- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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The Percival 2-Megapixel monolithic active pixel imager
摘要： The peak brilliance reached by today’s Free-Electron Laser and Synchrotron light sources requires photon detectors matching their output intensity and other characteristics in order to fully realize the sources’ potential. The Pixellated Energy Resolving CMOS Imager, Versatile And Large (Percival) is a dedicated soft X-ray imager (0.25–1 keV) developed for this purpose by a collaboration of DESY, Rutherford Appleton Laboratory/STFC, Elettra Sincrotrone Trieste, Diamond Light Source, and Pohang Accelerator Laboratory. Following several generations of prototypes, the Percival “P2M” 2-Megapixel imager — a 4.5×5 cm monolithic, stitched sensor with an uninterrupted imaging area of 4×4 cm2 (1408×1484 pixels of 27×27 μm — was produced and has demonstrated basic functionality with a ?rst-light image using visible light. It is currently being brought to full operation in a front-illuminated con?guration. The readout system being commissioned in parallel has been developed speci?cally for this imager which will produce — at full 300 Hz frame rate — data at 20 Gbit/s. A ?rst wafer with eight Percival P2M chips has undergone backthinning to enable soft X-ray detection. It has been diced and chips are currently being wirebonded. We summarize here the P2M system, the project status, and show the P2M sensor’s ?rst response to visible light.
关键词： X-ray detectors,Instrumentation for FEL
更新于2025-09-23 15:23:52
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Laguerre-Gaussian Mode Laser Heater for Microbunching Instability Suppression in Free-Electron Lasers
摘要： Microbunching instability (MBI) driven by beam collective effects is known to be detrimental to high-brightness storage rings, linacs, and free-electron lasers (FELs). One known way to suppress this instability is to induce a small amount of energy spread to an electron beam by a laser heater. The distribution of the induced energy spread greatly affects MBI suppression and can be controlled by shaping the transverse profile of the heater laser. Here, we present the first experimental demonstration of effective MBI suppression using a LG01 transverse laser mode and compare the improved results with respect to traditional Gaussian transverse laser mode at the Linac Coherent Light Source. The effects on MBI suppression are characterized by multiple downstream measurements, including longitudinal phase space analysis and coherent radiation spectroscopy. We also discuss the role of LG01 shaping in soft x-ray self-seeded FEL emission, one of the most advanced operation modes of a FEL for which controlled suppression of MBI is critical.
关键词： Free-electron lasers,Microbunching instability,LG01 mode,Laser heater,Soft x-ray self-seeded FEL,Gaussian mode,MBI suppression
更新于2025-09-23 15:21:01
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Operation and performance of the JUNGFRAU photon detector during first FEL and synchrotron experiments
摘要： JUNGFRAU is a hybrid pixel photon detector developed at the Paul Scherrer Institut for free electron laser (FEL) and synchrotron applications. A charge integrating detector, JUNGFRAU features three automatically switching gains per pixel which adjust the amplification factor to the amount of deposited charge. This enables single photon sensitivity, while ensuring a dynamic range over four orders of magnitude. Each detector module consists of eight 256 × 256 pixel ASICs bump-bonded to a single 320 μm thick silicon sensor, resulting in half a million pixels of 75 μm pitch arranged in 1024 × 512 arrays for a sensitive area of approximately 8 × 4 cm2. Modules can be combined in various configurations to produce larger systems. These proceedings present the required steps, both operational and in terms of data processing, necessary to perform experiments with the JUNGFRAU detector. This includes the calculation and application of pedestal and gain corrections and the geometric arrangement of the recorded image. Examples of these techniques in action will be presented from the first experiments performed with JUNGFRAU detectors; the pilot experiment of the SwissFEL Bernina beamline and proof-of-principle macromolecular crystallography measurements from the X06SA beamline of the Swiss Light Source. Successful operation and data processing methods from FEL and synchrotron facilities will be compared and contrasted, and experience of overcoming challenges in the two scenarios will be shared. Finally, the capability of JUNGFRAU for FEL and synchrotron applications will be demonstrated.
