Johan Frenje

Senior Research Scientist, Head of the HEDP Division at MIT PSFC

Massachusetts Institute of Technology
Country flagUnited States

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

UNITED STATES
View details

Gabriel Rigon

Assistant Professor

Ecole Polytechnique

FRANCE
View details

Alex Zylstra

Massachusetts Institute of Technology

UNITED STATES
View details

R. Florido

-

SPAIN
View details
ApplyKite TwinLearns as you apply

Make your next move.

Prepare your application

Review drafts before you send them.