Researchers have made a groundbreaking discovery in the field of fast neutron generation by utilizing few-cycle, relativistic laser pulses. This innovative approach has the potential to revolutionize various applications, from nuclear science and medical research to material science and homeland security. The study, conducted by an international team of researchers, demonstrates the feasibility and effectiveness of this laser-driven neutron source, which can potentially produce an average neutron flux as high as 10 billion per second.
Harnessing the Power of Laser-Driven Neutrons
Conventional neutron sources, such as spallation facilities, have long been the mainstay in the field of nuclear science. However, the emergence of laser-driven neutron sources has presented a promising alternative, offering several advantages over traditional methods.
The key innovation in this study is the use of few-cycle, relativistic laser pulses to generate fast neutrons. By interacting a 12 fs, 21 mJ laser pulse with a thin deuterated polyethylene (dPE) foil, the researchers were able to accelerate deuterons, which then collided with a secondary deuterated polyethylene (dPE) target to produce neutrons through the 2H(d,n)3He fusion reaction.
Experimental Setup and Methodology
The experiment was conducted at the ELI-ALPS facility in Szeged, Hungary, using the SYLOS Experimental Alignment Laser (SEA Laser). The laser pulses were focused onto a dPE foil target, which was mounted on a rotating target wheel and positioned with micrometer precision. This allowed the researchers to take multiple shots on the same target, with the wheel moving to a new position after each burst of 75 shots at a repetition rate of 1 Hz.
To characterize the accelerated ions and the generated neutrons, the researchers employed a range of sophisticated detection systems. Thomson ion spectrometers were used to measure the energy spectra of the accelerated protons and deuterons, while a time-of-flight (ToF) neutron detection system consisting of four plastic scintillators was utilized to analyze the energy and spatial distribution of the neutrons.
Impressive Neutron Yield and Spatial Distribution
The experimental data, which included more than 3,000 laser shots, revealed several remarkable findings. The researchers determined that an average of 1,142 ± 59 neutrons were generated per laser shot, which is an order of magnitude higher than what was previously reported using a kHz laser system with lower pulse energies.
The energy distribution of the forward-directed neutrons peaked between 3 and 3.5 MeV, which is particularly important for various applications. Additionally, the angular dependence analysis showed a perpendicular minimum and a maximum along the deuteron beam, consistent with the expected distribution from the literature and the researchers’ simulation results.
Potential Applications and Future Directions
The development of this laser-driven neutron source has far-reaching implications. The researchers believe that their work can pave the way for the creation of a pulsed neutron source with a Joule-class, kHz repetition rate laser, potentially producing an average neutron flux as high as 10 billion per second.
Such a high-flux neutron source could find applications in a wide range of fields, including:
– physics’>nuclear physics research
– science’>Material science and security’>Homeland security and the Click Here
