Alumni Profiles

Ryan Childers

• Program Years: 2019-2023
• Academic Institution: University of Nevada, Reno
• Field of Study: Plasma Spectroscopy
• Academic Advisor: Alla Safronova
• Residencies:
  Sandia National Laboratories, New Mexico (2019)
  Sandia National Laboratories, New Mexico (2021)
• Degree(s):
  Ph.D Physics, University of Nevada, Reno (2023);
  M.Sc. Physics, University of Nevada, Reno (2017);
  B.S. Physics, University of Nevada, Reno (2015);
  B.S. Psychology, University of Nevada, Reno (2011)

Current Status

• Status: Research Physicist, Radiation Hydrodynamics Branch - U.S. Naval Research Laboratory, Washington, DC
• Research Area: Plasma Physics: atomic ionization kinetics & x-ray spectroscopy

Publications

Publications

-R.R. Childers, A.S. Safronova, V.L. Kantsyrev, A. Stafford, A. K. Gill, "K-shell radiation and bright spot characteristics of high-energy-density Fe-Cr-Ni plasmas influenced by X-pinch load geometry". Quant. Spectrosc. Radiat. Transfer, 303, 108586 (2023)

-A.S. Safronova, A. Stafford, A.K. Gill, R.R. Childers, "Polarization of Hard X-ray Dielectronic Satellite Line Emission from Na-like W ions", Journal of Quantitative Spectroscopy and Radiative Transfer 272, 107788 (2021).

-R. R. Childers, E. E. Petkov, V. L. Kantsyrev, A. S. Safronova, A. Stafford, V. V. Shlyaptseva, I. K. Shrestha, K. A. Schultz, C. J. Butcher, "X-ray Line Polarization of Ne-like Mo Spectra from X-pinch Plasmas", IEEE Trans. Plas. Sci., 46, pp. 3820-28 (2018)

-R. R. Childers, "Application of X-ray Line Polarization to High-Energy-Density X-pinch Ne-like Mo Plasmas", Thesis - Master of Science, University of Nevada, Reno, December 2017.

Proceedings

A.K. Gill, A.S. Safronova, R.R. Childers, V.L. Kantsyrev, V.V. Shlyaptseva, "Theoretical Study of Gas-puff and Laser-irradiated Gas Jet M-shell Xenon Experiments Radiating Between 9 and 14 Ã…", IEEE International Conference on Plasma Science (ICOPS), 2021, doi: 10.1109/ICOPS36761.2021.9588610.

R. R. Childers, A. S. Safronova, V. L. Kantsyrev, R. Plotkin, A. Stafford and D. J. Ampleford, "Exploring the Spectral Signatures of Inner-Shell Excitation Mechanisms in Nonthermal Z-Pinch Plasmas," 2020 IEEE International Conference on Plasma Science (ICOPS), Singapore, 2020, pp. 550-550, doi:10.1109/ICOPS37625.2020.9717742.

A.S. Safronova, V.L. Kantsyrev, R.R. Childers, A. Stafford, V. V. Shlyaptseva, I. Shrestha, C. J. Butcher, E.E. Petkov, J.L. Giuliani, "X-Ray Radiation from Compact Tungsten Wire Arrays at 1 MA Current," 2020 IEEE International Conference on Plasma Science (ICOPS), Singapore, 2020, pp. 330-330, doi: 10.1109/ICOPS37625.2020.9717752.


Presentations/Posters

-R.R. Childers, "Studies of Nonthermal Kinetics and Radiative Properties of High Energy Density Z-Pinch Plasmas with Applications to a Newly Proposed Advanced Hybrid Atomic Model", Plasma Physics Division Seminar, U.S. Naval Research Laboratory, Washington DC, Feb. 23, 2023 (Invited Talk)

-R. R. Childers, A. S. Safronova, V. L. Kantsyrev, A. K. Gill, C. J. Butcher, "Nonthermal Kinetics and Radiative Properties of High Energy Density Pulsed Power Plasmas", 2023 NNSA Stewardship Science Academic Program (SSAP) Symposium, February 14-16, 2023; Santa Fe, NM. (Poster presentation)

-A.S. Safronova, V.L. Kantsyrev, C.J. Butcher, R.R. Childers, A. Gill, A. Stafford, "Understanding Atomic Properties in HED plasmas by Studying Line and Continuum Emission from High-Z Ions", 2023 NNSA Stewardship Science Academic Program (SSAP) Symposium, February 14-16, 2023; Santa Fe, NM (Invited Talk)

-R.R. Childers, "Development of an integrated atomic kinetic plasma code for dense plasma environments", Harold Brown Postdoctoral Fellowship Seminar, Lawrence Livermore National Laboratories, Livermore, CA, Dec. 6, 2022 (Invited Talk)

