Building Micro Black Holes utilising the Ulam Ablation Pressure Principle
In this article I will present one of those unimaginable applications of pure fusion detonations that may occur in the near future. Only a few decades from now on, after the solar system is becoming settled and the first interstellar arks are on their way to extrasolar earthlike planets, mankind may begin to start looking for new challenging goals. They may start experimenting with ultradense objects that are able to distort space and time. They may build an artificial black hole to use it as the ultimate power plant. I will show You now a first design for a machine that really creates an artificial black hole. I’ve calculated it, to be sure that it would work. I’m 95% sure but I’m only an engineer and a bad physicist, and want to put it up for discussion with presenting it here. Readers who know my texts know I like experimenting with interesting ideas. So don’t be too exited and afterwards sad if someone proofs that it will not work. There migth be still errors. I call the machine The Shark.
In my last article  I have been wondering about possible civilian applications of nuclear detonations. I have shown that if mankind owned a 100% clean raw fusion bomb it would be possible to build simple fusion power plants in the underground and support cities with extreme cheap electric energy by using controlled civilian thermonuclear detonations to produce extremely cheap and endless power . These powerplants would even become much simpler if built in the shelf ice of Antarctica. But the cheapest of those kind of powerplants would be located below the lunar surface due to the virtually unlimited size of the pressure vessels that can be built there. I’ve presented a solution for that aggravating heat radiator problem in space and on the moon by using bedrock as long time radiator . Giant simple flying platforms, made of concrete and construction steel, propelled by pure fusion detonations, will supply earth with goods from the moon and the asteroids and vice versa, and will make space travel cheaper than seafaring today. Asteroids and comets can be tugged by the means of staggered thermonuclear pulse propulsion. You can read about this and more and see some drawings here .
The ultimate Tool
Imagine a machine that creates massive celestial objects. This is possible with pure fusion energy as power source. But with no other means – this can be calculated. Nature does it with fusion energy, so I will try to reverse engineer a tiny star. I think like a bionic engineer, but the prototype or model I behold is not an animal, it’s a star. So one could name this kind of thinking stellarics or stellorics. The goal is to get the machine as small as possible, with other tricks than pure rest mass, like the stars do. That’s just for saving material – billions of tons of material. The last decade I thought of going an indirect way to approach the goal, lasers, particle beams, electromagnetic fields. General relativity allows any kind of forces to distort space-time, not only inertial or rest mass. But exactly like the todays attempts to get to fusion energy it was a blind alley. There’s only one way: the straight way without wasting energy in electric converters. Todays common thinking in engineering and physics to do anything electric – it is very convinient and clean in the laboratory – hindered or prevented me to find another (dirty) solution. When I read the first time about the processes of direct ablation implosion I knew immediately that this could be a possible path to artificial black holes.
Actually my machine it’s just a big iron globe of 5 to 500 diameter, in an orbit far behind Neptune. The diameter of the iron globe depends on the desired lifetime of the resulting black hole: with 5 m diameter it will have a lifetime of 100 years, with 500 m it’s lifetime will be much longer than the age of the universe. This can be calculated. The globe is build of simple, raw asteroid iron by means of those flying platforms I’ve mentioned. The Asteroids have been tugged to the building site by means of nuclear pulse propulsion. They have been processed very fast by clean raw nuclear fusion detonations. This is all possible immediately after the invention of pure fusion detonators as I wrote in . In hundred thousand kilometres distance from the globe some hundred spezialized space stations are located spherically around it. Of course they are also built of asteroid materials with nuclear fusion power. These stations contain hundreds of civilian high yield fusion detonators each and a linear accelerator to launch them quickly one after the other with a very short distance from each other and very high speed.
