Laser fusion experiments
Inertial confinement fusion (ICF) is a process where nuclear fusion reactions are initiated by heating and compressing a fuel target, typically in the form of a pellet that most often contains a mixture of deuterium and tritium. To compress and heat the fuel, energy is delivered to the outer layer of the target using high-energy beams of laser light.* ICF is said to reproduce the energy generation process taking place in the core of the sun.
Several laser fusion projects are underway around the world right now, their main goal is to produce a clean, reliable and nearly unlimited source of energy. All these laser fusion experiments use very high energy lasers of sereval kJ per pulse for which a Gentec-EO calorimeter is the ONLY reliable measuring device available on the market. Over the years, we have been presented with increasingly large and energetic laser pulses to be measured and we have kept pace with the world's most demanding lasers.
*. Source : Wikipedia.
Laser Fusion Mechanism
1. Laser beams or laser-produced X-rays rapidly heat the surface of the fusion target, forming a surrounding plasma envelope.
2. Fuel is compressed by the rocket-like blowoff of the hot surface material.
3. During the final part of the capsule implosion, the fuel core reaches 20 times the density of lead and ignites at 100,000,000 ˚C.
4. Thermonuclear burn spreads rapidly through the compressed fuel, yielding many times the input energy.
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Schematic of the stages of inertial confinement fusion using lasers. The blue arrows represent radiation; orange is blowoff; purple is inwardly transported thermal energy.
Typical pulse values for these lasers are in the range:
| Aperture Sizes: Up to 420 x 420 mm || Energy range: Up to 16 kJ |
| Pulse Widths: Nanoseconds || Wavelengths: From UV to NIR |
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Femtosecond lasers are developping at a very fast pace. Some lasers now feature peak powers in the Petawatts (1015 W). Furthermore, the beam sizes can be fairly small, which results in peak power densities too high for a standard detector. Typically, pulse values for these lasers are in the range:
Beam Sizes: Up to 160 mm Ø
Energy range: 1 J to 100 J
Pulse Widths: Femto & picosecond
Wavelengths: UV to NIR
For these, a Gentec-EO calorimeter is the only reliable solution. Furthermore, it can sometimes be used in power meter mode.