering · #Particle accelerators and beam dynamics #Particle Accelerators and Free-Electron Lasers #Superconducting Materials and Applications
paper · pdf · doi:10.48550/arxiv.1009.1857
In order to produce muon beam of high enough quality to be used for a Muon\nCollider, its large phase space must be cooled several orders of magnitude.\nThis task can be accomplished by ionization cooling. Ionization cooling\nconsists of passing a high-emittance muon beam alternately through regions of\nlow Z material, such as liquid hydrogen, and very high accelerating RF cavities\nwithin a multi-Tesla solenoidal focusing channel. But first high power tests of\nRF cavity with beryllium windows in solenoidal magnetic field showed a dramatic\ndrop in accelerating gradient due to RF breakdowns. It has been concluded that\nexternal magnetic fields parallel to RF electric field significantly modifies\nthe performance of RF cavities. However, magnetic field in Helical Cooling\nChannel has a strong dipole component in addition to solenoidal one. The dipole\ncomponent essentially changes electron motion in a cavity compare to pure\nsolenoidal case, making dark current less focused at field emission sites. The\nsimulation of dark current dynamic in HCC performed with CST Studio Suit is\npresented in this paper.\n