-R. R. Childers, S. B. Hansen, A. S. Safronova, D. J. Ampleford, "Monte Carlo Radiation Transport Simulation of a MagLIF Plasma Produced on Z", APS Division of Plasma Physics 2022, October 17th-21st, (Contributed Oral Talk)

-A.S. Safronova, V.L. Kantsyrev, R.R. Childers, A. Stafford, C.J. Butcher, V.V. Shlyaptseva, "Radiation from Tungsten Z-pinches influenced by using the alternating W and mid-atomic-number wires", 64th Annual Meeting of the APS Division of Plasma Physics, October 17, 2022; Spokane, WA. (Oral contributed talk)

-R. R. Childers, A.S. Safronova, V.L. Kantsyrev, C. J. Butcher, A. K. Gill, "Inner-shell Radiation Properties of Z-pinch Plasmas with Astrophysically Relevant Conditions", 2022 APS Far West Annual Meeting, October 7th-8th, 2022 (Featured Student Talk)

-R. R. Childers, S. B. Hansen, A. S. Safronova, D. J. Ampleford, "Monte Carlo Radiation Transport Simulation of Nonthermal X-ray Fluorescence in a High-Energy-Density MagLIF Plasmas Produced on Z", 2022 DOE NNSA SSGF & LRGF Annual Program Review, June 20th-23rd, 2022 (Poster)

-R. R. Childers, A. S. Safronova, V. L. Kantsyrev, A. K. Gill, A. Stafford, "Influence of X-pinch Load Geometry on Bright Spot Formation and K-shell Radiation from High Energy Density Plasmas", 2nd ZNetUS Workshop, April 21-22, 2022 (Virtual).

-A.K. Gill, A.S. Safronova, R.R. Childers, V.L. Kantsyrev, V.V. Shlyaptseva, "The Complete Spectroscopic Picture for Xenon Plasmas Radiating Between 5 and 14.5 Ã…", 2nd ZNetUS Workshop, April 21-22, 2022 (Virtual).

-A.S. Safronova, V.L. Kantsyrev, C.J. Butcher, R.R. Childers, A. Gill, A. Stafford, "Hard and Soft X-ray Line Emission from High-Z Multiply Ionized Ions Influenced by Dielectronic Recombination and Polarization from HEDLP", 2022 NNSA StewardshipScience Academic Program (SSAP) Symposium, February 15-17, 2022 (Virtual meeting). Invited Talk

-R.R. Childers, A.S. Safronova, V.L. Kantsyrev, S.B. Hansen, A.K. Gill, D.J. Ampleford, A.Stafford, "Recent Progress on the Study of Nonthermal X-rays in High-Energy-Density Z-pinch Plasmas", 2022 NNSA Stewardship Science Academic Program (SSAP) Symposium, February 15-17, 2022 (Virtual meeting). Poster presentation.

-A.K. Gill, A.S. Safronova, R.R. Childers, V.L. Kantsyrev, V.V. Shlyaptseva, "Progress on Studying X-ray Line Emission from Multiply Ionized Xenon Ions Influenced by Dielectronic Recombination and Polarization", 2022 NNSA Stewardship Science Academic Program
(SSAP) Symposium, February 15-17, 2022 (Virtual meeting). Poster presentation.

-A. S. Safronova, V. L. Kantsyrev, R. R. Childers, C. J. Butcher, A. Stafford, V. V. Shlyaptseva, E. E. Petkov, "Highlights of Spectroscopic, Imaging, and Polarization Studies at University-scale Z-pinch Generators", 14 th International Conference on Plasma Sciences and Applications (ICPSA 2021), Dec. 28-30, 2021 (Virtual meeting). Invited Talk

-A.K. Gill, A.S. Safronova, R.R. Childers, V.L. Kantsyrev, V.V. Shlyaptseva, "Theoretical Study of Gas-puff and Laser-irradiated Gas Jet M-shell Xenon Experiments Radiating Between 9 and 14 â„«", 48th IEEE International Conference on Plasma Science (ICOPS 2021, Sep. 12-16, 2021). Oral contributed talk.

-A.K. Gill, A.S. Safronova, A. Stafford, V.L. Kantsyrev, V.V. Shlyaptseva, R.R. Childers, "Atomic Processes in Highly Ionized Xenon Plasmas Radiating Between 2.5 and 14 Ã…", 52nd Annual Meeting of the APS Division of Atomic, Molecular and Optical Physics, May 31 - June 4, 2021(Virtual meeting). Oral contributed talk.

