Leo Kirsch

  • Program Year: 3
  • Academic Institution: University of California, Berkeley
  • Field of Study: Nuclear Physics
  • Academic Advisor: Karl van Bibber
  • Practicum(s):
    Los Alamos National Laboratory (2016)
  • Degree(s):
    B.S. Nuclear Engineering, University of Illinois at Urbana-Champaign, 2012

Summary of Research

This nation needs a wealth of nuclear data to ensure the safety, reliability, and predictive capabilities of the country's nuclear power reactors, medical isotope production facilities, basic science accelerators, high radiation environment electronics, and national nuclear security detection systems. The High Flux Neutron Generator at UC Berkeley is currently publishing reaction data on fission yields, positron emitting isotopes for medical imaging, elastic scattering for reactors, neutron damage to electronics, and inelastic scattering relevant to nonproliferation. I have been involved in developing this facility from construction to collaboration to colliding to counting to computation to cross-section. This work has equipped me with a wide range of expertise to confront the technical, computational, and theoretical demands of experimental physics.

I have interwoven my work on the HFNG with experimental research on nuclear reactions and structure. Humanity will never be able to measure every nuclear reaction and must rely on models that stem from our knowledge of quantum mechanics, condensed matter, and particle physics. We require a detailed description of one foundational isotope which can serve as a basis for all others. Reaction and structure physics codes can then generate data used by Monte Carlo and deterministic meshing codes based on the experimental data that characterizes this nucleus. Further experimental validation and peer evaluation will ensure that this data is consistent with ongoing research. To contribute to this progress, my PhD thesis consists of building a complete level scheme up to the neutron separation energy, assigning spin and parity to nuclear states, and calculating the radiative strength function of the Fe-56 nucleus. Fe-56(p,p'g) data was successfully collected at Argonne National Lab's ATLAS accelerator employing the gamma tracking array GRETINA developed by LBNL and charged-particle detection array Phoswich Wall developed by Washington University. Measurements of the scattered proton's angle and energy as well as the complete Compton trajectories of the emitted gamma rays give a complete description of the nuclear reaction to unmatched accuracy and statistics. The data already reveals hints of a previously unmeasured quantity in nuclear physics. Alignment can be experimentally seen from the angular resolution of GRETINA by observing the gamma ray intensity map. Further characterization of the width of this alignment will inform the nuclear physics community as to how a well a beam of particles orients target nuclei in a specific direction.


1. Nuclear Level Densities and Gamma-Strength with Quasi-Continuum Lifetimes
L. E. Kirsch, L.A. Bernstein, A.O. Macchiavelli, D.G. Sarantites, H.L. Crawford, M.D. Jones, M. Cromaz, P. Fallon, C.M. Campbell
UC Berkeley Thesis, To be completed December 2017

2. Gamma-Strength from Quasi-Continuum Lifetimes
L. E. Kirsch, L.A. Bernstein, A.O. Macchiavelli, D.G. Sarantites, H.L. Crawford, M.D. Jones, M. Cromaz, P. Fallon, C.M. Campbell
Phys. Rev. Lett., To be submitted for publication Fall 2017

3. RAINIER: A Simulation Tool for Distributions of Excited Nuclear States and Cascade Fluctuations
L. E. Kirsch, L.A. Bernstein
Nucl. Inst. and Meth. A, Submitted for publication Sept. 2017

4. A new measurement of the 6Li(n,a)t cross section at MeV energies using a 252Cf fission chamber and 6Li scintillators
L.E. Kirsch, M. Devlin, S.M. Mosby, J.A. Gomez
Nuclear Inst. and Methods in Physics Research, A 874C (2017) pp. 57-65

5. Beam-induced Back-streaming Electron Suppression Analysis for an Accelerator Type Neutron Generator Designed for 40Ar / 39Ar Geochronology
C. Waltz, M. Ayllon, T. Becker, L. Bernstein, K. Leung, L. Kirsch, P. Renne, K. van Bibber
Applied Radiation and Isotopes, 125 (2017) 124-128

