A5057414101- Laser-Plasma Interactions and Diagnostics
- Laser-Matter Interactions and Applications
- Laser Design and Applications
- Laser-induced spectroscopy and plasma
- Advanced Fiber Laser Technologies
- Particle Accelerators and Free-Electron Lasers
- Spectroscopy and Laser Applications
- Photorefractive and Nonlinear Optics
- Photonic and Optical Devices
- Advanced X-ray Imaging Techniques
- Particle accelerators and beam dynamics
- Ferroelectric and Piezoelectric Materials
- Atmospheric Ozone and Climate
- Advanced Optical Sensing Technologies
- Solid State Laser Technologies
- Photonic Crystal and Fiber Optics
- Particle Detector Development and Performance
- Pulsed Power Technology Applications
- Analytical Chemistry and Sensors
- Atmospheric and Environmental Gas Dynamics
- Mass Spectrometry Techniques and Applications
- Superconducting Materials and Applications
- Advanced Optical Imaging Technologies
- Electron and X-Ray Spectroscopy Techniques
- Atomic and Molecular Physics
Cockcroft Institute
2019-2024
University of Liverpool
2019-2024
Newcastle University
2006-2023
University of Oxford
2004-2018
European Organization for Nuclear Research
2014
University of Waterloo
2012
Science Oxford
2012
Imperial College London
1997-1999
We present experiments and numerical simulations which demonstrate that fully ionized, low-density plasma channels could be formed by hydrodynamic expansion of columns produced optical field ionization. Simulations the in hydrogen an axicon lens show generation 200 mm long with axial densities order ${n}_{\mathrm{e}}(0)=1\ifmmode\times\else\texttimes\fi{}{10}^{17}\phantom{\rule{0.16em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}3}$ lowest-order modes spot size...
We demonstrate experimentally the resonant excitation of plasma waves by trains laser pulses. also take an important first step to achieving energy recovery accelerator showing that unused wakefield can be removed out-of-resonance trailing pulse. The measured wakefields are found in excellent agreement with analytical and numerical models linear regime. Our results indicate a promising direction for highly controlled, GeV-scale laser-plasma accelerators operating at multi-kilohertz...
Laser-driven plasma accelerators can generate accelerating gradients three orders of magnitude larger than radio-frequency and have achieved beam energies above 1 GeV in centimetre long stages. However, the pulse repetition rate wall-plug efficiency laser is limited by driving to less approximately Hz 0.1% respectively. Here we investigate prospects for exciting wave with trains low-energy pulses rather a single high-energy pulse. Resonantly wakefield this way would enable use different...
A novel scheme for the focusing of high-energy leptons in future linear colliders was proposed 2001 [P. Raimondi and A. Seryi, Phys. Rev. Lett. 86, 3779 (2001)]. This has many advantageous properties over previously studied schemes, including being significantly shorter a given energy having better bandwidth. Experimental results from ATF2 accelerator at KEK are presented that validate operating principle such by demonstrating demagnification 1.3 GeV electron beam down to below 65 nm height...
We demonstrate through experiments and numerical simulations that low-density, low-loss, meter-scale plasma channels can be generated by employing a conditioning laser pulse to ionize the neutral gas collar surrounding hydrodynamic optical-field-ionized (HOFI) channel. use particle-in-cell show leading edge of ionizes generate deep, low-loss channel which guides bulk itself as well any subsequently injected pulses. In proof-of-principle experiments, we conditioned HOFI (CHOFI) waveguides...
Hydrodynamic optically-field-ionized (HOFI) plasma channels up to 100 mm long are investigated. Optical guiding is demonstrated of laser pulses with a peak input intensity 6×1017 W cm−2 through on-axis densities measured interferometrically be as low ne0=(1.0±0.3)×1017 cm−3. Guiding also observed at lower axial densities, which inferred from magneto-hydrodynamic simulations approximately 7×1016 Measurements the power attenuation lengths shown in good agreement those calculated transverse...