Cascades of very simple nuclear fusion detonators are fired from all directions on the celestial iron object and are triggered synchronized to form a hot plasma sphere with a certain distance to the iron globe. The surface vapourizes fiercely for a fraction of a second. It’s the same principle like it is used in the Teller-Ulam fusion detonators, where the heat of a fission bomb lets the surface of a cylinder – the tamper – vapourize. The massive metal tamper is pushed inwards from the exploding plasma that leaves the tamper surface in all directions. It’s just like a rocket at lift-off, where a very fast gas jet lifts a huge massive object of several thousand tons slowly in the opposite direction. Imagine this gas jet would be 100 times faster than in the rocket and the energy source for the gas would be 10,000 times more powerful than the rocket engine, then You have the Teller-Ulam principle. Today we are able to let implode things to a pressure and density level like the core of a star. It’s our one and only artificial fusion energy source and there seems to be no alternative for a very long time. But the Teller-Ulam principle is capable of doing more than creating temporal miniature stars.
The iron globe is surrounded and thermalyzed not by fission energy but by pure fusion energy. This is cheaper and brings a little more power. It may be beneficial to surround the iron globe with a heavy iron sphere with holes, where the nukes fly in. The iron sphere can reflect part of the X-ray energy back to the inner iron globe. The fusion detonators are triggered just above the surface of the iron globe and the Teller-Ulam principle does it’s work. It pushes the massive, metal object inwards, just for a fraction of a second. A spherical pressure wave runs from the surface to the core and multiplies geometrically.
During the explosion the next more powerful salvo is entering the plasma sphere and is ignited by it’s thermal energy, and the next, and the next, and so on. Hundreds may be enough to excite very high energy levels at a rising pressure slope that let’s the shock waves gradually grow as if it was increased continuously. This delay in pressure increase is neccessary for not blowing up the whole globe in one instant by dissipation heat, but getting out an acceptable fraction of mechanical pressure force. This principle of delaying and damping the pressure shock wave is also used in a comparable microscopic style in our hydrogen bombs.
Only the first salvo of thermonuclear detonators has to be of deuterium with primaries to ignite them. The following salvos don’t need primaries – the last attenuating blasts are their primaries. The following blasts also can be of any fusionable material – not only deuterium.
I will do some calculations to convince myself if the machine can work. First I will derive from Einsteins law of gravitation a simple formula for the 3-dimensional space that accounts for the pressure from outside. The well known Newton gravitation law as a special case of Einsteins law in 3-dimensional space does not account for the pressure, because normally the gravitational pressure of massive objects is negligible . This is not the case, if one pushes a massive object with huge forces from outside.
For example, the sun is not heavy enough to become a neutron star or a black hole at the end of it’s lifetime after it has consumed all it’s fusion fuel and collapses. We don’t have this power, but if some extraterrestrials had a technology to compress it additionally from outside with the appropriate pressure it would of course become a black hole. This can be derived directly from Einsteins law of gravitation and it’s energy-momentum tensor. It shows us that any form of energy becomes part of the gravitational field – not only rest mass energy.
I will derive now a very simple gravitation law similar to Newtons for the 3-dimensional space from Einsteins law that is able to handle the pressure influence.
Ricci-Tensor and it’s non-relativistic Limit
For the non-relativistic limit the energy-momentum tensor is normally calculated in the following way. We start with the definition of the Ricci-Tensor
R_kn = D_n C_jkj – D_j C_jkn + C_pkj C_jpn – C_pkn C_jpj (1)
where C_mnp is the Christoffel Symbol
C_mnp = 0.5 g_mk (Dg_kn/Dx_p + Dg_pk/Dx_n + Dg_np/Dx_k) (2)
D is the partial derivative symbol, x_n is the four dimensional coordinate. In the non-relativistic limit the approximate metric is given by
ds^2 ~= (1 + 2 Phi/c^2) dx_0^2 + g_ab dx_a dx_b (3)
with the gravitational potential Phi, the time coordinate ‚_0‘ and the space coordinates ‚_a‘, ‚_b‘. We see
g_00 ~= (1 + 2 Phi/c^2) (4)
Thus the only non-trivial equation for the Ricci-Tensor is
R_00 = D_0 C_j0j – D_j C_j00 + C_p0j C_jp0 – C_p00 C_jpj ~= – D_a C_a00 (5)
because the first term vanishes due to the static nature of the metric and the last two terms are approx. zero. For a static gravitational field the Cristoffel symbol can be calculated as
C_n00 = -0.5 g_nk Dg_00/Dx_k (6)
and with Dg00/Dx_0 = 0 it is
C_a00 = -0.5 g_ab Dg_00/Dx_b (7)
n,k are the four-dimensional coordinates and a,b the three dimensional coordinates.
