Reply To: NIMBY FUD

[BSFusion]

@Jamesr,

Just to pick 2 points from your list (13 & 14) Laser technology has moved on enormously since NIF was designed – for example, new diode pumped lasers are much more efficient, resulting in less heat needed to be dissipated between shots. They are not quite there yet, but progress is good.

Yes, diode pumped lasers are more efficient than those pumped by flashlamps, I agree. The reason for this is that diodes have a narrow optical bandwidth that allows them to pump directly to certain transitions of laser-active ions without losing power in other spectral regions. In addition, there has also been progress made toward raising the electrical-to-optical efficiency, which is now greater than 80%, and lowering the cost per Watt (see chart below). But, there is another inefficiency, unrelated to the pump frequency mismatch mentioned above, that produces a significant amount of waste heat.

The term quantum defect refers to the fact that the input energy of a pump photon is generally higher than that of the output laser photon. The energy difference goes into heating the laser medium. The quantum defect of a laser can be defined as the part of the energy of the pumping photon which is lost (not turned into photons at the lasing wavelength) in the gain medium upon lasing. At given pump frequency vpump and given lasing frequency vlaser, the quantum defect equals h*vpump – h*vlaser, where h is Planck’s constant and v stands for frequency. For example, if an 808 nm pump is used to produce 1060 nm laser output, then [1-(vlaser/vpump)] = 23.7% of the energy goes into waste heat.

Unfortunately, the quantum defect in ICF turns into low-level waste heat, which costs additional energy to remove, because it has to be actively removed in order to prevent damage to the solid-state gain medium. BSF was designed to avoid this handicap; BSF pumps directly into the hot, circulating, liquid coolant, so the quantum defect can be recovered in subsequent heat cycles. And, because BSF uses a reflective spherical mirror, instead of using transparent lens for its laser optics, there is no danger of optics damage (warping, melting, or fracturing).

I’m sure someone could come up with an equally long list of points regarding your BSF concept. Have you submitted any papers to peer reviewed journal
that cover it? I find the paper format easier to scrutinise than a patent application, since journals insist on being suitably succinct.

Perhaps a list of obstacles facing BSF could be started, but, so far, no potential objections have even been raised. 😉 A peer-reviewed paper might be a good idea too, but what journal would publish it, and who would write it? Not me, I have neither the time nor the skill to undertake a major writing project. So, unless someone wants to volunteer, that idea is DOA.

Attached files