Glass bubbles, often referred to as “glass bubbles,” are used in various applications, including laser fusion experiments. In laser fusion experiments, these glass bubbles serve as targets or hohlraums, which are essential components for achieving controlled nuclear fusion reactions. Here’s how they are typically used in such experiments:
- Target Spheres: Glass bubbles are filled with a deuterium-tritium (DT) fuel mixture, which are isotopes of hydrogen. The microspheres are carefully manufactured to be of precise size and composition to ensure consistent and controlled fusion reactions. These target spheres are designed to implode when exposed to intense laser energy.
- Hohlraums: In some laser fusion experiments, instead of directly targeting a fuel capsule, researchers use glass bubbles as hohlraums. A hohlraum is a small, hollow container made of a high-Z (high atomic number) material, such as gold or uranium, which surrounds the target fuel capsule. When laser energy is directed into the hohlraum, it creates intense X-ray radiation that ablates the hohlraum wall and drives the compression of the fuel capsule, leading to fusion reactions.
- Precision and Uniformity: The quality of glass bubble is critical in laser fusion experiments. Their size, shape, and composition must be highly uniform to achieve consistent and repeatable results. Deviations in the size or composition of the microspheres can lead to variations in the implosion process, affecting the fusion yield and experimental data.
- Optical Properties: Glass bubble used as laser fusion targets or hohlraums should have specific optical properties to efficiently transmit and absorb laser energy. They should be transparent to the laser wavelength and, in the case of hohlraums, capable of efficiently converting the laser energy into X-ray radiation.
- Precision Fabrication: These glass bubble are manufactured with a high degree of precision using techniques like sol-gel processes or microfabrication methods. These processes ensure that the microspheres meet the required size and composition standards.
