Skip to content
NSF OPAL

Frontier Science

Laser-Driven Nuclear Physics (LDNP)

Summary

Multi-MeV ion beams enable studying the nuclear reaction rates of light nuclei, particularly tritium reactions, with applications to inertial confinement fusion, nucleon-nucleon interactions, and fundamental nuclear structure related to stellar, big-bang, and light-element r-process nucleosynthesis.

LDNP proposed two flagship experiments:

  • Tritium-induced nucleosynthesis (LDNP1):  A controllable, high-yield triton beam is an invaluable tool for nuclear physics in studying the properties of light nuclei. One of the unresolved challenges in Nuclear Astrophysics is how nucleosynthesis proceeds beyond the A=5 gap for nucleosynthesis in core collapse supernovae, big bang nucleosynthesis, and even in neutron star mergers. The mass A=5 gap prohibits the production of substantial amounts of lithium and beryllium.  As an example, tritium-induced reactions on lithium can perhaps explain why the 7Li abundance is three times lower than predicted.
  • Neutron-Neutron Scattering (LDNP2): The neutron-neutron scattering (ann) length is a direct check on charge symmetry and charge independence of the nuclear force.  Presently, this quantity has only been inferred from indirect measurements from breakup reactions with neutral and charged particles on deuterons; no direct measurement of this quantity has been observed.  Knowledge of neutron-neutron scattering length would be of considerable value for nuclear and particle physics community.

The NSF OPAL RI-1 project includes LDNP1 as a flagship experiment and LDNP2 as a future flagship experiment.

Science Mission

 

  • Study exotic nuclear reactions using powerful lasers to understand how elements are formed in the early Universe, which could lead to a better understanding of the Lithium abundance problem.
  • Investigate neutron-neutron elastic scattering which is a direct test on charge symmetry and charge independence for strong interactions between elementary particles.
  • Develop new research tools and diagnostics to study nuclear reactions in a high-electromagnetic-pulses (EMP) environment.

Meet the LDNP Team

Read more about the PIs and meet the Project Team.

Aprahamian_2x3
Ani Aprahamian
Co-Principal Investigator
University of Notre Dame
Chad-Forrest-20230616-jpg
Chad Forrest
Senior Personnel
University of Rochester

FLAGSHIP EXPERIMENT

Laser-Acceleration of Tritons to Study Reactions Between Light Nuclei

Powerful short-pulse laser facilities provide a unique opportunity to study fundamental nuclear physics that is not accessible otherwise. Laser-ion acceleration mechanisms enable the generation of multi-MeV ion beams with miniaturized targets, which is especially attractive for the creation of radioactive triton beams. This technique can be adapted to nuclear science experimentation, and has generated world-wide interest by the basic and applied nuclear science communities.

Tritium-induced reaction allow for di-neutron transfers onto 6Li or 9Be create neutron-rich nuclei that theorists only recently were able to model in ab-initio calculations. In addition, these reactions provide the opportunity to study di-neutron correlations during the transfer. Such light-ion reaction cross sections are also essential for nucleosynthesis models. Example reactions to be studied include 7Li(t, p)9Li, 6Li(t, p)8Li, and 9Be(t, p)11Be which are of high interest for the early r-process and nuclear structure studies.

 

The powerful OMEGA and OMEGA-EP laser systems operating at the University of Rochester (UR), and ultimately NSF OPAL will play an important part in the development of a laser-accelerated triton beam platform with the goal of measuring cross sections of tritium-induced reactions at low energies.

Very few measurements of these reactions have hitherto been made at any energy, even though tritium-induced reactions occur in all DT plasma thermonuclear fusion research, are critical for an understanding of both stellar and big-bang nucleosynthesis, and, as the lightest nucleus with two neutrons, can serve as a testbed for models of nucleon-nucleon interactions and nuclear structure.

Learn More

NSF OPAL Flagship Experiment Selection Report

Read