Imperial College London

Dr Alvaro Sanchez Gonzalez

Faculty of Natural SciencesDepartment of Physics

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Contact

 

+44 (0)20 7594 7887a.sanchez-gonzalez13 Website CV

 
 
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Location

 

02Huxley BuildingSouth Kensington Campus

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Summary

 

Publications

Publication Type
Year
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9 results found

Hutchison CDM, Cordon-Preciado V, Morgan RML, Nakane T, Ferreira J, Dorlhiac G, Sanchez-Gonzalez A, Johnson AS, Fitzpatrick A, Fare C, Marangos JP, Yoon CH, Hunter MS, DePonte DP, Boutet S, Owada S, Tanaka R, Tono K, Iwata S, van Thor JJet al., 2017, X-ray Free Electron Laser Determination of Crystal Structures of Dark and Light States of a Reversibly Photoswitching Fluorescent Protein at Room Temperature., International Journal of Molecular Sciences, Vol: 18, ISSN: 1422-0067

The photochromic fluorescent protein Skylan-NS (Nonlinear Structured illumination variant mEos3.1H62L) is a reversibly photoswitchable fluorescent protein which has an unilluminated/ground state with an anionic and cis chromophore conformation and high fluorescence quantum yield. Photo-conversion with illumination at 515 nm generates a meta-stable intermediate with neutral trans-chromophore structure that has a 4 h lifetime. We present X-ray crystal structures of the cis (on) state at 1.9 Angstrom resolution and the trans (off) state at a limiting resolution of 1.55 Angstrom from serial femtosecond crystallography experiments conducted at SPring-8 Angstrom Compact Free Electron Laser (SACLA) at 7.0 keV and 10.5 keV, and at Linac Coherent Light Source (LCLS) at 9.5 keV. We present a comparison of the data reduction and structure determination statistics for the two facilities which differ in flux, beam characteristics and detector technologies. Furthermore, a comparison of droplet on demand, grease injection and Gas Dynamic Virtual Nozzle (GDVN) injection shows no significant differences in limiting resolution. The photoconversion of the on- to the off-state includes both internal and surface exposed protein structural changes, occurring in regions that lack crystal contacts in the orthorhombic crystal form.

Journal article

Sanchez Gonzalez A, Micaelli P, Olivier C, Barillot TR, Ilchen I, Lutman AA, Marinelli A, Maxwell T, Achner A, Agåker M, Berrah N, Bostedt C, Bozek JD, Buck J, Bucksbaum PH, Carron Montero S, Cooper B, Cryan JP, Dong M, Feifel R, Frasinski LJ, Fukuzawa H, Galler A, Hartmann G, Hartmann N, Helml W, Johnson AS, Knie A, Lindahl AO, Liu J, Motomura K, Mucke M, O'Grady C, Rubensson J-E, Simpson ER, Squibb RJ, Såthe C, Ueda K, Vacher M, Walke DJ, Zhaunerchyk V, Coffee RN, Marangos JPet al., 2017, Accurate prediction of X-ray pulse properties from a free-electron laser using machine learning, Nature Communications, Vol: 8, ISSN: 2041-1723

Free-electron lasers providing ultra-short high-brightness pulses of X-ray radiation have great potential for a wide impact on science, and are a critical element for unravelling the structural dynamics of matter. To fully harness this potential, we must accurately know the X-ray properties: intensity, spectrum and temporal profile. Owing to the inherent fluctuations in free-electron lasers, this mandates a full characterization of the properties for each and every pulse. While diagnostics of these properties exist, they are often invasive and many cannot operate at a high-repetition rate. Here, we present a technique for circumventing this limitation. Employing a machine learning strategy, we can accurately predict X-ray properties for every shot using only parameters that are easily recorded at high-repetition rate, by training a model on a small set of fully diagnosed pulses. This opens the door to fully realizing the promise of next-generation high-repetition rate X-ray lasers.

Journal article

Damiani D, Dubrovin M, Gaponenko I, Kroeger W, Lane TJ, Mitra A, O'Grady CP, Salnikov A, Sanchez-Gonzalez A, Schneider D, Yoon CHet al., 2016, Linac Coherent Light Source data analysis using psana, JOURNAL OF APPLIED CRYSTALLOGRAPHY, Vol: 49, Pages: 672-679, ISSN: 0021-8898

Journal article

Simpson ER, Sanchez-Gonzalez A, Austin DR, Diveki Z, Hutchinson SEE, Siegel T, Ruberti M, Averbukh V, Miseikis L, Strüber C, Chipperfield L, Marangos JPet al., 2015, The response of a neutral atom to a strong laser field probed by transient absorption near the ionisation threshold

We present transient absorption spectra of an extreme ultraviolet attosecondpulse train in helium dressed by an 800 nm laser field with intensity rangingfrom $2\times10^{12}$ W/cm$^2$ to $2\times10^{14}$ W/cm$^2$. The energy rangeprobed spans 16-42 eV, straddling the first ionisation energy of helium (24.59eV). By changing the relative polarisation of the dressing field with respectto the attosecond pulse train polarisation we observe a large change in themodulation of the absorption reflecting the vectorial response to the dressingfield. With parallel polarized dressing and probing fields, we observesignificant modulations with periods of one half and one quarter of thedressing field period. With perpendicularly polarized dressing and probingfields, the modulations of the harmonics above the ionisation threshold aresignificantly suppressed. A full-dimensionality solution of the single-atomtime-dependent Schr\"odinger equation obtained using the recently developedab-initio time-dependent B-spline ADC method reproduce some of ourobservations.