6. Magnetic moment and lifetime measurements of Coulomb-excited states in 106Cd
N. Benczer-Koller, G. J. Kumbartzki, K.-H. Speidel, D. A. Torres, S. J. Q. Robinson, Y. Y. Sharon, J. M. Allmond, P. Fallon, I. Abramovic, L. A. Bernstein, J. E. Bevins, H. L. Crawford, Z. E. Guevara, A. M. Hurst, L. Kirsch, T. A. Laplace, A. Lo, E. F. Matthews, I. Mayers, L. W. Phair, F. Ramirez, and A. Wiens
Phys. Rev. C94, 034303 (2016)

7. Z = 50 core stability in 110Sn from magnetic-moment and lifetime measurements
G. J. Kumbartzki, N. Benczer-Koller, K.-H. Speidel, D. A. Torres, J. M. Allmond, P. Fallon, I. Abramovic, L. A. Bernstein, J. E. Bevins, H. L. Crawford, Z. E. Guevara, G. G ̈urdal, A. M. Hurst, L. Kirsch, T. A. Laplace, A. Lo, E. F. Matthews, I. Mayers, L. W. Phair, F. Ramirez, S. J. Q. Robinson, Y. Y. Sharon, and A. Wiens
Phys. Rev. C93, 044316 (2016)

8. Seebeck coefficient measurements on Li, Sn, Ta, Mo, and W
P. Fiflis, L. Kirsch, D. Andruczyk, D. Curreli, D.N. Ruzic
Journal of Nuclear Materials 438 (2013) 224-227

9. 3-D Virtual Reality for Education, Training and Improved Human Performance in Nuclear Applications
C. Xi, H. Wu, A. Joher, L. Kirsch, C. Luo, M. Khasawneh, R. Uddin
ANS NPIC HMIT 2009 Topical Meeting


Nuclear Science and Security Consortium Fellowship Recipient
The NSSC's mission is to support the nation's nuclear security agenda, recruiting and training students in relevant nuclear disciplines in preparation for research and leadership roles in the national laboratories. The NSSC draws students and scholars together in unconventional ways, replacing the boundaries that separate disciplines with a more inclusive science-technology policy interface.

2013 Recipient of the Lisle Abbott Rose Scholarship
In 1957 Friends of Lisle Abbott Rose, former director of public information for the College of Engineering, established a fund in his memory from which an award is made annually to recognize an outstanding senior student in engineering. In 1994, Mrs. Mildred Maddux Rose, his widow, endowed the award in perpetuity. It is awarded annually to a student who most nearly approaches the ideal of technical excellence combined with cultural breadth, depth, and sensitivity. The recipient is given an individual plaque and his/her name is placed on the permanent memorial in Engineering Hall.

ANS Robert G. Lacy Memorial Scholarship 2012 (Presented to undergraduate students of nuclear science and engineering in recognition of outstanding efforts and academic achievements in pursuit of a college education.) Received at the 2012 ANS Annual Meeting "Nuclear Science and Technology: Managing the Global Impact of Economic and Natural Events" Chicago, IL 2012

ANS Undergraduate Scholarship 2011 (students who have completed courses of study leading to a degree in nuclear science, nuclear engineering, or a nuclear-related field)

UIUC George H. Miley LENR Undergraduate Scholarship 2012 (presented to a highly motivated continuing undergraduate student in the department of Nuclear Engineering)

Nuclear Regulatory Commission Scholarship 2009-2011 (provides funding to support for nuclear science, engineering, technology, and related disciplines to develop a workforce capable of supporting the design, construction, operation, and regulation of nuclear facilities and the safe handling of nuclear materials)

Nuclear Energy University Programs Scholarship 2010 (attract high-quality undergraduate students into Nuclear Science and Engineering (NS&E) disciplines and to help train and educate the next generation of nuclear scientists and engineers)

Exelon Corporation Nuclear Power Engineering Education Program Scholarship 2009-2011 (promoting the study of science, engineering and technical skills, we contribute to our future energy leadership)

UIUC Travel Fellowship Abroad 2011 (An alumnus of the College of Engineering, Armin Elmendorf, established a fund to encourage engineering students to seek an understanding of the responsibilities of world citizenship)

I4I Study Abroad Scholarship 2011 (scholarship dedicated specifically for the students to help off-set expenses to any type of study abroad program)

UIUC Cornwell, R.E. Memorial Scholarship 2009