-A.S. Safronova, V.L. Kantsyrev, A. Stafford, C.J. Butcher, R.R. Childers, A.K. Gill, "Hard and Soft X-ray Line emission from High-Z Multiply Ionized Ions Influenced by Dielectronic Recombination and Polarization from HEDLP", 2021 NNSA Stewardship Science Academic Program (SSAP) Symposium, Virtual, February 16-18, 2021. Invited talk.

-R. R. Childers, A. S. Safronova, V. L. Kantsyrev, A. Stafford, A. K. Gill, "Studying Nonthermal High-Energy-Density Plasmas Using X-pinches of Different Load Geometry", 2021 NNSA Stewardship Science Academic Program (SSAP) Symposium, Virtual, February 16-18, 2021. Poster presentation.

-A.K. Gill, A.S. Safronova, A. Stafford, V.L. Kantsyrev, V.V. Shlyaptseva, R.R. Childers, "Atomic Processes in Highly Ionized Plasmas Radiating Between 2.5 and 14 Ã…", 2021 NNSA Stewardship Science Academic Program (SSAP) Symposium, Virtual, February 16-18, 2021. Poster presentation.

-R.R. Childers, A.S. Safronova, V.L. Kantsyrev, R. Plotkin, D.J. Ampleford, "Exploring the Spectral Signatures of Inner-shell Excitation Mechanisms in Nonthermal Z-pinch Plasmas", 47th IEEE International Conference on Plasma Science (ICOPS 2020), December 6-10, 2020 (Virtual meeting). Oral contributed talk.

-A.S. Safronova, V.L. Kantsyrev, R.R. Childers, A. Stafford, V.V. Shlyaptseva, I.K. Shrestha, C.L. Butcher, E.E. Petkov, J.L. Giuliani, "X-ray radiation from compact tungsten wire arrays at 1 MA current", 47th International Conference on Plasma Sciences (ICOPS 2020), Dec. 6-10, 2020 (Virtual meeting). Oral contributed talk.

-A. Safronova, A. Stafford, A. Gill, R. R. Childers, "Polarization of Hard X-ray Dielectronic Satellite Line Emission from Na-like W ions", 62th Annual Meeting of the APS Division of Plasma Physics (DPP20), November 9-13, 2020 (Virtual meeting). Oral contributed talk.

-R. R. Childers, A. S. Safronova, V. L. Kantsyrev, R. Plotkin, A. Stafford, D. J. Ampleford, "Influence of Load Geometry on Nonthermal Emission in High-Energy Density X-pinch Plasmas on the Zebra Generator", Annual FWS20 meeting of the APS, Oct.9-10, 2020 (Virtual meeting). Oral contributed talk.

-R. R. Childers, A. S. Safronova, V. L. Kantsyrev, R. Plotkin, "Importance of Understanding Excitation Mechanisms Driving Nonthermal Emission in Z-pinch Fe Plasmas", Z Fundamental Science Workshop, August 3-4, 2020 (Virtual Meeting). Oral contributed talk.

-R.R. Childers, A.S. Safronova, V.L.Kantsyrev, D. Ampleford, R. Plotkin, C.J. Butcher, "Understanding the excitation mechanisms driving K-shell emission in non-thermal High Energy Density Plasmas", 2020 NNSA Stewardship Science Academic Program Symposium, Washington Marriott Wardman Park Hotel, Washington DC, February 26-27, 2020. (Poster presentation).

-R.R. Childers, A. S. Safronova, V. L. Kantsyrev, A. Stafford, I. K. Shrestha, V. V. Shlyaptseva, C. J. Butcher, "Probing Non-Maxwellian Electrons in a High-Energy-Density Laboratory Plasma Using Polarization Spectroscopy", 2019 NNSA Stewardship Science Academic Program Symposium, Sheraton Albuquerque Uptown, Albuquerque, NM, February 19-20, 2019. (Poster presentation).

-A. S. Safronova, V. L. Kantsyrev, V. V. Shlyaptseva, I. K. Shrestha, U. S. Safronova, C. J. Butcher, A. Stafford, R. R. Childers, "Applications of Tungsten in Z-pinch Plasma Physics and Fusion", 1st Hawaii Meeting of Far West Section of American Phys

Awards

-Karle's Fellowship, U.S. Naval Research Laboratory (2023)
-Margaret Burbidge Award for Best Experimental Research by a Graduate Student, APS FWS (2022)
-International Conference on Plasma Science (ICOPS) Travel Grant (2020)
-DOE NNSA LRGF Fellow (2019)
-Alpha Kappa Psi Professional Business Fraternity: New Member Award (2010)
-University of Nevada, Student Ambassadors: Ambassador of the year (2009)