X-Message-Number: 13722
From: "Yvan Bozzonetti" <>
References: <>
Subject: Power requirement for QND interferometer.
Date: Fri, 12 May 2000 13:28:45 +0200

Power requirement for QND interferometer.

Let assume the photon wave spreads to an area similar to the wavelength or
one nanometer square. To cover a beam section near 10 mm^2, there must be
10^13 photons, each with 1 000 eV energy. This is 10^16 eV or on the order
of one millijoule per pulse.

Because there are 1 000 beams on different frequencies looking at as much
slices in the brain, the full x-ray output of a laser must be near one joule
per pulse. To get that energy, with a laser efficiency of one percent
implies 100 joules pumped at nuclear level. With electronics to nuclear
level coupling near 10 percent, the laser power in the optical range is now
1 kJ per pulse. This beam must be generated by a tunable system, the only
solution is a dye laser, itself pumped by another laser with no more than
one percent efficiency. At that level we are in the 100 kJ range. That
pumping laser may be a chemical laser working with metal vapors. Efficiency
may be near 10 percent here, so the primary energy source must be in the one
mega joule range. To fix some ideas, this may be found in 0.2 lb (~100 g) of
high explosive.

We are not at the end of the road: A QND interferometer must contains up to
2 000 parallel beams. If the energy comes from a shock wave, it may be
difficult to convert more than half the chemical energy to shocked power, so
the final requirement may be 400 kg ( near 1 000 lb) of chemical products
for each pulse. There must be 30 pulses per second and two regenerative
mirror, each as costly as the beam producer, so 100 pulses per second must
be a realistic guess at the primary energy source level.

We then must burn 40 tons of fuel per second to power a brain reader. The
only way to get some shock wave is to produce a supersonic flow in a rocket
nozzle. The powerhouse will then looks as a pulsed motor rocket burning 40 t
of fuel per second. With LOx-CH4 propergols, the thrust would be near 16 000
tons, 8 times the B4400 motor of the Be 2 rocket to be ground tested next
year. The firing of that power station would looks as a tactical nuclear
blast. A man-on-Mars booster would be a toy at this scale. To take into
account over optimistic energy conversion, the true system may well be
scalled up by a factor of two. This would be absorbed for example by the
holographic system where 2 beams are requested to interfere to make the
narrow slice structure of the x-rays wave.

Brain reading is not a faint technology you can do in your garage with some
glasswares. The terrific power station requirement comes from three
constrains:
See at the 100 nm scale.
See in 3 dimensions.
See "in the dark", that is without producing radiation damages on the brain.
I'll look further to potential uses of that kind of technology in other
fields in a forthcomming message.

Yvan Bozzonetti.

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