We propose a method for the complete characterization of attosecond duration electromagnetic pulses produced by high harmonic generation in an atomic gas. Our is based on self-referencing spectral interferometry two spectrally sheared extreme ultraviolet pulses, which achieved pumping source with optical driving pulses. The resulting interferogram contains sufficient information to completely reconstruct temporal behavior electric field. demonstrate that such feasible, and outline possible...
This document provides detailed information on the status of Advanced and Novel Accelerators techniques describes steps that need to be envisaged for their implementation in future accelerators, particular high energy physics applications. It complements overview prepared update European Strategy particle physics, a description field. The scientific priorities community are described each technique acceleration able achieve accelerating gradient GeV~range or above. ALEGRO working group...
We demonstrate optical guiding of high-intensity laser pulses in long, low-density hydrodynamic optical-field-ionized (HOFI) plasma channels. An axicon lens is used to generate HOFI channels with on-axis electron densities as low ${n}_{e}(0)=1.5\ifmmode\times\else\texttimes\fi{}{10}^{17}\text{ }\text{ }{\mathrm{cm}}^{\ensuremath{-}3}$ and matched spot sizes the range $20\text{ }\ensuremath{\mu}\mathrm{m}\ensuremath{\lesssim}{W}_{M}\ensuremath{\lesssim}40\text{ }\ensuremath{\mu}\mathrm{m}$....
In multi-pulse laser wakefield acceleration (MP-LWFA) a plasma wave is driven by train of low-energy pulses separated the period, an approach which offers route to driving accelerators with high efficiency and at pulse repetition rates using emerging technologies such as fibre thin-disk lasers. Whilst these are in development, proof-of-principle tests MP-LWFA require be generated from single, high-energy ultrafast pulse. Here we demonstrate generation trains up 7 separations range 150–170 fs...
The 2ν5 C–H stretching band of formaldehyde has been studied by cavity enhanced absorption spectroscopy near 1.76 μm using the output an external diode laser. Strong individual transitions have spectroscopically identified, and cross section air broadening parameter measured for QR1(10) line at 5676.21 cm−1, a wavenumber which interference from atmospheric CH4 other constituents is minimal. integrated found to be 5.7 ± 0.6 × 10−22 cm2 pressure coefficient 295 K 3.93 MHz Torr−1 (half width...
In recent years, hydrodynamic optical-field-ionized (HOFI) channels have emerged as a promising technique to create laser waveguides suitable for guiding tightly focused pulses in plasma, needed laser-plasma accelerators. While experimental advances HOFI continue be made, the underlying mechanisms and roles of main parameters remain largely unexplored. this paper, we propose start-to-end simulation pipeline channel formation resulting use it explore physics tunability channels. This approach...
A tunable diode laser and a low finesse optical cavity are used to probe formaldehyde on four selected rotational transitions within its 2ν5 overtone band around 1.76 μm by enhanced absorption spectroscopy (CEAS). Pressure broadening coefficients for these in the presence of variety gases (He, Ne, Ar, Kr, N2, O2 H2O, also CH2O itself) have been determined. The variation pressure cross sections with molecular parameters colliding partners is discussed terms multipole interactions compared...
A train of laser pulses guided by a 100-mm-long, all-optical plasma channel resonantly excites large amplitude wave. Pulse trains similar kind could be generated joule-scale thin-disk lasers, offering route to driving GeV-scale accelerators at kilohertz pulse repetition rates.
A laser-wire transverse electron beam size measurement system has been constructed and operated at the Accelerator Test Facility (ATF) extraction line KEK. The construction of is described in detail along with environment ATF related to laser wire. special set optics was developed generate an approximately $1\text{ }\text{ }\ensuremath{\mu}\mathrm{m}$ vertical focus location. results our operation are presented, where a minimum rms $4.8\ifmmode\pm\else\textpm\fi{}0.3\text{ measured, smaller...
We review the requirements for achieving full phase and amplitude characterization of attosecond X-ray pulses propose several methods carrying out such measurements. show via numerical simulation that these techniques are capable retrieving field information compare their performance ease implementation.