(4) in (7) leads to
C_a00 = – 1/c^2 D_a Phi (8)
(8) in (5) let us obtain
R_00 ~= 1/c^2 D_a D_a Phi = 1/c^2 H^2 Phi (9)
where H = D_n is the Hamilton operator in three-dimensional Euclidean metric space.
The general and total energy-momentum tensor T_kn in general relativity for a perfect fluid is
T_kn = (p + rho c^2) U_k U_n – g_kn p (10)
where k and n are the indices, p is the pressure rho is the mass density, U_n is the four-velocity vector and g_nm is the metric of the space-time. The non-relativistic case mostly with negligible gravitation pressure p << rho c^2, g_00 ~= 1 becomes
T_00 ~= rho c^2, T ~= rho c^2 (11)
In most practical calculations this is sufficient and the contribution from the pressure can be neglected. But not in our case, where we want to squeeze an object into infinity with ablation pressure
T_00 ~= rho c^2, T ~= p g_kn U_k U_n – g_kn g_kn p = rho c^2 – 3p (12)
Einsteins General Law of Gravitation
The gravitational law can be written with contracted energy-momentum tensor
R_kn = – (8 pi G / c^4) (T_kn – 0.5 g_kn T) (13)
or with a contracted Ricci-Tensor Rkn, the Ricci-Scalar R
G_kn = R_kn – 0.5 g_kn R = – (8 pi G / c^4) T_kn (14)
Here G = 6.67e-11 Nm2/kg2 is the universal gravitation constant. G_kn is called the Einstein-Tensor.
Newtons Special Case Law of Gravitation
From (13), (11), (9), and g_00 ~= 1, with k=n=0 we obtain
T_00 – 0.5 g_00 T = rho c^2 – 0.5 rho c^2 = 0.5 rho c^2 (15)
R_00 = 1/c^2 H^2 Phi = – (8 pi G / c^4) 0.5 rho c^2 (16)
H^2 Phi = – 4 pi G rho (17)
The solution of this differential equation is
Phi(r) = – G V-Int( rho dV/r) (18)
Proof by inserting:
Phi(r) = – G V-Int( rho dV/r) = – G Int( rho A(r) dr /r)
D/Dr(Phi) = – G rho A(r) /r = – G rho 4 pi r^2 /r = -G rho 4 pi r
D/Dr(D/Dr(Phi)) = – 4 pi G rho
Integrating (18) with uniform mass distribution over the volume results in
Phi = – GM/r (19)
which is Newton’s law of gravitation. With
F = m g = – m Grad(Phi) (20)
F = m g = G m M / r^2 (21)
Special Case Law of Gravitation for a Gravitation Press (Sharks Law)
From (13), (12), (9), and g_00 ~= 1, with k=n=0 we obtain
T_00 – 0.5 g_00 T = rho c^2 – 0.5 rho c^2 + 1.5 p (22)
R_00 = 1/c^2 H^2 Phi = – (8 pi G / c^4) (0.5 rho c^2 + 1.5 p) (23)
H^2 Phi = – 4 pi G rho (1 + 3 p / (rho c^2)) (24)
The solution of this differential equation is
Phi(r) = – G V-Int( rho dV/r) – 3 p G/c^2 V-Int(dV/r) (25)
We can proof this again by inserting and see that it is a solution of the differential equation.