Working paper

Sanchez-Gonzalez A, Barillot TR, Squibb RJ, Kolorenc P, Agaker M, Averbukh V, Bearpark MJ, Bostedt C, Bozek JD, Bruce S, Montero SC, Coffee RN, Cooper B, Cryan JP, Dong M, Eland JHD, Fang L, Fukuzawa H, Guehr M, Ilchen M, Johnsson AS, Liekhus-S C, Marinelli A, Maxwell T, Motomura K, Mucke M, Natan A, Osipov T, Ostlin C, Pernpointner M, Petrovic VS, Robb MA, Sathe C, Simpson ER, Underwood JG, Vacher M, Walke DJ, Wolf TJA, Zhaunerchyk V, Rubensson J-E, Berrah N, Bucksbaum PH, Ueda K, Feifel R, Frasinski LJ, Marangos JPet al., 2015, Auger electron and photoabsorption spectra of glycine in the vicinity of the oxygen K-edge measured with an X-FEL, JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS, Vol: 48, ISSN: 0953-4075

Journal article

Rohringer N, Kimberg V, Weninger C, Sanchez Gonzalez A, Lutman A, Maxwell T, Bostedt C, Carron Monterro S, Lindahl OA, Ilchen M, Coffee NR, Bozek DJ, Krzywinski J, Kierspel T, Mullins T, Kupper J, Erk B, Rolles D, Mucke DO, London AR, Purvis M, Ryan D, Rocca JJ, Feifel R, Squibb R, Zhaunerchyk V, Sathe C, Agaker M, Mucke M, Nordgren J, Rubensson EJet al., 2015, Stimulated X-Ray raman scattering with free-electron laser sources, X-Ray Lasers 2014 Proceedings of the 14th International Conference on X-Ray Lasers, Editors: Rocca, Menoni, Marconi, Publisher: Springer, Pages: 201-207, ISBN: 9783319195216

The scope of ICXRL 2014 included, but was not limited to: Laser-pumped X-ray lasers Discharge excitation and other X-ray laser pumping methods Injection/seeding of X-ray amplifiers New lasing transitions and novel X-ray laser schemes High ...

Book chapter

Liekhus-Schmaltz CE, Tenney I, Osipov T, Sanchez-Gonzalez A, Berrah N, Boll R, Bomme C, Bostedt C, Bozek JD, Carron S, Coffee R, Devin J, Erk B, Ferguson KR, Field RW, Foucar L, Frasinski LJ, Glownia JM, Guehr M, Kamalov A, Krzywinski J, Li H, Marangos JP, Martinez TJ, McFarland BK, Miyabe S, Murphy B, Natan A, Rolles D, Rudenko A, Siano M, Simpson ER, Spector L, Swiggers M, Walke D, Wang S, Weber T, Bucksbaum PH, Petrovic VSet al., 2015, Ultrafast isomerization initiated by X-ray core ionization, Nature Communications, Vol: 6, ISSN: 2041-1723

Rapid proton migration is a key process in hydrocarbon photochemistry. Charge migration and subsequent proton motion can mitigate radiation damage when heavier atoms absorb X-rays. If rapid enough, this can improve the fidelity of diffract-before-destroy measurements of biomolecular structure at X-ray-free electron lasers. Here we study X-ray-initiated isomerization of acetylene, a model for proton dynamics in hydrocarbons. Our time-resolved measurements capture the transient motion of protons following X-ray ionization of carbon K-shell electrons. We Coulomb-explode the molecule with a second precisely delayed X-ray pulse and then record all the fragment momenta. These snapshots at different delays are combined into a ‘molecular movie’ of the evolving molecule, which shows substantial proton redistribution within the first 12 fs. We conclude that significant proton motion occurs on a timescale comparable to the Auger relaxation that refills the K-shell vacancy.

Journal article

Simpson ER, Sanchez-Gonzalez A, Siegel T, Diveki Z, Hutchinson SEE, Miseikis L, Strueber C, Austin DR, Marangos JPet al., 2015, A beamline for attosecond pump-probe experiments: Towards tracking ultrafast electron dynamics in atoms and molecules, Conference on Ultrafast Nonlinear Imaging and Spectroscopy III, Publisher: SPIE-INT SOC OPTICAL ENGINEERING, ISSN: 0277-786X

Conference paper

de Gracia P, Dorronsoro C, Sánchez-González Á, Sawides L, Marcos Set al., 2013, Experimental Simulation of Simultaneous Vision, Investigative Opthalmology & Visual Science, Vol: 54, Pages: 415-415, ISSN: 1552-5783

Journal article

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