2011 Particle Accelerator Conference - List of Authors (Zaplatin, E.N.)

Paper	Title	Page
TUP029	Low-Beta Superconducting RF Cavity Tune Options	865
	E.N. Zaplatin FZJ, Jülich, Germany
	The main method of the superconducting RF cavity frequency tuning is a resonator wall deformation. Since the highest frequency sensitivity on the geometry change is an accelerating gap variation, the "standard" place of deformation tuning force application in different cavity types are the cavity beam ports. A series of low-beta cavities (QWR, HWR, spoke-type) with different options of tuning have been investigated. Every option is compared with beam port displacement. The problem of resonator frequency shift self-compensation caused by external pressure fluctuations is discussed.

TUP031	Project X Elliptical Cavity Structural Analyses	868
	E.N. Zaplatin FZJ, Jülich, Germany
	Project X is proposed at Fermi National Accelerator Laboratory high-intensity proton accelerator complex that could provide beam for a variety of physics projects. Superconducting resonators will be used for beam acceleration. Here we report a structural design of elliptical cavities with resonance frequency 650 MHz and β=0.91 and 0.61. Since there is a concern that the pressure in the helium plumbing will not be stable when the cryomodules are connected to the liquid helium supply and helium gas returns it is necessary to provide the cavity stiffening with requirements of 15 Hz amplitude frequency shift. The cavity RF and mechanical properties are investigated. The calculations of the cavity frequency shift with pressure for different schemes of cavity stiffening were provided. The criterion for the optimization was the minimization of a resonant frequency dependence on an external pressure. Based on the results of these simulations several options on cavity stiffening have been proposed. Additionally, the cavity stiffening structural scheme for self-compensation of resonator detuning caused by external pressure fluctuation have been investigated.

Paper

Title

Page

Low-Beta Superconducting RF Cavity Tune Options

865

E.N. Zaplatin
FZJ, Jülich, Germany

The main method of the superconducting RF cavity frequency tuning is a resonator wall deformation. Since the highest frequency sensitivity on the geometry change is an accelerating gap variation, the "standard" place of deformation tuning force application in different cavity types are the cavity beam ports. A series of low-beta cavities (QWR, HWR, spoke-type) with different options of tuning have been investigated. Every option is compared with beam port displacement. The problem of resonator frequency shift self-compensation caused by external pressure fluctuations is discussed.

TUP031

Project X Elliptical Cavity Structural Analyses

868

E.N. Zaplatin
FZJ, Jülich, Germany

Project X is proposed at Fermi National Accelerator Laboratory high-intensity proton accelerator complex that could provide beam for a variety of physics projects. Superconducting resonators will be used for beam acceleration. Here we report a structural design of elliptical cavities with resonance frequency 650 MHz and β=0.91 and 0.61. Since there is a concern that the pressure in the helium plumbing will not be stable when the cryomodules are connected to the liquid helium supply and helium gas returns it is necessary to provide the cavity stiffening with requirements of 15 Hz amplitude frequency shift. The cavity RF and mechanical properties are investigated. The calculations of the cavity frequency shift with pressure for different schemes of cavity stiffening were provided. The criterion for the optimization was the minimization of a resonant frequency dependence on an external pressure. Based on the results of these simulations several options on cavity stiffening have been proposed. Additionally, the cavity stiffening structural scheme for self-compensation of resonator detuning caused by external pressure fluctuation have been investigated.