Integrating (25) with constant density within the volume results in
Phi = – GM/r – 3 p G V/(r c^2) (26)
F = m g = – m Grad(Phi) (27)
F = m g = G m M / r^2 + 3 p G m V/(r^2 c^2) (28)
This gravitation law for domestic use in 3-dimensional space is quite amusing. It means for example if you had two asteroids that are attracting each other by gravity, their gravity force would increase, if you could compress them. For example if they would orbit each other around a common center of mass let’s say in one hour and you would now squeeze one of them with a certain (huge) pressure, the center of gravity of both would move slightly to the compressed asteroid and both would orbit faster, let’s say in 50 minutes. Interesting, isn’t it?
To form a miniature black hole, the surrounding matter must be compressed to such high densities that it’s circumference is smaller than the event horizon, also known as Schwarzschild radius. The Schwarzschild radius is the point where the escape velocity equals the speed of light. The escape velocity for a body is in the Newtonian field
E_kin + E_pot = 0 (29)
0.5 m v_esc^2 – GMm/r = 0
v_esc = sqrt(2GM/r) (30)
The escape velocity in the Gravitation Press or Shark field is
E_kin + E_pot = 0
0.5 m v_esc^2 – GMm/r – 3 p G V m/(r c^2) = 0 (31)
v_esc = sqrt(2GM/r + 6pGV/(r c^2)) (32)
G = 6.67e-11 Nm2/kg2 is the universal gravitation constant. M is the mass of a spherical body and r is the radius from the center of the body, p is the pressure, V is the volume of the body rho is the density of the body. To find the Schwarzschild radius one has simply to replace v_esc with the speed of light:
r_sch = 2GM/c^2 (33)
r_sch = 2GM/c^2 + 6pGV/c^4 (34)
(33) is well known (34) is a variant that is appropriate for our problem.
Lowest Energy Limit
The volume of an iron globe of 250 m radius would be
V = r^3 * pi * 4/3 = 65e6 m3 (35)
With the density of iron 7.8 g/cm3 it is 5e11 kg. Using Einstein’s rest mass energy equivalence formula
the mass or 5e11 kg of the 500 m diameter iron globe is equivalet to an energy of 4.5e28 J. I assume that to squeeze the mass of a body to an infinitely small point at least the same energy the mass is equivalent to (36) is needed. If we provide fusion energy to squeeze a 250 m radius iron globe we need at least
m = E/0.003c^2 = 4.5e28 J /0.003c^2 = 1.2e14 kg (37)
fusion fuel, i.e. deuterium, for such a prozess. This is because 0.003 of the fraction of mass is converted to energy at nuclear fusion. Or we can also say: for any kg black hole we need at least 1/0.003 kg = 333 kg deuterium fuel to squeeze it to infinity.
For a 250m radius iron globe this would be a correspondend liquid deuterium sphere with deuterium density of 70 kg/m3 of 8300 m radius and 1.2e14 kg mass. But as I said, after the first wave of detonations any other material that is able to produce fusion energy can be uses. Because only a maximum of 0.3 % of the plasma is converted into energy, there is 0.997 * 1.2e14 kg of additional plasma mass.
Event horizon without pressure
The iron globe weighs 5e11 kg. This gives with G = 6.67e-11 Nm2/kg2 and
r_sch = 2GM/c^2 = 7.5e-16 m
or 0.75 fm (femtometer) for the Schwarzschild radius. 1.5 fm diameter is the size of a single proton. For example using the mass of the Sun as 2e30 kilograms, gives theoretically 2964 meters for the Schwarzschild radius of a solar mass black hole. But our sun can never become a black hole, it is too small for that.
The density for transforming a 250 m radius iron globe of 65e6 m3 into a black hole of the diameter of 1 neutron, 1.5 fm, with 1.8e-45 m3 volume is 5e11 kg / 1.8e-45 m3 = 2.8e56 kg/m3 = 2.8e53 g/cm3. For the sun with 2e30 kg and 2964 m Schwarzschild radius it would be 1.8e19 kg/m3 = 1.8e16 g/cm3.
