Background

Anton Tonchev studied nuclear physics at the Joint Institute for Nuclear Research in Dubna, Russia, where he was awarded a G.N. Flerov Fellowship. He worked as an assistant professor at Duke University for eleven years and concurrently as an adjunct associate professor at the University of North Carolina for six years. When Tonchev joined the LLNL staff in 2011, he continued his work at Duke University as an adjunct associate professor. He is currently an experimental nuclear physicist in the Nuclear & Particle Physics group at LLNL.

Research Interests

Tonchev’s research interests include nuclear structure (collective modes of excitation, giant resonances, high-spin isomeric states), nuclear dynamics (nuclear fission, gamma and particle emission) nuclear astrophysics (p- and s-processes), and nuclear applications (gamma and neutron activation analysis, radio isotope production, nuclear energy, and nuclear forensics). His research is motivated to study nuclear fission to understand how the excitation energy is distributed among the fission fragments, prompt neutron, and gamma-ray emission. At LLNL, he conducts fundamental research in the areas of nuclear structure and astrophysics to better understand the behavior of neutron-rich nuclear matter, as occurs in neutron stars or heavy nuclei.

PhD, Nuclear Physics, Joint Institute for Nuclear Research, Russia, 1995

MS, Physics, Plovdiv University, Bulgaria and Joint Institute for Nuclear Research, Russia, 1988

A.P. Tonchev, N. Tsoneva, C. Bhatiad, C.W. Arnold, S. Goriely, S.L. Hammond, J.H. Kelley, E. Kwan, H. Lenske, J. Piekarewicz, R. Raut, G. Rusev, T. Shizuma, and W. Tornow. “Pygmy and core polarization dipole modes in 206Pb: Connecting nuclear structure to stellar nucleosynthesis,” Phys. Lett. B 773, 20 (2017).

Krishichayan, M. Bhike, W. Tornow, A. P. Tonchev, and T. Kawano. “Accurate 238U(n,2n) reaction cross-section measurements from 6.5 to 14.8 MeV,” Phys. Rev. C 96, 044623 (2017).

A.P. Tonchev, J.E. Escher, N. Scielzo, P. Bedrossian, R.S. Ilieva, P. Humby, N. Cooper, P.M. Goddard, V. Werner, W. Tornow, G. Rusev, J.H. Kelley, N. Pietralla, M. Scheck, D. Savran, B. Löher, S.W. Yates, B.P. Crider, E.E. Peters, N. Tsoneva, and S. Goriely. “Capture Cross Sections on Unstable Nuclei,” EPJ Web of Conferences 146, 01013 (2017).

M. Bhike, W. Tornow, Krishichayan, and A.P. Tonchev. “Exploratory Study of Fission Product Yield Determination from Photo-Fission of 239Pu at 11 MeV with monoenergetic photons,” Phys. Rev. C 95, 024608 (2017).

A.P. Tonchev, M.A. Stoyer, J.A. Becker, R. Macri, C. Ryan, S.A. Sheets, M.E. Gooden, C.W. Arnold, E. Bond, T. Bredeweg, M.M. Fowler, G. Rusev, D.J. Vieira, J.B. Wilhelmy, W. Tornow, C.R. Howell, C. Bhatia, M. Bhike, Krishichayan, J.H. Kelley, B. Fallin, and S.W. Finch. “Energy Evolution of the Fission-Product Yields from Neutron-Induced Fission of 235U, 238U, and 239Pu: An Unexpected Observation,” Sixth International Conference on ICFN6 (2017).

B. Löher, D. Savran, T. Aumann, J. Beller, M. Bhike, N. Cooper, V. Derya, M. Duchêne, J. Endres, A. Hennig, P. Humby, J. Isaak, J.H. Kelley, M. Knörzer, N. Pietralla, V.Yu. Ponomarev, C. Romig, M. Scheck, H. Scheit, J. Silva, A.P. Tonchev, W. Tornow, F. Wamersa, H. Wellerb, V. Wernerh, A. Zilges. “The decay pattern of the Pygmy Dipole Resonance of 140Ce,” Phys. Lett. B 756, 72 (2016).

M. E. Gooden, B. Fallin, C. R. Howell, J. H. Kelley, W. Tornow, C. W. Arnold, E. M. Bond, T. A. Bredeweg, M. M. Fowler, W. A. Moody, R. S. Rundberg, G. Rusev, D. J. Vieira, J. B. Wilhelmy, J. A. Becker, R. Macri, C. Ryan, S. A. Sheets, M. A. Stoyer, and A. P. Tonchev, “Energy Dependence of Fission Product Yields from 235U, 238U and 239Pu for Incident Neutron Energies Between 0.5 and 14.8 MeV,” Nuclear Data Sheets 119, 324 (2016).

B. Champine, M. E. Gooden, Krishichayan, E. B. Norman, N. D. Scielzo, M. A. Stoyer, K. J. Thomas, A. P. Tonchev, W. Tornow, and B. S. Wang. “Measurements of the 169Tm(n,3n)167Tm cross section and the associated branching ratios in the decay of 167Tm,” Phys. Rev. C 93, 014611 (2016).

N. Benouaret, J. Beller, H. Pai, N. Pietralla, V.Yu. Ponomarev, C. Romig, L. Schnorrenberger, M. Zweidinger, M. Scheck, J. Isaak, D. Savran, K. Sonnabend, R. Raut, G. Rusev, A. P. Tonchev, W. Tornow, H. R. Weller and J. H. Kelley. “Dipole Response of the Odd-Proton Nucleus 205Tl up to the Neutron-Separation Energy,” Journal of Physics G: Nuclear and Particle Physics 43 (2016).

A.C. Hayes, G. Jungman, A. E. Schulz, M. Boswell, M. M. Fowler, G. Grim, A. Klein, R. S. Rundberg, J. B. Wilhelmy, D. Wilson, C. Cerjan, D. Schneider, S. M. Sepke, A. Tonchev, and C. Yeamans. “Reaction-in-flight neutrons as a test of stopping power in degenerate plasmas,” Phys. Plasmas 22, 082703 (2015).

A.P. Tonchev, C. Bhatia, J. Kelley, R. Raut, G. Rusev, W. Tornow and N. Tsoneva. “Nuclear Structure Studies with Gamma-Ray Beams,” EPJ Web of Conferences 93, 01030 (2015).

J. Beller, C. Stumpf, M. Scheck, N. Pietralla, D. Deleanu, D.M. Filipescu, T. Glodariu, W. Haxton, A. Idini, J.H. Kelley, E. Kwan, G. Martinez-Pinedo, R. Raut, C. Romig, R. Roth, G. Rusev, D. Savran, A.P. Tonchev, W. Tornow, J. Wagner, H.R. Weller. “Separation of the 1+/1- parity doublet in 20Ne,” Phys. Lett. B 741, 128 (2015).

• Adjunct Associate Professor at Duke University, 2012–present
• Adjunct Associate Professor at the Department of Physics and Astronomy at UNC, 2005–2011
• Assistant Professor, Duke University, 2000–2011
• G.N. Flerov Fellowship, Joint Institute for Nuclear Research, Dubna, Russia, 1995