A5057797133- Advanced X-ray Imaging Techniques
- Particle Accelerators and Free-Electron Lasers
- Advanced Electron Microscopy Techniques and Applications
- Advanced Fiber Laser Technologies
- Semiconductor Lasers and Optical Devices
- Crystallography and Radiation Phenomena
- Photonic and Optical Devices
- Particle accelerators and beam dynamics
- Laser-Plasma Interactions and Diagnostics
- Medical Imaging Techniques and Applications
- Diamond and Carbon-based Materials Research
- Enzyme Structure and Function
- Advanced X-ray and CT Imaging
- Solid State Laser Technologies
- Gyrotron and Vacuum Electronics Research
- High-pressure geophysics and materials
- Optical Imaging and Spectroscopy Techniques
- Photoacoustic and Ultrasonic Imaging
- Semiconductor Quantum Structures and Devices
- Lanthanide and Transition Metal Complexes
- Chemical Reactions and Mechanisms
- Optical Systems and Laser Technology
- Environmental Chemistry and Analysis
- Superconducting Materials and Applications
- Advancements in Photolithography Techniques
SLAC National Accelerator Laboratory
2011-2025
State Key Laboratory of Pulsed Power Laser Technology
2024
Handan College
2023
Linac Coherent Light Source
2012-2021
State Key Laboratory on Integrated Optoelectronics
2017
Zhejiang University
2002-2017
State Key Laboratory of Modern Optical Instruments
2017
JDSU (United States)
2013-2015
Changchun University of Science and Technology
2013-2014
Stanford University
2011-2013
Charge density wave (CDW) correlations have recently been shown to universally exist in cuprate superconductors. However, their nature at high fields inferred from nuclear magnetic resonance is distinct that measured by x-ray scattering zero and low fields. Here we combine a pulsed magnet with an free electron laser characterize the CDW YBa2Cu3O6.67 via up 28 Tesla. While zero-field order, which develops below T ~ 150 K, essentially two-dimensional, lower temperature beyond 15 Tesla, another...
Structural rearrangements within single molecules occur on ultrafast time scales. Many aspects of molecular dynamics, such as the energy flow through excited states, have been studied using spectroscopic techniques, yet goal to watch evolve their geometrical structure in real remains challenging. By mapping nuclear motions femtosecond x-ray pulses, we created real-space representations evolving dynamics during a well-known chemical reaction and show series time-sorted structural snapshots...
The Linac Coherent Light Source has added a self-seeding capability to the soft x-ray range using grating monochromator system. We report demonstration of with measured resolving power 2000--5000, wavelength stability ${10}^{\ensuremath{-}4}$, and an increase in peak brightness by factor 2--5 across photon energy 500--1000 eV. By avoiding need for at experimental station, self-seeded beam can deliver as much 50-fold higher users.
Measurements of the spatial and temporal coherence single, femtosecond x-ray pulses generated by first hard free-electron laser, Linac Coherent Light Source, are presented. Single-shot measurements were performed at 780 eV photon energy using apertures containing double pinholes in "diffract-and-destroy" mode. We determined a length 17 μm vertical direction, which is approximately size focused Source beam same direction. The analysis diffraction patterns produced with largest separation...
A simple method for generating single-spike hard x-ray pulses in free-electron lasers (FELs) has been developed at the Linac Coherent Light Source (LCLS). This is realized by nonlinear bunch compression using 20-pC charge, demonstrated regime 5.6 and 9 keV, respectively. Measurements show about half of FEL shots containing a spectrum. At 5.6-keV photon energy, have mean pulse energy 10 μJ with 70% intensity fluctuation full width maximum evaluated to be 200-as level.Received 12 May...
A scheme for generating two simultaneous hard-x-ray free-electron laser pulses with a controllable difference in photon energy is described and then demonstrated using the self-seeding setup at Linac Coherent Light Source (LCLS). The takes advantage of existing LCLS equipment, which allows independent rotations diamond crystal. degrees freedom are used to select nearby crystal reflections, causing wavelengths be present forward transmitted seeding x-ray pulse. system must support...
We experimentally and theoretically study the coincidence count rate for down-converted x-ray photons. Because of photoionization, parametric down-conversion at wavelengths generally involves loss theoretical description requires a Langevin approach. By working in transmission geometry (Laue) rather than Bragg previous experiments, we obtain an improvement signal-to-noise ratio 12.5, find agreement between experiment theory.
We show that the spectral properties of a self-amplified spontaneous emission x-ray free-electron laser can be controlled by modulating gain in magnetic undulators, thus producing one or several lines within single few femtosecond pulse. By varying field along undulator and electron beam transport line, system we demonstrate tailor spectrum to optimally meet numerous experimental requirements for multicolor operation.
