MCP Based Detectors Installation in European XFEL

An important task of the photon beam diagnostics at the European XFEL is providing reliable tools for measurements aiming at the search for and fine tuning of the FEL creating SASE process. Radiation detectors based on micro channel plates (MCP) will be use at the European XFEL. Detectors operate in a wide dynamic range from the level of spontaneous emission to the saturation level (between a few nJ and 25 mJ), and in a wide wavelength range from 0.05 nm to 0.4 nm for SASE1 and SASE2, and from 0.4 nm to 4.43 nm for SASE3. Photon pulse energies are measured by MCP with anode and with photodiode. The photon beam image is measured by MCP imager with phosphor screen anode. Three MCP devices will be installed, one after each SASE undulator of the European XFEL (SASE1, SASE2, and SASE3). At present time MCP SASE1 and MCP SASE3 were installed in XFEL tunnel. Calibration and acceptance test experiments with MCP detectors and their electronic is under discussion

Experience with MCP-based Photon Detector at FLASH2

We present recent experimental results on statistical measurements of amplification process in FLASH2 SASE FEL. Micro-channel plate (MCP) detector is used for precise measurements of the radiation pulse energy. DAQ based software is used for cross-correlation of the SASE FEL performance and electron beam jitters. Analysis of machine jitters essential for SASE FEL operation has been performed. Application of gating strategy with measured machine parameters allows us to isolate machine jitters from fundamental SASE fluctuations. Subsequent application of statistical techniques for characterization of SASE FEL radiation allows to derive such important quantities as gain length, saturation length, radiation pulse duration, coherence time, and degree of transverse coherence

Radiation detectors based on microchannel plates for free-electron lasers

Detectors based on microchannel plates are used to detect the radiation of free-electron lasers operating in short-wavelength ranges. We present descriptions of radiation detectors for the FLASH free-electron laser (DESY, Hamburg) that operates in vacuum ultraviolet and soft X-ray wavelength ranges (4–100 nm) and detectors for the European X-ray free electron laser that is being constructed in Hamburg and is designed to operate in the X-ray wavelength range from 0.05 to 4.3 nm

Synchrotron Radiation Test Validations of European XFEL MCP-based Detectors at DORIS Beamline BW1

Radiation detectors based on micro channel plates (MCP) are planned for installation at the European XFEL. Main purpose of these detectors is searching a signature of lasing and further fine tuning of the FEL process. Detectors operate in a wide dynamic range from the level of spontaneous emission to the saturation level (between a few nJ and 25 mJ), and in a wide wavelength range from 0.05 nm to 0.4 nm for SASE1 and SASE2, and from 0.4 nm to 4.43 nm for SASE3. Photon pulse energies are measured with traditional MCP with anode and with photodiode. The photon beam image is measured by MCP imager with phosphor screen anode. The SR tests validation of the MCP-based detector applied for XFEL SASE1 and SASE2 were performed at the DORIS beamline BW1 and photon energy of 8.5-12.4 keV. The absolute measurem ents of a photon pulse energy of 0.03 nJ and larger for hard X-ray radiation were performed with application of MCP and photodiode detectors. Pulse-to-pulse photon energy measurements with MCPs and a JINR silicon photo detector were done with 192 ns and 96 ns repetition intervals. The SR beam imaging measurement at X-ray irradiation was performed at test validation experiments

Synchrotron Radiation Test Validations of European XFEL MCP-based Detectors at DORIS Beamline BW1

Radiation detectors based onμchannel plates (MCP) are planned for installation at the European XFEL. Main purpose of these detectors is searching a signature of lasing and further fine tuning of the FEL process. Detectors operate in a wide dynamic range from the level of spontaneous emission to the saturation level (between a few nJ and 25 mJ), and in a wide wavelength range from 0.05 nm to 0.4 nm for SASE1 and SASE2, and from 0.4 nm to 4.43 nm for SASE3. The SR tests validation of the MCP-based detector applied for XFEL lines SASE1 and SASE2 were performed at the DORIS beamline BW1 at SR with photon energy of 8.5-12.4 keV. The absolute measurements of a photon pulse energy for hard X-ray radiation were performed with application of MCP and photodiode detectors. Pulse-to-pulse photon energy measurements with MCPs and silicon photo detector were done with 192 ns and 96 ns repetition intervals. The SR beam imaging measurement at X-ray irradiation was performed at test validation experiments

Radiation detectors based on microchannel plates for free-electron lasers

Detectors based on microchannel plates are used to detect the radiation of free-electron lasers operating in short-wavelength ranges. We present descriptions of radiation detectors for the FLASH free-electron laser (DESY, Hamburg) that operates in vacuum ultraviolet and soft X-ray wavelength ranges (4–100 nm) and detectors for the European X-ray free electron laser that is being constructed in Hamburg and is designed to operate in the X-ray wavelength range from 0.05 to 4.3 nm

Development of experimental techniques for the characterization of ultrashort photon pulses of extreme ultraviolet free-electron lasers

One of the most challenging tasks for extreme ultraviolet, soft and hard x-ray free-electron laser photon diagnostics is the precise determination of the photon pulse duration, which is typically in the sub 100 fs range. Nine different methods, able to determine such ultrashort photon pulse durations, were compared experimentally at FLASH, the self-amplified spontaneous emission free-electron laser at DESY in Hamburg, in order to identify advantages and disadvantages of different methods. Radiation pulses at a wavelength of 13.5 and 24.0 nm together with the corresponding electron bunch duration were measured by indirect methods like analyzing spectral correlations, statistical fluctuations, and energy modulations of the electron bunch and also by direct methods like autocorrelation techniques, terahertz streaking, or reflectivity changes of solid state samples. In this paper, we present a comprehensive overview of the various techniques and a comparison of the individual experimental results. The information gained is of utmost importance for the future development of reliable pulse duration monitors indispensable for successful experiments with ultrashort extreme ultraviolet pulses

Simultaneous operation of two soft x-ray free-electron lasers driven by one linear accelerator

Extreme-ultraviolet to x-ray free-electron lasers (FELs) in operation for scientific applications are up to now single-user facilities. While most FELs generate around 100 photon pulses per second, FLASH at DESY can deliver almost two orders of magnitude more pulses in this time span due to its superconducting accelerator technology. This makes the facility a prime candidate to realize the next step in FELs—dividing the electron pulse trains into several FEL lines and delivering photon pulses to several users at the same time. Hence, FLASH has been extended with a second undulator line and self-amplified spontaneous emission (SASE) is demonstrated in both FELs simultaneously. FLASH can now deliverMHzpulse trains to two user experiments in parallel with individually selected photon beam characteristics. First results of the capabilities of this extension are shown with emphasis on independent variation of wavelength, repetition rate, and photon pulse length

A MHz-repetition-rate hard X-ray free-electron laser driven by a superconducting linear accelerator

International audienceThe European XFEL is a hard X-ray free-electron laser (FEL) based on a high-electron-energy superconducting linear accelerator. The superconducting technology allows for the acceleration of many electron bunches within one radio-frequency pulse of the accelerating voltage and, in turn, for the generation of a large number of hard X-ray pulses. We report on the performance of the European XFEL accelerator with up to 5,000 electron bunches per second and demonstrating a full energy of 17.5 GeV. Feedback mechanisms enable stabilization of the electron beam delivery at the FEL undulator in space and time. The measured FEL gain curve at 9.3 keV is in good agreement with predictions for saturated FEL radiation. Hard X-ray lasing was achieved between 7 keV and 14 keV with pulse energies of up to 2.0 mJ. Using the high repetition rate, an FEL beam with 6 W average power was created