The implementation and further improvements of superconducting undulators are part of the European XFEL facility development program. Within this program, a magnetic field test facility is being developed. Named SUNDAE2 (Superconducting UNDulAtor Experiment 2), it aims to perform in-vacuum magnetic field measurements of superconducting undulators (SCUs) with three techniques: Hall probe, moving wire, and pulsed wire. This contribution presents the updates and status of SUNDAE2.

Superconducting Undulators (SCUs) can produce higher photon flux and cover a wider photon energy range compared to permanent magnet undulators (PMUs) with the same vacuum gap and period length. To build the know-how to implement superconducting undulators for future upgrades of the European XFEL facility, the test stand SUNDAE1 for the characterization of SCU is being developed. The purpose of SUNDAE1 is the training, tuning and development of new SCU coils by means of precise magnetic field measurements. The experimental setup will allow the characterization of magnets up to 2m in length. These magnets will be immersed in a Helium bath at 4K or 2K temperature. In this article, we describe the experimental setup and highlight its expected performances.

The pulsed wire method is an attractive option to measure the magnetic field in insertion devices, mainly for those with restricted access (e.g., small gaps, in-vacuum/cryogenic environments, etc.). Besides first and second field integrals, experiments have proved the feasibility of reconstructing the magnetic field profile. Undulators with a small gap and short period are — and are planned to be — used at diffraction-limited storage rings and free-electron lasers. This contribution outlines the pulsed wire system’s requirements to perform magnetic field reconstruction in such undulators. We examine the main expected limitations, particularly the dispersive, finite pulse-width, discretization error, and sag effects. Furthermore, we present the current status of developing the pulsed wire system at the European XFEL.

We propose to develop, characterize and operate a superconducting undulator (SCU) afterburner consisting of 5 undulator modules (1 module = 2 SCU coils of 2 m length and 1 phase shifter) plus a pre-series prototype at the SASE2 hard X-ray beamline of European XFEL. This afterburner will produce an output in the order of 1010 ph/pulse at photon energies above 30 keV. The project is divided into the production of a pre-series prototype module and a small-series production of 5 modules. Central goals of this R&D activity are: the demonstration of the functionality of SCUs at an X-ray FEL, the set up of the needed infrastructure to characterize and operate SCUs, the industrialization of such undulators, and the reduction of the price per module. In this contribution, the main parameters and specifications of the pre-series prototype module are described.

Learning how to reconstruct the magnetic field profile from the pulsed wire method (PWM) is of fundamental importance to characterize undulators with limited magnetic gap accessibility. This paper presents a new data processing approach to reconstruct undulator magnetic field profiles from the PWM. We study via numerical simulations the accuracy and precision of the novel approach to recover the local undulator parameter and the root-mean-square (RMS) phase error. Due to the wire parameters uncertainties, the PWM can, in the best case, reach an accuracy of approximately 10−3 to reconstruct the local undulator parameter, and a precision (needed to determine the magnetic field quality) of about 10−5. Furthermore, our results show that the RMS phase error can be determined with a precision better than 0.2°. This contribution opens the possibility to apply the PWM to perform magnetic field reconstruction in small-gap short-period long undulators for advanced light sources.

At the European XFEL, we are designing a superconducting afterburner for the SASE2 hard X-ray beamline. It will consist of a series of five undulator modules plus a pre-series one called S-PRESSO. One module corresponds to two superconducting undulator (SCU) coils of 2m length plus one phase shifter. Such an afterburner will enable photon energies above 30 keV. We foresee to install superconducting (SC) phase shifters in each undulator module to keep the correct phase delay between the electron beam and photon beam. In this contribution, we present the required SC phase shifter parameters to enable operation in the electron beam energy range 11.5-17.5 GeV. We also analyze different magnetic designs satisfying the calculated specifications.

Desde 1997 o Brasil tem acesso a tecnologia de radiacao sincrotron com a inauguracao do Laboratorio Nacional de Luz Sincrotron (LNLS), localizado na cidade de Campinas, SP. Batizada de UVX, a fonte de luz sincrotron brasileira foi um marco no desenvolvimento cientifico e tecnologico do pais, permitindo pesquisas nas mais diversas areas do conhecimento, como nanotecnologia, biotecnologia, farmacos, agricultura, energias alternativas, dentre outros. Em 2009 o LNLS iniciou o projeto e a construcao de uma nova fonte de luz sincrotron brasileira. Nomeada Sirius, esta sendo desenvolvida para ser uma das mais avancadas do mundo na geracao de luz sincroton. O alto desempenho deste tipo de maquina depende fortemente da qualidade dos campos magneticos criados pelos inumeros magnetos que compoem a rede magnetica, o que exigem uma tecnica de caracterizacao rapida, acurada e precisa. O Grupo de Magnetos, responsavel pelo projeto, construcao e caracterizacao dos magnetos tanto da fonte UVX como da nova fonte, utiliza um sistema de medicao conhecido como Tecnica de Bobina Girante. Devido as especificacoes do projeto Sirius, foi necessario o aprimoramento da bancada de caracterizacao, objetivo este consolidado principalmente atraves da analise minuciosa das principais fontes de erro do sistema. Um modelo numerico desenvolvido para estudar algumas classes de erros da tecnica deu suporte para diversas correcoes na bancada, o que permitiu alcancar niveis de precisao comparaveis com os sistemas de caracterizacao de outros laboratorios. Paralelamente, foi construida a bancada de um sistema prototipo de medicao magnetico, nomeado Tecnica de Minibobina Girante, apresentando uma serie de vantagens em relacao as limitacoes da bancada oficial. Algumas das melhorias realizadas nesta bancada durante o seu desenvolvimento foram baseadas nos resultados advindos do modelo numerico das fontes de erros. Abstract