This paper reports novel measurements of x-ray optical radiation on an absolute scale from the intense and ultra-short generated in soft regime a free electron laser.We give brief description detection principle for which was specifically adapted this photon energy range.We present data characterizing instrument at Linac Coherent Light Source (LCLS) with respect to radiant power output transmission by using detector temporarily placed downstream end instrument.This provides estimation...
We present a novel method for measuring the duration of femtosecond x-ray pulses from self-amplified spontaneous emission free electron lasers by performing statistical analysis in spectral domain. Analytical expressions correlation function were derived linear regime to extract both pulse and spectrometer resolution. Numerical simulations confirmed that can be also used nonlinear regime. The was demonstrated experimentally at Linac Coherent Light Source durations down 13 fs FWHM.
We have developed an on-line spectrometer for hard x-ray free-electron laser (XFEL) radiation based on a nanostructured diamond diffraction grating and bent crystal analyzer.Our method provides high spectral resolution, interferes negligibly with the XFEL beam, can withstand intense pulses at repetition rates of >100 Hz.The is capable providing shot-to-shot information normalization data obtained in scientific experiments optimization accelerator operation parameters.We demonstrated these...
A double-crystal diamond (111) monochromator recently implemented at the Linac Coherent Light Source (LCLS) enables splitting of primary X-ray beam into a pink (transmitted) and monochromatic (reflected) branch. The first crystal, with thickness ∼100 µm, provides sufficient transmittance to enable simultaneous operation two beamlines. This article reports design, fabrication characterization second (300 µm-thick) crystals utilized in optical assemblies holding these crystals. Each crystal...
Abstract Ultrafast light pulses can modify electronic properties of quantum materials by perturbing the underlying, intertwined degrees freedom. In particular, iron-based superconductors exhibit a strong coupling among nematic fluctuations, spins and lattice, serving as playground for ultrafast manipulation. Here we use time-resolved X-ray scattering to measure lattice dynamics photoexcited BaFe 2 As . On optical excitation, no signature an change crystal symmetry is observed, but oscillates...
We demonstrate a thermally tuned SGDBR laser integrated with semiconductor optical amplifier and spectral filter achieving 70kHz linewidth, 50dB SMSR, +17dBm fiber- coupled output power over 41nm wavelength range across the C-band.
We demonstrate a thermally tuned SGDBR laser with high thermal tuning efficiency; 300kHz spectral linewidth, +16dBm fiber-coupled output power, 40dB SMSR, and millisecond timescale are achieved over 40nm wavelength range across the C-band.
Multiplexing of the Linac Coherent Light Source beam was demonstrated for hard X-rays by spectral division using a near-perfect diamond thin-crystal monochromator operating in Bragg geometry. The wavefront and coherence properties both reflected transmitted beams were well preserved, thus allowing simultaneous measurements at two separate instruments. In this report, structure determination prototypical protein performed serial femtosecond crystallography simultaneously with time-resolved...
This paper presents a novel method to improve the longitudinal coherence, efficiency and maximum photon energy of x-ray free electron lasers (XFELs). The is equivalent having two separate concatenated XFELs. first uses one bunch electrons reach saturation regime, generating high power self-amplified spontaneous emission pulse at fundamental third harmonic. filtered through an attenuator/monochromator seeds different in second FEL, using and/or harmonic as input signal. In our we combine...
The ePix100 x-ray camera is a new system designed and built at SLAC for experiments the Linac Coherent Light Source (LCLS). first member of family detectors around single hardware software platform, supporting variety front-end chips. With readout speed 120 Hz, matching LCLS repetition rate, noise lower than 80 e-rms pixels 50 µm × µm, this offers viable alternative to fast readout, direct conversion, scientific CCDs in imaging mode. detector, applications such as X-ray Photon Correlation...
X-ray free-electron lasers (XFELs) provide extremely bright and highly spatially coherent x-ray radiation with femtosecond pulse duration. Currently, they are widely used in biology material science. Knowledge of the XFEL statistical properties during an experiment may be vitally important for accurate interpretation results. Here, first time, we demonstrate Hanbury Brown Twiss (HBT) interferometry performed diffraction mode at source. It allowed us to determine directly from Bragg peaks...
We describe the design and operation of a transmissive single-shot spectrometer for measurement hard x-ray free electron laser (FEL) source spectrum at Linac Coherent Light Source (LCLS). The was built around 10 μm thick near-perfect silicon single crystal that cylindrically bent. Its energy range covered full FEL bandwidth while its resolution sufficient resolving spectral spikes characteristics FELs. application will not only greatly facilitate understanding optimization sources, but can...
A new hybrid pixel array detector, the ePix100, has been developed at SLAC for tender and hard x-ray experiments Linac Coherent Light Source (LCLS). It is intended low noise good spatial resolution applications, particularly X-ray Photon Correlation Spectroscopy (XPCS) in combination with wavelength dispersive spectrometers. The detector 50 μm size less than 100 e- r.m.s. over range of tested operating conditions. series measurements to validate its performance x-rays was carried out...