In the relentless pursuit of harnessing the power of the sun here on Earth, scientists have long sought to create compact, efficient neutron sources. Now, a groundbreaking study published in the New Journal of Physics, translated from Chinese as “New Journal of Physics,” offers a novel approach that could revolutionize the energy sector. Led by Z B Wu from Peking University’s Center for Applied Physics and Technology, the research introduces a method for generating high-flux neutron beams using laser-driven collisionless shock acceleration.
Imagine a subpicosecond laser pulse, a burst of light lasting less than a trillionth of a second, interacting with a gas cell target. This target is a simple yet ingenious setup: a uniform deuteron gas enclosed by a thin solid foil. When the laser pulse hits the foil, it heats it up, causing it to expand into the low-density gas. This expansion creates a strong electrostatic field, which in turn accelerates the deuterons to supersonic speeds, launching a collisionless shock wave.
“The beauty of this method lies in its simplicity,” says Wu. “Unlike conventional schemes that require precise control of plasma density profiles, our approach spontaneously generates a strong shock wave, making it a robust and practical solution for neutron generation.”
As the laser pulse penetrates the foil due to relativistic transparency, the shock velocity and the energy of the reflected deuterons are further enhanced. This process results in a high-flux, collimated neutron beam, with a yield per unit solid angle exceeding 10^10 neutrons per steradian. This is six times higher than that from a typical foil target without deuterium gas.
The implications for the energy sector are profound. Neutron sources are crucial for various applications, from medical imaging and cancer treatment to materials science and nuclear energy. A compact, laser-driven neutron source could significantly reduce the size and cost of these technologies, making them more accessible and widespread.
Moreover, this research could pave the way for advancements in laser-driven ion acceleration and intense laser-plasma interactions. As Wu puts it, “This simple approach overcomes the challenges of controlling the density profiles in conventional ablation schemes, paving the way for laser-driven compact neutron sources.”
The study, published in the New Journal of Physics, combines two-dimensional particle-in-cell and three-dimensional Monte Carlo simulations to demonstrate the feasibility of this novel scheme. The results are promising, but the journey is far from over. Future research will focus on optimizing the laser and target parameters to further enhance the neutron yield and explore potential applications.
As we stand on the brink of a new era in neutron generation, one thing is clear: the future of energy is bright, and it’s powered by the power of light. This research is a testament to human ingenuity and our unyielding quest to harness the fundamental forces of nature for the betterment of society. The energy sector is on the cusp of a revolution, and this breakthrough is a significant step forward.