The plasma creates a sphere around the globe and the plasma is faster (has more kinetic energy) than the vapourizing plasma from the surface of the sphere, so I assume that half of the plasma of 1.2e14 kg is becoming part of the mass of the massive object, that is 6e13 kg. The new event horizon is then
r_sch = 2GM/c^2 = 9e-14 m
It is at least bigger than an atom now. The density for transforming 6.05e13 kg into a black hole of the diameter of 9e-14 m with 3e-39 m3 volume is 6.05e13 kg / 3e-39 m3 = 2e52 kg/m3 = 2e49 g/cm3.
Event horizon with pressure
After all detonators are fired the object has a mass of 6.05e13 kg, it has started to implode but due to the additional mass from all detonations I assume that the Volume is still the same at this time. It should be possible to calculate a fast detonation rate that let’s the radius and volume be constant for a short time. The maximum pressure that fusion detonations can provide can be calculated as follows. The ablation pressure on a Teller-Ulam tamper in a hohlraum is typically
P = m_evap_rate * v_ex
and because both, the mass evaporation rate and the plasma expansion velocity, are only functions of temperature, it is possible to reduce the ablation pressure formula for a tamper in a hohlraum to
P = 0.3 E[eV]^3.5 [bar]
E ist the energy in eV. For fusion reactions we have typical energy outputs of 4.8MeV. That means with fusion it would be possible to achieve this energy in a hohlraum, if the hohlraum is very small. An alternative to a small hohlraum is to increase the number of energy sources. With 4.8MeV we get
P = 0.3 * 4.8e6^3.5 = 7.3e22 bar
or 7.3e27 Pa. We can use this value for calculating the Schwarzschild radius
r_sch = 2GM/c^2 + 6pGV/c^4 = 9e-14 m + 2.3e-8 m (!) = 2.3e-8 m
This means the radius of the event horizon is 260,000 times bigger than without that tremendous pressure from outside. The density for transforming 6.05e13 kg into a black hole of the diameter of 2.3e-8 m with 5.1e-23 m3 volume is then ‚only‘ 6.05e13 kg / 5.1e-23 m3 = 1.2e36 kg/m3 = 1.2e33 g/cm3.
First Phase – White Dwarf
The atom mass of iron is 55.8 u * 1.66e-24 g/u = 9.26e-23 g. The density for a typical white dwarf is 1e9 kg/m3 = 1e6 g/cm3. This means for iron 1.1e28 atoms would be squeezed into one cm3. Approximately half of the atom’s fermions are protons. The electron density would be therefor n = 3e29 electrons/cm3. The Fermi pressure in bar inside the white dwarf would become theoretically
P_fermi = 2.34e-33 * n^(5/3) = 3.2e16 bar (38)
The Fermi energy in eV inside the dwarf would become
E_fermi = 3.65e-15 n^(2/3) = 164 keV (39)
And the Fermi temperature within the artificial dwarf star
T_fermi = E_fermi/k = E_fermi/8.62e-5 = 2e9 K (40)
or 2 billion degrees Celsius/Kelvin/Fahrenheit with the Boltzman constant k = 8.62e-5 eV/K.
Due to the mass of the globe of 6.05e13 kg the volume of the white dwarf star that is created from that mass will be 60,500 m3 and the radius 29 m. The geometrical amplification factor is (250/29)^3 = 640. If the pressure on the surface of the globe was 7.3e22 bar it is 4.7e25 bar on the surface of the white dwarf. That is more than enough to let it implode further.
Second Phase – Neutron Star
The atom mass of iron is 55.8 u * 1.66e-24 g/u = 9.26e-23 g. The density for a typical neutron star is 1e18 kg/m3 = 1e15 g/cm3. This means for iron, after all protons have been transformed to neutrons, 1.1e37 neutrons would be squeezed into one cm3. The neutron density would be therefor n = 1.1e37 neutrons/cm3. The Fermi pressure in bar inside the white dwarf would become theoretically
P_fermi = 2.34e-33 * n^(5/3) = 1.3e29 bar
The Fermi energy in eV inside the dwarf would become
E_fermi = 3.65e-15 n^(2/3) = 1.8e10 eV
And the Fermi temperature within the artificial dwarf star
T_fermi = E_fermi/k = E_fermi/8.62e-5 = 2e14 K
or 200 trillion degrees Celsius/Kelvin/Fahrenheit with the Boltzman constant k = 8.62e-5 eV/K.
