Superconducting undulator activities at the European X-ray Free-Electron Laser Facility

For more than 5 years, superconducting undulators (SCUs) have been successfully delivering X-rays in storage rings. The European X-Ray Free-Electron Laser Facility (XFEL) plans to demonstrate the operation of SCUs in X-ray free-electron lasers (FELs). For the same geometry, SCUs can reach a higher peak field on the axis with respect to all other available technologies, offering a larger photon energy tunability range. The application of short-period SCUs in a high electron beam energy FEL > 11 GeV will enable lasing at very hard X-rays > 40 keV. The large tunability range of SCUs will allow covering the complete photon energy range of the soft X-ray experiments at the European XFEL without changing electron beam energy, as currently needed with the installed permanent magnet undulators. For a possible continuous-wave (CW) upgrade under discussion at the European XFEL with a lower electron beam energy of approximately 7–8 GeV, SCUs can provide the same photon energy range as available at present with the permanent magnet undulators and electron energies. This paper will describe the potential of SCUs for X-ray FELs. In particular, it will focus on the different activities ongoing at the European XFEL and in collaboration with DESY to allow the implementation of SCUs in the European XFEL in the upcoming years

Arrays of Annular Antennas With SINIS Bolometers

For improving the dynamic range and sensitivity at high power load, we have integrated superconductor-insulator-normal metal-insulator-superconductor (SINIS) bolometers with a frequency selective surface (FSS)-based distributed absorber formed by a series and parallel array consisting of 25 annular antenna elements, each containing two SINIS bolometers. By using a design with 50 bolometers, we reduce incident power load on each bolometer, increase sensitivity and saturation power which is important for ground-based and balloon-borne telescopes with high background power loads. Our main detector pixel is optimized for a frequency band centered at 345GHz. The detectors are matched to incoming telescope beam by a back-to-back horn with a back reflector. Such a configuration improves both the efficiency and the bandwidth of the receiver. Measured voltage responsivity approaches 210(9) VW with an amplifier-limited voltage noise of 20nVHz(12), which corresponds to a NEP 10(-17) WHz(12). The linear voltage response for incoming power is observed for absorbed power of about 5 pW. The current responsivity for parallel array is 210(4) AW and the shot noise limited intrinsic noise equivalent power is NEP 510(-18)WHz(12). The noise equivalent temperature difference is NETD 100 KHz(12) at 2.7-K background radiation temperature

Status of the Undulator Systems for the European X-ray Free Electron Laser

The three undulator systems for the European XFEL consist of a total of 91Undulator Cells. Each cell consists of an Undulator Segment and an intersection. They will be operational by end of 2015. The serial production of the 91 Undulator Segments is a great challenge and without precedence. It is now in full swing. This contribution gives an overview over the most important design aspects as well as the experience and strategy with the serial production. Representative results of magnetic performance are given. The status of the other system components is briefly described

Microwave Receiving System Based on Cryogenic Sensors for the Optical Big Telescope Alt-Azimuth.

This article presents the results of evaluating the possibility of conducting radio astronomy studies in the windows of atmospheric transparency ~100, ~230, and ~350 GHz using the optical Big Telescope Alt-Azimuthal (BTA) of the Special Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS). A list of some promising astronomical tasks is proposed. The astroclimat conditions at the BTA site and possible optical, cryogenic, and mechanical interfaces for mounting a superconducting radio receiver at the focus of the optical telescope are considered. As a receiving system, arrays of detectors cooled to ~0.3 K based on the superconductor-insulator-normal metal-insulator-superconductor (SINIS) structure are proposed. The implementation of the project will make it possible to use the BTA site of the SAO RAS not only to solve some astronomical problems (it is possible to consider the implementation of a single observatory, the VLBI (very-long-baseline interferometry) mode in the Suffa, EHT (Event Horizon Telescope), and Millimetron projects), but it will also be used to test various cryogenic detectors in a real observatory

SASE3 Variable Polarization Project at the European XFEL

At the European XFEL, two undulator systems for hard and one for soft X-rays have been successfully put into operation. The SASE3 soft X-ray undulator system generates linearly polarized radiation in the horizontal plane. One of the requirements for extending the radiation characteristics is the ability to obtain different polarization modes. These include both right and left circular, elliptical polarization, or linear polarization at an arbitrary angle. For this purpose, a system consisting of four APPLE X helical undulators developed at the Paul Scherrer Institute (PSI) is used. This paper presents the design parameters of the SASE3 undulator system after modifying it with the helical afterburner. It also describes the methods and the design solutions different from those used at PSI. The status and schedule of the project are introduced

The Large Scale European XFEL Control System: Overview and Status of the Commissioning

The European XFEL is a 3.4 km long X-ray Free Electron Laser in the final construction and commissioning phase in Hamburg. It will produce 27000 bunches per second at 17.5 GeV. Early 2015 a first electron beam was produced in the RF-photo-injector and the commissioning of consecutive sections will follow during this and next year. The huge number and variety of devices for the accelerator, beam line, experiment, cryogenic and facility systems pose a challenging control task. Multiple systems, including industrial solutions, must be interfaced to each other. The large number of bunches requires a tight time synchronization (down to picoseconds) and high performance data acquisition systems. Fast feedbacks from front-ends, the DAQs and online analysis system with a seamless integration of controls are essential for the accelerator and the initially 6 experimental end stations. It turns out that the European XFEL will be the first installation exceeding 2500 FPGA components in the MicroTCA form factor and will run one of the largest PROFIBUS networks. Many subsystem prototypes are already successfully in operation. An overview and status of the XFEL control system will begiven

The Large Scale European XFEL Control System: Overview and Status of the Commissioning

The European XFEL is a 3.4km long X-ray Free Electron Laser in the final construction and commissioning phase in Hamburg. It will produce 27000 bunches per second at 17.5GeV. Early 2015 a first electron beam was produced in the RF-photo-injector and the commissioning of consecutive sections is following during this and next year. The huge number and variety of devices for the accelerator, beam line, experiment, cryogenic and facility systems pose a challenging control task. Multiple systems, including industrial solutions, must be interfaced to each other. The high number of bunches requires a tight time synchronization (down to picoseconds) and high performance data acquisition systems. Fast feedbacks from front-ends, the DAQs and online analysis system with a seamless integration of controls are essential for the accelerator and the initially 6 experimental end stations. It turns out that the European XFEL will be the first installation exceeding 2500 FPGA components in the MicroTCA form factor and will run one of the largest PROFIBUS networks. Many subsystem prototypes are already successfully in operation. An overview and status of the XFEL control system will be given

The Large Scale European XFEL Control System: Overview and Status of the Commissioning

The European XFEL is a 3.4 km long X-ray Free Electron Laser in the final construction and commissioning phase in Hamburg. It will produce 27000 bunches per second at 17.5 GeV. Early 2015 a first electron beam was produced in the RF-photo-injector and the commissioning of consecutive sections will follow during this and next year. The huge number and variety of devices for the accelerator, beam line, experiment,cryogenic and facility systems pose a challenging control task. Multiple systems, including industrial solutions, must be interfaced to each other. The large number of bunches requires a tight time synchronization (down to picoseconds) and high performance data acquisitionsystems. Fast feedbacks from front-ends, the DAQs and online analysis system with a seamless integration of controls are essential for the accelerator and the initially 6 experimental end stations. It turns out that the European XFEL will be the first installation exceeding 2500 FPGAcomponents in the MicroTCA form factor and will run one of the largest PROFIBUS networks. Many subsystem prototypes are already successfully in operation. An overview and status of the XFEL control system will be given