A5026407559- Gyrotron and Vacuum Electronics Research
- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Terahertz technology and applications
- Advanced X-ray Imaging Techniques
- Photonic and Optical Devices
- Superconducting and THz Device Technology
- Particle Detector Development and Performance
- Microwave Engineering and Waveguides
- Superconducting Materials and Applications
- Laser-Plasma Interactions and Diagnostics
- Advanced NMR Techniques and Applications
- Pulsed Power Technology Applications
- Advanced Electron Microscopy Techniques and Applications
- Photonic Crystals and Applications
- Laser-Matter Interactions and Applications
- Electron and X-Ray Spectroscopy Techniques
- Particle physics theoretical and experimental studies
- Radiation Therapy and Dosimetry
- Solid-state spectroscopy and crystallography
- Integrated Circuits and Semiconductor Failure Analysis
- Atomic and Subatomic Physics Research
- Crystallography and Radiation Phenomena
- Mechanical and Optical Resonators
- Laser Design and Applications
SLAC National Accelerator Laboratory
2015-2024
Stanford University
2016-2024
Menlo School
2017-2024
Space Science Institute
2023
Virginia Tech
2023
Brookhaven National Laboratory
2022
Stony Brook University
2022
Fermi National Accelerator Laboratory
2016-2022
Lawrence Berkeley National Laboratory
2022
University of California, Irvine
2022
The cost, size and availability of electron accelerators is dominated by the achievable accelerating gradient. Conventional high-brightness radio-frequency (RF) structures operate with 30-50 MeV/m gradients. Electron driven optical or infrared sources have demonstrated gradients orders magnitude above that conventional RF structures. However, laser-driven wakefield require intense femtosecond direct suffer from low bunch charge, sub-micron tolerances sub-femtosecond timing requirements due...
Dynamic nuclear polarization (DNP) increases the sensitivity of magnetic resonance (NMR) spectroscopy by using high frequency microwaves to transfer electrons spins. The enhancement in NMR can amount a factor well above 100, enabling faster data acquisition and greatly improved measurements. With increasing fields (up 23 T) used research, required for DNP falls into THz band (140-600 GHz). Gyrotrons have been developed meet demanding specifications NMR, including power levels tens watts;...
A design for a compact x-ray light source (CXLS) with flux and brilliance orders of magnitude beyond existing laboratory scale sources is presented. The based on inverse Compton scattering high brightness electron bunch picosecond laser pulse. accelerator novel high-efficiency standing-wave linac rf photoinjector powered by single ultrastable transmitter at X-band frequency. efficiency permits operation repetition rates up to 1 kHz, which further boosted 100 kHz operating trains bunches pC...
We report the experimental demonstration of a gyrotron traveling-wave-tube amplifier at 250 GHz that uses photonic band gap (PBG) interaction circuit. The achieved peak small signal gain 38 dB and 45 W output power 247.7 with an instantaneous $\ensuremath{-}3\text{ }\text{ }\mathrm{dB}$ bandwidth 0.4 GHz. can be tuned for operation from 245--256 widest 4.5 centered 253.25 was observed 24 dB. PBG circuit provides stability oscillations by supporting propagation transverse electric (TE) modes...
X-ray crystallography is one of the main methods to determine atomic-resolution 3D images whole spectrum molecules ranging from small inorganic clusters large protein complexes consisting hundred-thousands atoms that constitute macromolecular machinery life. Life not static, and unravelling structure dynamics most important reactions in chemistry biology essential uncover their mechanism. Many these reactions, including photosynthesis which drives our biosphere, are light induced occur on...
Compact laser-driven accelerators are versatile and powerful tools of unarguable relevance on societal grounds for the diverse purposes science, health, security, technology because they bring enormous practicality to state-of-the-art achievements conventional radio-frequency accelerators. Current benchmarking laser-based technologies rely a medium assist light-matter interaction, which impose material limitations or strongly inhomogeneous fields. The advent few cycle ultra-intense radially...
Ultrashort electron beams with narrow energy spread, high charge, and low jitter are essential for resolving phase transitions in metals, semiconductors, molecular crystals. These semirelativistic beams, produced by phototriggered guns, also injected into accelerators x-ray light sources. The achievable resolution of these time-resolved diffraction or experiments has been hindered surface field timing limitations conventional RF which thus far <200 MV/m >96 fs, respectively. A gun driven...
We present the first demonstration of THz-driven bunch compression and timing stabilization a few-fC relativistic electron beam with kinetic energy 2.5 MeV using quasi-single-cycle strong field THz radiation in shorted parallel-plate structure. Compression by nearly factor 3 produced 39 fs rms length reduction jitter more than 2, to 31 rms, offering significant improvement performance for applications like ultrafast diffraction. This technique provides critical step towards unprecedented...
