This category provides an overview of BSF. Each of the core novel technologies it depends on is listed as a sub-category. These technologies must be shown to work reliably. If you post here about a technology issue that hasn’t been addressed, a moderator will (hopefully) create a new, permanent sub-category to house it.
Sphere (a.k.a. blast chamber or reactor vessel)
This needs to be huge—not some tinker-toy setup. Here’s why:
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To maximize the tritium breeding ratio and protect the chamber wall from neutron damage and x-ray erosion, a large blanket is desirable. For example, a radial thickness of approximately 2.15 meters of Yb:FliBe is required to capture 99.99% of the neutrons.
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Yields from ICF targets increase super-linearly with the amount of driver energy. Ideally, to maximize gain, the reactor should operate at the highest yield it can tolerate, even if that means a lower repetition rate. For instance, Sandia National Laboratories proposed 20 GJ targets in their 2005 annual report for a cylindrical Z-IFE chamber (6 m radius, 8 m height) running at 0.1 Hz to produce 2000 MW. Their reasoning: “The economics of scale will favor having a single chamber with the largest acceptable yield.” A lower repetition rate also simplifies pumping the hot blanket material between pulses.
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A more massive target requires more ignition energy, so the total laser medium must scale accordingly. NIF uses 11.8 m³ of Nd:glass to produce 4 MJ of laser light. BSF targets are larger (~20 mg vs. NIF’s ~0.24 mg), so they require ~20 MJ for ignition. Assuming Yb:FliBe can match Nd:glass in energy density, my reactor would need ~60 m³ (a sphere with ~2.4 m radius) of Yb:FliBe.
Targets
The ~20 mg of DT gas fuel (equivalent to 6.8 GJ at 100% burn-up) is injected and transported via the circulating coolant—molten Yb:FliBe. Initially, the gas pocket is irregularly shaped, but to minimize surface area and conserve energy, it quickly becomes spherical. This is facilitated by FliBe’s high surface tension—three to four times that of water—due to its strong ionic cohesion.
Inlet/Outlet
The sphere has two 1-meter diameter holes: one at the bottom and one at the top. Coolant flows through large, cone-shaped funnels. A gaseous bubble of fuel is injected into the cold coolant entering the bottom funnel. As the funnel narrows, the bubble accelerates upward until it reaches the opening into the sphere. After fusion, the hot coolant exits through the symmetrical funnel at the top.
Sensors
Sensor systems are located at the bases of the inlet and outlet cones, consisting of optical fiber arrays. These cone-shaped funnels widen radially and serve not only as conduits for coolant but also as structural supports for the sphere. Their thick metal walls—battleship armor thick—extend over a meter outside the sphere before making a sharp 90-degree turn to form spherical end-caps.
Coolant enters and exits tangentially from the sides of these protrusions. The end-caps are reflective, reducing radiant heat loss from the fuel, and they are studded with optical fibers to emit and detect light pulses, functioning as optical sensors.