CLASSE, Ithaca, New York
Minimization of power of higher order modes (HOMs) in a multicell cavity was done using derivatives of the parameter defining losses with respect to geometric parameters of the cavity cells. For the Cornell Energy Recovery Linac most dangerous are dipole modes causing beam break-up (BBU). As a start point of optimization the shape with minimal losses at the fundamental mode was taken. Further changing the shape for better propagation of HOMs was done with degradation of the fundamental mode loss parameter within 1 %. Substantial improvement of the BBU parameter was achieved.
CLASSE, Ithaca, New York
Comparison of cell shapes for a multicell cavity can be made in terms of (1) the aperture radius for a given wave length, (2) the peak electric field normalized to acceleration field, and (3) the wall slope angle. All other important figures of merit, when this choice is done, become a matter of optimization. Several geometries of cells of superconducting cavities are compared from this standpoint.
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
CLASSE, Ithaca, New York
FZD, Dresden
STFC/DL, Daresbury, Warrington, Cheshire
LBNL, Berkeley, California
Stanford University, Stanford, Califormia
TRIUMF, Vancouver
Cornell University, Ithaca, New York
DESY, Hamburg
The collaborative development of an optimised cavity/cryomodule solution for application on ERL facilities has now progressed to final assembly and testing of the cavity string components and their subsequent cryomodule integration. This paper outlines the testing and verification processes for the various cryomodule sub-components and details the methodology utilised for final cavity string integration. The paper also highlights the modifications required to integrate this new cryomodule into the existing ALICE cryo-plant facility at Daresbury Laboratory.