We demonstrate single-shot temporal characterization of relativistic electron bunches using single-cycle terahertz (THz) field streaking. A transverse deflecting structure consisting a metal slit enables efficient coupling the THz and bunch. The intrinsically stable carrier envelope phase strong gradient pulses allow simultaneous, self-calibrated determination time-of-arrival with subfemtosecond precision bunch duration single-femtosecond precision, respectively, opening up new opportunities...
The International Linear Collider (ILC) is on the table now as a new global energy-frontier accelerator laboratory taking data in 2030s. ILC addresses key questions for our current understanding of particle physics. It based proven technology. Its experiments will challenge Standard Model physics and provide window to look beyond it. This document brings story up date, emphasizing its strong motivation, readiness construction, opportunity it presents US community.
The general concept of radiation therapy used in conventional cancer treatment is to increase the therapeutic index by creating a physical dose differential between tumors and normal tissues through precision targeting, image guidance, beams that deliver with high conformality, e.g., protons ions. However, cure are still limited tissue toxicity, corresponding side effects. A fundamentally different paradigm for increasing has emerged recently, supported preclinical research, based on FLASH...
Abstract Construction of an e + - Higgs factory has been identified as a major goal for particle physics. Such collider will offer precise measurements the bosons couplings to other particles. A extendable in energy can also establish self-coupling, measure coupling top quark, and expand reach probe new phenomena. We propose strategy energy-extendable based on linear accelerator technology. This offers compact cost-effective design that could be realized project US. The core technologies...
A model for terahertz (THz) generation by optical rectification using tilted-pulse-fronts is developed. It simultaneously accounts in two spatial dimensions (2-D) (i) the spatio-temporal variations of pump pulse imparted tilted-pulse-front setup, (ii) nonlinear coupled interaction THz and radiation, (iii) self-phase modulation (iv) stimulated Raman scattering. The validated quantitative agreement with experiments analytic calculations. We show that beam significantly broadened...
We report the experimental demonstration of a mm-wave electron accelerating structure powered by high-power rf source. demonstrate reliable coupling an unprecedented power—up to 575 kW into accelerator using quasi-optical setup. This standing wave consists single-cell copper cavity and Gaussian TM01 mode converter. The is 110 GHz, 10-ns long pulses. These pulses are chopped from 3 ms gyrotron oscillator laser-driven silicon switch. show high gradient up 230 MV/m that corresponds peak surface...
Abstract The ability to shape photon emission facilitates strong photon-mediated interactions between disparate physical systems, thereby enabling applications in quantum information processing, simulation and communication. Spectral control solid state platforms such as color centers, rare earth ions, dots is particularly attractive for realizing on-chip. Here we propose the use of frequency-modulated optical transitions spectral engineering single emission. Using a scattering-matrix...
We present a proposal for cold copper distributed coupling accelerator that can provide rapid route to precision Higgs physics with compact 8 km footprint. This is based on recent advances increase the efficiency and operating gradient of normal conducting accelerator. technology also provides an $e^{+}e^{-}$ collider path at multi-TeV energies. In this article, we describe our vision near-term R&D program needed pursue it.
Ultrafast electron diffraction using MeV energy beams(MeV-UED) has enabled unprecedented scientific opportunities in the study of ultrafast structural dynamics a variety gas, liquid and solid state systems. Broad applications usually pose different requirements for probe properties. Due to complex, nonlinear correlated nature accelerator systems, beam property optimization is time-taking process often relies on extensive hand-tuning by experienced human operators. Algorithm based efficient...
A compact low-level RF (LLRF) control system based on system-on-chip (RFSoC) technology has been designed for the Advanced Concept Compact Electron Linear-accelerator (ACCEL) program, which challenging requirements in both performance and size, weight power consumption (SWaP). The LLRF solution employs direct sampling technique of RFSoC, samples signals directly without any analogue up down conversion. Compared with conventional heterodyne architecture used linear accelerator (LINAC),...
We have measured fully differential single ionization cross sections for 75 keV $p+\mathrm{He}$ collisions. At this relatively small projectile velocity, signatures of the projectile--residual-target-ion interaction, which are not observable fast projectiles and electron impact, revealed rather sensitively. In fact, interaction appears to be more important than postcollision so far was assumed most factor in higher-order effects slow ion impact. These features well reproduced by our...
Abstract Femtosecond electron bunches with keV energies and eV energy spread are needed by condensed matter physicists to resolve state transitions in carbon nanotubes, molecular structures, organic salts charge density wave materials. These semirelativistic sources not only of interest for ultrafast diffraction, but also energy-loss spectroscopy as a seed x-ray FELs. Thus far, the output (hence pulse duration) guns has been limited achievable electric field at surface emitter, which is 10...