ICFA Mini Workshop on High Order Modes in Superconducting Cavities 2016

Session

Student Session

23 Aug 2016, 09:00

Konferenzsaal A (Warnemünde)

59. Eigenvalue Tracking for the Sensitivity Analysis of Higher Order Modes

Niklas Georg (TU Darmstadt)

23/08/2016, 09:00

The electromagnetic field distribution as well as the resonating frequency of various modes in cavities are very sensitive to small geometry deformations. We propose the application of Isogeometric Analysis (IGA) for the spatial discretization of the problem since IGA allows for the exact description of the domains and for a straightforward and convenient way of handling geometrical...

60. Cavity design study for the Higgs and Top running modes of the FCC-ee

Shahnam Gorgi Zadeh (Universitaet Rostock (DE))

23/08/2016, 09:30

In the design study of future circular collider (FCC) a lepton collider (FCC-ee) is foreseen as a potential intermediate step toward building a 100 TeV pp-collider (FCC-hh). The lepton collider shall operate at four different energies in order to study the properties of Z, W, H and top quark with unprecedented precision. Based on the preliminary studies, a single cavity design that can serve...

62. Wakefield Calculation in Dielectrically Lined Rectangular Waveguides Based on a Semi-Analytical Eigenmode Expansion

Franziska Reimann (University of Rostock)

23/08/2016, 10:00

Dielectrically lined waveguides are planned to be used as a passive wakefield dechirper for the electron beam at the ELBE facility of the Helmholtz-Zentrum Dresden Rossendorf. In this work we introduce the design of such a passive wakefield dechirper based on the analysis of dielectrically lined rectangular waveguides with a semi-analytical model developed at the University of Rostock. The...

65. HOM-based Cavity Alignment Measurement at FLASH

Thorsten Hellert (DESY)

23/08/2016, 13:30

TESLA-type accelerating cavities installed at FLASH and the European XFEL are equipped with two higher order mode (HOM) couplers damping these modes in order to prevent beam breakup instabilities. The dipole mode signals from the HOM couplers can be used for beam based cavity alignment measurements since their excitation is proportional to the offset and kick of the transferring beam with...

66. Pre-installation spectral response analysis of the HiLumi LHC crab cavity HOM couplers

Mitchell James Alexander (Lancaster University)

23/08/2016, 14:00

Part of the HiLumi LHC upgrade includes the use of superconducting Niobium crab cavities. The two proposed cavity designs are the Double Quarter Wave (DQW) and Radio Frequency Dipole (RFD). The DQW crab cavity will be tested in the Super Proton Synchrotron (SPS) at CERN in 2018. Both cavities require Higher Order Mode (HOM) couplers to prevent beam excited HOMs from perturbing the crabbing...

67. Higher Order Modes based Beam Phase Measurements at the European XFEL

liangliang shi (DESY)

23/08/2016, 14:30

The control of the RF phase and amplitude in accelerating cavities is vital for the operation of superconducting accelerators. The beam phase is normally inferred from the beam induced accelerating mode. On the contrary, the beam phase can also be obtained from beam induced higher order modes by comparing to the fundamental mode. We present results of beam phase measurements carried out at the...