Status and Commissioning of the European XFEL Beam Loss Monitor System

The European XFEL MTCA based Beam Loss Monitor(BLM) system is composed of about 450 monitors, whichare part of the Machine Protection System (MPS). The BLMs detect losses of the electron beam, in order to protect accelerator components from damage and excessive activation, in particular the undulators, since they are made of permanent magnets. Also each cold accelerating module is equipped with a BLM to measure the sudden onset offield emission (dark current) in cavities. In addition some BLMs are used as detectors for wire- scanners.Experience from the already running BLM system in FLASH2 which is based on the same technology, led to a fast implementation of the system in the XFEL. Further firmware and server developments related to alarm generation and handling are ongoing.The BLM systems structure, the current status and the different possibilities to trigger alarms which stop the electron beam will be presented

A Fast Wire Scanner System for the European XFEL

The European-XFEL is an X-ray Free Electron Laser facility located in Hamburg (Germany). The 17.5 GeV superconducting accelerator will provide photons simultaneously to several user stations. Currently 14 Wire Scanner stations are used to image transverse beam profiles in the high energy sections. These scanners provide a slow scan mode for beam halo studies and beam optics matching. When operating with long bunch trains (>100 bunches) fast scans will be used to measure beam sizes in an almost non-destructive manner. This paper briefly describes the wire scanner setup and focusses on the fast scan concept and first measurements

Performance of a Downconverter Test-electronics with MTCA-based Digitizers for Beam Position Monitoring in 3.9 GHz Accelerating Cavities

Beam-excited higher order modes (HOM) in 3.9GHz accelerating cavities are planned to be used for beam position monitoring at the European XFEL. The selected HOMs are located around 5440MHz, with a bandwidth of 100MHz and 9060MHz, with a bandwidth of 50MHz. A downconverter electronics, built for tests at FLASH, converts the HOMs to an intermediate frequency of 70MHz. The MTCA (Micro Telecommunications Computing Architecture) standard will be used for the XFEL. Thus it is important to have a performance study of the downconverter test-electronics using the MTCA digitizer card SIS8300. In the digitizer the IF frequency of 70MHz is undersampled with a clock frequency of 108MS/s. The paper presents the performance of the digitizer together with the test-electronics. A comparison with a 216MS/s VME (Versa Module Eurocard) digitizer is made.Comment: International Beam Instrumentation Conference, IBIC2012, Tsukuba, Japan, Oct 1-4, 201

HOM Based Beam Diagnostics Study at FLASH

HOM based beam diagnostics study at FLAS

Upgrade and Status of Standard Diagnostic-Systems at FLASH and FLASHForward

Electron beam diagnostics plays a crucial role in the precise and reliable generation of ultra-short high brilliance XUV and soft X-ray beams at the Free ElectronLaser in Hamburg (FLASH). Most diagnostic systems monitor each of up to typically 600 bunches per beam,with a frequency of up to 1 MHz, a typical charge between 0.1 and 1 nC and an energy of 350 to 1250 MeV.The diagnostic monitors have recently undergone a major upgrade. This process started several years ago with the development of monitors fulfilling the requirements of the European XFEL and of the FLASH2 undulator beamline and it continued with their installation and commissioning. Later they have been further improved and an upgrade was made in the old part of the linac. Also the FLASHForward plasma-wakefield acceleration experiment has been installed in the third beamline.This paper will give an overview of the upgrade of the BPM, Toroid and BLM systems, pointing out to their improved performance. Other systems underwent a partial upgrade, mainly by having their VME-based ADCs replaced with MTCA type. The overall status of the diagnostic will be reviewed

Multi-Beamline Operation at the European XFEL

The European XFEL uses a unique beam distribution scheme to direct electron bunches to its three undulator lines.The accelerator delivers up to 600 microsecond long bunchtrains, out of which parts or individual bunches can be selectedfor photon production in any of the FELs. This contribution gives a brief overview of the kicker-septum scheme facilitating this and highlights how even complex bunch patterns can easily be configured via the timing system

The Status of the SASE3 Variable Polarization Project at the European XFEL

The undulator systems at the European XFEL consist of two hard X ray systems, SASE1 and SASE2, and one soft X ray system, SASE3. All three systems are equipped with planar undulators using permanent neodymium magnets. These systems allow the generation of linearly polarized radiation in the horizontal plane. In order to generate variable polarization radiation in the soft X ray range, an afterburner is currently being implemented behind the SASE3 planar undulator system. It consists of four APPLE X helical undulators. The project, called SASE 3 Variable Polarization, is close to being put into operation. All four helical undulators have been installed in the tunnel during the 2021 2022 winter shutdown. This paper describes the status of the project and the steps toward its commissioning. It also presents lessons learned during the implementation of the projec