A GdBCO bulk staggered array undulator

Abstract

The Insertion Device group of the Paul Scherrer Institute has started an R&D program on a high temperature superconducting undulator to reduce the period length and increase the undulator's magnetic field well beyond the present capability. Simulation results for a 10 mm period and 4 mm magnetic gap staggered array of GdBCO bulks predict peak magnetic field above 2 T. Building on the existing working principle of undulator design and simulated performance, the first experimental results of a 5 period 6.0 mm gap short undulator measured in the new test facility available at the University of Cambridge will be presented together with details of the experimental setup and sample preparation.

Fully-staggered-array bulk Re-Ba-Cu-O short-period undulator: large-scale 3D electromagnetic modelling and design optimization using A-V and H-formulation methods

“…A five-period Gd-Ba-Cu-O bulk undulator with a period length of 10 mm and magnetic gap of 6 mm was tested at the University of Cambridge [4]. As a first attempt to verify the BHTSU concept, FC magnetization experiments were conducted with a conservative background solenoid field of 6 T, rather than the simulated 10 T. Figure 9 shows the calculated undulator field B y along the z-axis of the central period of the 3D BHTSU model (10 mm period length, 6 mm magnetic gap) after FC magnetization from 6 T. The results are compared with the simulation results from a 2D periodical undulator model and the measurement results from the central period of the Gd-Ba-Cu-O bulk undulator prototype [4,52], and there is excellent agreement between all of these. There is a small difference for the 3D model (around z = −2.5 mm) and for the 2D model (around z = 2.5 mm).…”

“…As described in [2,4], a sinusoidal undulator field B y along the electron beam axis (z-axis) can be generated in staggeredarray superconducting bulks after FC magnetization with a superconducting solenoid. In the models, we approximate this by applying a uniform background magnetizing field.…”

“…In the models, we approximate this by applying a uniform background magnetizing field. The past prototypes and FEM simulations were all based on staggered-array half-moon-shaped bulk superconductors acting as a compact insertion device [3,4,81,82]. In this section, we study the undulator field generated by staggered-array cuboid bulks, to which the pre-stress can be applied more homogeneously because of their regular shape.…”

“…Figure 9.Comparison between the measured undulator field Bytaken from the central period of the Gd-Ba-Cu-O bulk undulator prototype -after FC magnetization from 6 T at 10 K[4], the simulation results in 2D[52] and the simulation results in 3D obtained by using the A-V formulation-based backward computation method.…”

Magnetization Current Simulation of High-Temperature Bulk Superconductors Using the ANSYS Iterative Algorithm Method

“…Research and development work on implementing self-developed numerical methods into the finite-element method (FEM) software ANSYS is ongoing at the Paul Scherrer Institute (PSI) for the purpose of modelling and optimizing the short-period and high-field staggered-array high-temperature superconductor (HTS) bulk undulators which are highly appreciated for the construction of compact free electron lasers (FELs) [1]- [3]. The idea of developing ANSYS comes from its powerful capability for mechanical or multiphysics-coupled simulations and its parametric design language (APDL) which allows the secondary development or the user-defined element [4].…”