关键词： Instrumentation for synchrotron radiation accelerators,X-ray detectors,Instrumentation for FEL
更新于2025-09-23 15:21:01
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[IEEE 2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz2018) - Nagoya, Japan (2018.9.9-2018.9.14)] 2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Lasing and saturation of CAEP THz FEL facility
摘要： A high power THz free electron laser (FEL) facility is under construction at China Academy of Engineering Physics (CAEP) since October, 2011. The radiation frequency of the FEL facility is designed in range of 1~3 THz and the average output power is about 10 W. First lasing of the CAEP THz FEL (CTFEL) facility was obtained in August 29, 2017. Then the saturation operation is observed in September 20, 2017. The radiation frequency is sequentially as 1.99THz, 2.41THz and 2.92THz. And the average output power is larger than 10 W; the largest output power is about 20W. The peak power of micro-pulse is larger than 0.5MW. The optical resonator of CTFEL is optimized to ensure wavelength tunable in a wide range and high power operation. In this paper, the main designed and present status of the facility is given.
关键词： free electron laser,lasing,CAEP,saturation,FEL,THz
更新于2025-09-23 15:21:01
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Extremely high-intensity operation of a THz free-electron laser using an electron beam with a higher bunch charge
摘要： A higher intensity THz beam is generated with a free-electron laser (FEL) based on the L-band (1.3 GHz) electron linac at Osaka University by increasing the electron bunch charge four times higher from 1 nC in the conventional mode (the 108 MHz mode) to 4 nC in the new mode (the 27 MHz mode). This is realized by expanding the electron bunch intervals four times longer with the grid pulser of the electron gun, generating a series of 5 ns pulses at a repetition frequency of 27 MHz (the 48th subharmonic of 1.3 GHz), whereas the beam loading of the linac remains unchanged. The energy of an FEL macropulse comprised of many micropulses is measured in the 27 MHz mode to be approximately 28.5 mJ at a maximum of around 65 μm or 4.6 THz compared with the maximum macropulse energy of 13 mJ in the 108 MHz mode. The maximum micropulse energy in the 27 MHz mode is approximately 260 μJ using 110 micropulses, which is estimated by a macropulse duration of 4 μs and micropulse intervals of 36.9 ns. The micropulse energy is nearly 10 times higher than the micropulse energies in the conventional mode and in other FELs in the same wavelength or frequency region.
关键词： Free-electron laser (FEL),Terahertz (THz),Electron beam,High charge
更新于2025-09-23 15:19:57
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HgCdTe Detector Saturation Using Infrared Free Electron Laser and Infrared Synchrotron Radiation
摘要： Recently, the high-brilliance infrared synchrotron radiation source out of various infrared sources has become popular, and it is widely used in many fields of studies. For spectroscopy, the mercury cadmium telluride (MCT) detector is often used. It covers a wide mid-infrared region and has high sensitivity, but saturates easily. In this work, the detector saturation behavior was investigated in detail using infrared synchrotron radiation and infrared free electron laser. We found that the saturation and its elimination show various patterns depending on the amplifier gain, light intensity and the time structure of the light. The influence of the saturation to the spectral shape is also discussed.
关键词： Saturation,Infrared Synchrotron Radiation,Infrared FEL,MCT Detector
更新于2025-09-19 17:13:59
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Degradation of Human Serum Albumin by Infrared Free Electron Laser Enhanced by Inclusion of a Salen-Type Schiff Base Zn (II) Complex
摘要： A salen‐type Schiff base Zn(II) complex included in human serum albumin (HSA) protein was examined by UV‐Vis, circular dichroism (CD), and fluorescence (PL) spectra. The formation of the composite material was also estimated by a GOLD program of ligand–protein docking simulation. A composite cast film of HSA and Zn(II) complex was prepared, and the effects of the docking of the metal complex on the degradation of protein molecules by mid‐infrared free electron laser (IR‐FEL) were investigated. The optimum wavelengths of IR‐FEL irradiation to be used were based on experimental FT‐IR spectra and vibrational analysis. Using TD‐DFT results with 6‐31G(d,p) and B3LYP, the IR spectrum of Zn(II) complex could be reasonably assigned. The respective wavelengths were 1652 cm?1 (HSA amide I), 1537 cm?1 (HSA amide II), and 1622 cm?1 (Zn(II) complex C=N). Degradation of HSA based on FT‐IR microscope (IRM) analysis and protein secondary structure analysis program (IR‐SSE) revealed that the composite material was degraded more than pure HSA or Zn(II) complex; the inclusion of Zn(II) complex enhanced destabilization of folding of HSA.
