Griffin Glenn

All Publications

• Improved large-energy-range magnetic electron-positron spectrometer for experiments with the Texas Petawatt Laser JOURNAL OF INSTRUMENTATION Glenn, G. D., Tiwari, G., Dyer, G., Curry, C. B., Donovan, M. E., Gaul, E., Gauthier, M., Glenzer, S. H., Gordon, J., Hegelich, B. M., Martinez, M., McCary, E., Spinksa, M., Ditmire, T. 2019; 14

  View details for DOI 10.1088/1748-0221/14/03/P03012

  View details for Web of Science ID 000460721500009

• Diamond formation kinetics in shock-compressed C─H─O samples recorded by small-angle x-ray scattering and x-ray diffraction. Science advances He, Z., Rodel, M., Lutgert, J., Bergermann, A., Bethkenhagen, M., Chekrygina, D., Cowan, T. E., Descamps, A., French, M., Galtier, E., Gleason, A. E., Glenn, G. D., Glenzer, S. H., Inubushi, Y., Hartley, N. J., Hernandez, J., Heuser, B., Humphries, O. S., Kamimura, N., Katagiri, K., Khaghani, D., Lee, H. J., McBride, E. E., Miyanishi, K., Nagler, B., Ofori-Okai, B., Ozaki, N., Pandolfi, S., Qu, C., Ranjan, D., Redmer, R., Schoenwaelder, C., Schuster, A. K., Stevenson, M. G., Sueda, K., Togashi, T., Vinci, T., Voigt, K., Vorberger, J., Yabashi, M., Yabuuchi, T., Zinta, L. M., Ravasio, A., Kraus, D. 2022; 8 (35): eabo0617

  Abstract

  Extreme conditions inside ice giants such as Uranus and Neptune can result in peculiar chemistry and structural transitions, e.g., the precipitation of diamonds or superionic water, as so far experimentally observed only for pure C─H and H2O systems, respectively. Here, we investigate a stoichiometric mixture of C and H2O by shock-compressing polyethylene terephthalate (PET) plastics and performing in situ x-ray probing. We observe diamond formation at pressures between 72 ± 7 and 125 ± 13 GPa at temperatures ranging from ~3500 to ~6000 K. Combining x-ray diffraction and small-angle x-ray scattering, we access the kinetics of this exotic reaction. The observed demixing of C and H2O suggests that diamond precipitation inside the ice giants is enhanced by oxygen, which can lead to isolated water and thus the formation of superionic structures relevant to the planets' magnetic fields. Moreover, our measurements indicate a way of producing nanodiamonds by simple laser-driven shock compression of cheap PET plastics.

  View details for DOI 10.1126/sciadv.abo0617

  View details for PubMedID 36054354

• Investigation of hard x-ray emissions from terawatt laser-irradiated foils at the Matter in Extreme Conditions instrument of the Linac Coherent Light Source JOURNAL OF INSTRUMENTATION Fletcher, L. B., Curry, C. B., Gauthier, M., Glenn, G. D., Chen, Z., Cunningham, E., Descamps, A., Frost, M., Galtier, E. C., Heimann, P., Kim, J. B., Mo, M., Ofori-Okai, B. K., Peebles, J., Seiboth, F., Treffert, F., Dyer, G. M., McBride, E. E., Glenzer, S. H. 2022; 17 (4)

  View details for DOI 10.1088/1748-0221/17/04/T04004

  View details for Web of Science ID 000819866900015

• 2D monochromatic x-ray imaging for beam monitoring of an x-ray free electron laser and a high-power femtosecond laser REVIEW OF SCIENTIFIC INSTRUMENTS Sawada, H., Trzaska, J., Curry, C. B., Gauthier, M., Fletcher, L. B., Jiang, S., Lee, H. J., Galtier, E. C., Cunningham, E., Dyer, G., Daykin, T. S., Chen, L., Salinas, C., Glenn, G. D., Frost, M., Glenzer, S. H., Ping, Y., Kemp, A. J., Sentoku, Y. 2021; 92 (1): 013510

  Abstract

  In pump-probe experiments with an X-ray Free Electron Laser (XFEL) and a high-power optical laser, spatial overlap of the two beams must be ensured to probe a pumped area with the x-ray beam. A beam monitoring diagnostic is particularly important in short-pulse laser experiments where a tightly focused beam is required to achieve a relativistic laser intensity for generation of energetic particles. Here, we report the demonstration of on-shot beam pointing measurements of an XFEL and a terawatt class femtosecond laser using 2D monochromatic Kα imaging at the Matter in Extreme Conditions end-station of the Linac Coherent Light Source. A thin solid titanium foil was irradiated by a 25-TW laser for fast electron isochoric heating, while a 7.0 keV XFEL beam was used to probe the laser-heated region. Using a spherical crystal imager (SCI), the beam overlap was examined by measuring 4.51 keV Kα x rays produced by laser-accelerated fast electrons and the x-ray beam. Measurements were made for XFEL-only at various focus lens positions, laser-only, and two-beam shots. Successful beam overlapping was observed on ∼58% of all two-beam shots for 10 μm thick samples. It is found that large spatial offsets of laser-induced Kα spots are attributed to imprecise target positioning rather than shot-to-shot laser pointing variations. By applying the Kα measurements to x-ray Thomson scattering measurements, we found an optimum x-ray beam spot size that maximizes scattering signals. Monochromatic x-ray imaging with the SCI could be used as an on-shot beam pointing monitor for XFEL-laser or multiple short-pulse laser experiments.

  View details for DOI 10.1063/5.0014329

  View details for Web of Science ID 000630907400004

  View details for PubMedID 33514225

• Optimization of radiochromic film stacks to diagnose high-flux laser-accelerated proton beams REVIEW OF SCIENTIFIC INSTRUMENTS Curry, C. B., Dunning, C. S., Gauthier, M., Chou, H. J., Fiuza, F., Glenn, G. D., Tsui, Y. Y., Bazalova-Carter, M., Glenzer, S. H. 2020; 91 (9): 093303

  Abstract

  Here, we extend flatbed scanner calibrations of GafChromic EBT3, MD-V3, and HD-V2 radiochromic films using high-precision x-ray irradiation and monoenergetic proton bombardment. By computing a visibility parameter based on fractional errors, optimal dose ranges and transitions between film types are identified. The visibility analysis is used to design an ideal radiochromic film stack for the proton energy spectrum expected from the interaction of a petawatt laser with a cryogenic hydrogen jet target.

  View details for DOI 10.1063/5.0020568

  View details for Web of Science ID 000573944100003

  View details for PubMedID 33003776

• Beam distortion effects upon focusing an ultrashort petawatt laser pulse to greater than 10(22) W/cm(2) OPTICS LETTERS Tiwari, G., Gaul, E., Martinez, M., Dyer, G., Gordon, J., Spinks, M., Toncian, T., Bowers, B., Jiao, X., Kupfer, R., Lisi, L., McCary, E., Roycroft, R., Yandow, A., Glenn, G. D., Donovan, M., Ditmire, T., Hegelich, B. M. 2019; 44 (11): 2764–67

  View details for DOI 10.1364/OL.44.002764

  View details for Web of Science ID 000469838100039