13 research outputs found
MCP Based Detectors Installation in European XFEL
No full textAn 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
Synchrotron Radiation Test Validations of European XFEL MCP-based Detectors at DORIS Beamline BW1
No full textRadiation 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
Measurements of Ultrasmall Charges with MCP Detector in FLASH Accelerator
No full textStructure of the dark current passed through the undulator is a matter of great concern. Two effects can contribute to the dark current: emission of electrons from "hot" spots in the gun, and generation of "ghost" bunches due to possible leakage of the photoinjector laser. MCP based photon detector has been used for measurements of radiation energy from electron bunch. For small radiation densities the light is detected by direct illumination of the MCP plate, and for large densities a small angle scattering scheme is realized when metallic mesh scatters tiny fraction of light on the MCP plate. In the present experiment we used geometry of direct illumination of MCP plate aiming detection of "ghost" bunches which may generate parasitically from the laser driven electron gun. Reduction of background conditions allowed us to detect light produced by electron bunches with extremely small charges, on a sub-femtocoulomb values. We measured for the first time structure of the dark current passing through the FLASH undulator. We have also been able to measure a high contrast of radiation produced by the photoinjector laser pulses switched on and off by a 1 MHz repetition rate Pockels cells
MCP-Based Detectors: Calibration and First Photon Radiation Measurements
No full textDetectors based on microchannel plates (MCPs) are used to detect radiation from free-electron lasers. Three MCP detectors have been developed by JINR for the European XFEL (SASE1, SASE2 and SASE3 lines). These detectors are designed to operate in a wide dynamic range from the level of spontaneous emission to the SASE saturation level (between a few nJ up to 25 mJ), 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 detectors measure photon pulse energies with an anode and a photodiode. The photon beam image is observed with an MCP imager with a phosphor screen. At present, the SASE1 and SASE3 MCP detectors are commissioned with XFEL beams. Calibration and first measurements of photon radiation in multibunch mode are performed with the SASE1 and SASE3 MCPs. The MCP detector for SASE2 and its electronics are installed in the XFEL tunnel, technically commissioned, and are now ready for acceptance tests with the X-ray beam
Integrating an AI Chatbot to Improve the Eugene Career Exploration Platform
No full textAbstract Background Many psychology students face underemployment, despite having employable skills; however, this underemployment can be reduced by teaching undergraduate students the job-ready skills they earn in their bachelor\u27s degree (Burning Glass Institute, 2024). The research team implemented a website named Eugene, a tool that shows career options for psychology majors tailored by knowledge, skills, and abilities (KSAs) they earn in their courses. The 2025 student assessment of Eugene indicated that 63% of respondents would use Eugene when considering post-graduation plans; however, when asked about the limitations of Eugene, over 40% responded that both the structure and instructions could be improved (Eugene Assessment Report, 2025). To implement these improvements, this proposal focuses on integrating a chatbot assistant into Eugene to assist students in their future careers. Methods The project will use Microsoft Copilot to create a chatbot that gives students access to immediate feedback and clarification throughout the Eugene process. The team will feed KSAs into the AI chatbot, then test and score the response. If the score satisfies the team’s grading criteria, the process will continue to the next phase. If not, the team will go back to feeding it relevant knowledge. Then, the team will create a survey for students to rate the effectiveness and utility of the chatbot. Evaluation will also incorporate IP tracking to quantify website usage. Evaluation will be focused on students\u27 perception of usability, efficiency, helpfulness, and satisfaction of Eugene to psychology undergraduate students. Results from the 2025 Eugene assessment will be compared to the new assessment to be sent out in spring 2026. Expected Outcomes & Implications Integrating a chatbot assistant into Eugene is expected to improve usability and efficiency by helping undergraduate students better interpret Eugene’s instructions and output. We anticipate increased engagement, reflected in site analytics and survey responses, as students find the platform more responsive and tailored to their needs. Enhanced clarity given by the chatbot is likely to shift student perceptions, making Eugene a more trusted tool for career planning. If successful, the chatbot will become a permanent feature, strengthening Eugene’s role in bridging psychology undergraduates to meaningful employment. This initiative aligns with increasing student perception by assisting undergraduate students’ inquiries about KSAs and competencies, demonstrating how targeted technological enhancements can elevate student outcomes and increase job searchability
Experience with MCP-based Photon Detector at FLASH2
No full textWe 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
SASE Gain-Curve Measurements with MCP-Based Detectors at the European XFEL
No full textRadiation detectors based on microchannel plates (MCP) are used for characterization of the Free-Electron Laser (FEL) radiation and measurements of the Self-amplified spontaneous emission (SASE) gain curve at the European XFEL. Photon pulse energies are measured by the MCPs with an anode and by a photodiode. There is one MCP-based detector unit installed in each of the three photon beamlines downstream of the SASE1, SASE2, and SASE3 undulators. MCP detectors operate in a wide dynamic range of pulse energies, from the level of spontaneous emission up to FEL saturation. Their wavelength operation range overlaps with the whole range of radiation wavelengths of SASE1 and SASE2 (from 0.05 nm to 0.4 nm), and SASE3 (from 0.4 nm to 5 nm). In this paper we present results of SASE gain-curve measurements by the MCP-based detectors
Photoinduced Low Spin to High Spin Transition in a [2x2] Fe(II) Metallogrid: Diode Laser-Pumped Photocrystallography at the P11 Beamline in PETRA III, DESY
No full textWe report on the photoinduced spin crossover (SCO) transition from a 2HS-2LS to a 3HS-1LS state in a [2x2] Fe(II) metallogrid complex using molecular crystals with static photocrystallography at a first ever attempt in the beamline P11 of the PETRA III synchrotron, DESY. A class 3B diode laser was used to induce the transition under controlled irradiation conditions. Structural characterization was achieved through single-crystal X-ray diffraction (SCXRD) measurements post-irradiation, revealing significant changes in average Fe-N distances, consistent with SCO behavior. Our experimental setup enables precise alignment necessary for photo-excitation using a class 3B diode laser along with a compact focusing optics. The longest dimension of the combined setup of the diode head and the focusing optics is not more than 32cm. The setup showcasing the utility of a compact diode laser system which can even be conveniently used in synchrotron-based pump-probe photocrystallography experiments for a wide range of molecular crystals
Radiation detectors based on microchannel plates for free-electron lasers
No full textDetectors 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
Author Correction: A MHz-repetition-rate hard X-ray free-electron laser driven by a superconducting linear accelerator
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