Johan Frenje
Senior Research Scientist, Head of the HEDP Division at MIT PSFC
Research Interests
Explore related searches
Contact this professor
Get a free first email built on one of their papers, ready for you to edit and send yourself.
About
Johan Frenje is a Senior Research Scientist and Head of the HEDP Division at the Massachusetts Institute of Technology (MIT), USA. His research areas encompass inertial confinement fusion, diagnostics for high energy density physics, and the development of advanced spectrometers. Recent publications include studies on the performance of exploding pusher implosions, neutron diagnostic systems for tokamaks, and the measurement of electron temperature distributions in fusion experiments.
Articles (14)
Year:
2025
Year:
2025
Kr L-shell spectroscopy modeling results are discussed in this paper, focusing on the n = 4 to n = 2 line transitions of Be- and Li-like Kr ions. Collisional radiative atomic kinetic and Stark-broadened spectral line shape calculations show electron temperature Te and density ne sensitivity in the spectrum. The combination of the Te dependence due to the relative intensity of Be-like to Li-like line emissions in the range from 1.5 to 3 keV and the ne sensitivity from the Stark broadening effect on the line shapes in the range from 5×1023 to 2×1024/ cc results in a spectrum that can be employed to diagnose Te and ne. Two different collisional radiative atomic kinetic models i.e., Prismspect [J. J. MacFarlane, et al., Int. Fusion Sci. Appl. Conf. Proc. 457 (2003)] and ABAKO [Florido, et al., PRE, 80, 056402 (2009)] produce similar results in level populations and spectra. In x-ray spectroscopy of implosion cores, this Kr L-shell spectrum may prove useful in an intermediate Te range in which Ar is too ionized for its K-shell to be of diagnostic value and Kr is not ionized enough for its K-shell emission to be useful.
Year:
2024
Year:
2024
Year:
2024
Year:
2024
Year:
2024
Year:
2024
Year:
2024
Year:
2023
Year:
2023
Year:
2023
Year:
2023
Year:
2022
Collaborators (4)
Georg Berg
Research Professor
University of Notre Dame
Gabriel Rigon
Assistant Professor
Ecole Polytechnique
Alex Zylstra
Massachusetts Institute of Technology
R. Florido
-
Make your next move.
Prepare your application
Review drafts before you send them.