Multipactor suppression in dielectric-assist accelerating structures via diamondlike carbon coatings

Multipactor discharges are widely observed in the accelerator field, and their suppression has been studied to improve performance. A dielectric-assist accelerating (DAA) cavity is a standing-wave that attains Q-value of over 100,000 at room temperature by using reflection dielectric layer; DAA expected be used with small RF power source high-duty operation. Thus far, maximum field cavities limited few MV/m multipactor. By applying diamond-like carbon (DLC) coating reduce secondary electron emission coefficient without sacrificing cavity, we have demonstrated $6~[{\rm \mu s}]$ pulse can injected into more than 10~[MV/m] while suppressing