关键词： IR‐FEL,TD‐DFT,human serum albumin,Schiff base,fluorescence,Zn(II) complex
更新于2025-09-19 17:13:59
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Formation of a Nanoscale Graphite Hydrosol under the Influence of Terahertz Laser Radiation
摘要： The present report describes a new phenomenon, namely the formation of a nanoscale hydrosol during short-term exposure of the surface of water by focused terahertz radiation of the Novosibirsk free-electron laser. The composition of the particles is completely determined by the material of the container used. Hydrosols are technologically convenient forms for scientific and industrial applications, which are characterized by uniform deposition and high catalytic activity used in medicine, optics, and as a suspension for sample preparation for chemical and elemental analysis. This article presents the results of our study of graphite particles formed in water, a suspension, which is in demand for industrial purposes. Commercially available high purity graphite (99.5%) of GE grade is used. The initial material and the resulting particles are studied using an atomic force and electron microscope with an elemental analyzer.
关键词： terahertz radiation,Novosibirsk FEL,nanoparticles,graphite,hydrosol
更新于2025-09-16 10:30:52
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Editorial: Lasers in Accelerator Science and Secondary Emission Light Source Technology
摘要： Unifying laser and accelerator physics holds great promise for the development of future particle accelerators, light sources, and other scienti?c instruments due to increasingly synergistic advances at the cross section between these two ?elds. Their combined action has recently ushered in advanced accelerator facilities around the world that have enabled unique scienti?c and technological breakthroughs: from advanced electron and ion sources for high-energy physics to the ultrabright x-ray pulses to study ultrafast phenomena at elemental spatio-temporal scales [1–4]. The progress of ultra-intense femtosecond lasers, now attaining multi PetaWatt peak power, has recently enabled the demonstration of GeV electron beams in centimeter scale plasma accelerating section [5, 6], with the recent world record reaching 8 GeV in 20 cm [7]. As for ultrafast x-ray science, in their relatively short time since their advent, x-ray free electron lasers [8, 9] (FEL) have demonstrated the capacity to answer grand fundamental questions in a diverse set of areas in physics, chemistry, and biology, such as revealing vibration coherence in molecules [10], molecular bond formation, charge migration, and dissociation dynamics [11, 12], or ultrafast isomerization in biomolecules [13, 14], among many others. Further advances in facilities—such as augmented brightness, attosecond duration, or seeded emission—are poised to creating new scienti?c frontiers in atomic-scale correlated systems and ultrahigh resolution inner shell spectroscopies.
关键词： free electron laser (FEL),ultrafast optics,X-ray emission,non-linear optics,laser accelerated particles,secondary emission and photoemission
更新于2025-09-16 10:30:52
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Minimum Spectral Bandwidth in Echo Seeded Free Electron Lasers
摘要： This paper examines the impact of non-linear longitudinal phase distortions on the spectral bandwidth in echo seeded free electron lasers (FELs). It extends the existing theory developed in Hemsing [1] for echo-enabled harmonic generation (EEHG) to include finite laser pulse durations. An analytic expression for the shape of the optimized longitudinal bunching envelope is derived, and is used to determine the laser and electron beam pulse durations that minimize the seeded bandwidth in the presence of arbitrary phase distortions. The time-bandwidth product (TBP) is also derived, and is shown that the TBP and the bandwidth increase by no more than √2 from their transform-limited values when the bandwidth is minimized.
关键词： FEL (free electron laser),chirp,xray,seeded,nonlinear,EEHG,harmonic,echo
更新于2025-09-16 10:30:52