Due to the mass of the globe of 6.05e13 kg the volume of the neutron star that is created from that mass will be 6.05e-5 m3 and the radius 29 mm. The geometrical amplification factor is (250/0.029)^3 = 6.4e11. If the pressure on the surface of the globe was 7.3e22 bar it is 4.7e34 bar on the surface of the neutron star. That is more than enough to let it implode further.
Third Phase – Black Hole
For the density of the black hole of 1.2e36 kg/m3 = 1.2e33 g/cm3 the relativistic energy density is 1.1e53 J/m3 and therefor the pressure 1.1e53 Nm/m2 = 1.1e48 bar.
Which geometrical amplification factor do we need to reach the pressure that is needed for the formation of the black hole?
1.1e48 bar/ 7.3e22 bar = 1.5e25
That means the radius of the region that has a sufficient density for a formation to a black hole is
r = 250 m / (1.5e25)^1/3 = 1e-6 m
That is a 44 times bigger radius than the Schwarzschild radius of 2.3e-8 m. This means the formation of the black hole would work. One could reduce the theoretical maximum pressure on the surface of the globe of 7.3e22 bar to a lower technically more feasible level .
The popular author and physicist published 1972 a theory that black holes emmit radiation and therefor loose some mass due to quantum effects. A formula for the evaporation time exists, it is the time until all mass of a black hole has evaporated due to this effect:
t_ev = 5120 * pi * G^2 * M^3 / h * c = 8.4e-17 * M^3 [s/kg3]
where h is the Planck constant. A black hole with the mass of the sun, 2e30 kg, with an event horizon of 2964 m would therefor evaporate 6.7e74 sec or in 2e67 years, much longer than the universe existst. For a black hole of a 500 m diameter iron globe with the additional bomb mass of together 6.05e13 kg is is ‚only‘ 2e25 seconds or still much longer than the universe exists.
Let’s assume our machine may build black holes that exist at least as long as the universe, it is with the standard theory 13.73e9 years or 4.3e17 s, then the minimum mass of our black holes the Shark should build are
M = (1.2e16 * t_ev)^1/3 = (1.2e16 * 4.3e17)^1/3 = 1.7e11 kg
If we allow only 100 years – that should be enough for an economic power plant – or 31.5e6 s then the minimum mass of the black hole is 72e6 kg or an iron globe of 4.6 m diameter and 432 metric tons weight on which a mass of 143,136 tons had been fired and half of it became additional mass. Because the flying platforms I mentioned, that are propelled by pure fusion pulse detonations, will have a payload of 200,000 metric tons such a machine will be of no problem at all after the advent of civilian pure fusion detonations. Even if the material that is needed for the bomb cylinders, space stations and space harbour, is several times heavyer.
Schwarzschild Space-Time Distortion
The Schwarzschild space-time metric for a centrally spherical symmetric massive object is given by
ds^2 = (1 – r_sch/r) c^2 dt^2 – (1 – r_sch/r)^-1 dr^2 – r^2 (dtheta^2 + sin^2theta dphi^2)
If we compare it with the flat pseudo-Euclidean space-time metric
ds^2 = c^2 dt^2 – dR^2 – R^2 (dtheta^2 + sin^2theta dphi^2)
we see that in the flat space-time metric the radial coordinate is the direct measure of the radial distance from the origin of the coordinates. This is not the case for the Scharzschild metric for a black hole. If we compare the second term of the metrics
dR^2 = (1 – r_sch/r)^-1 dr^2
and integrate dR we get
R_12 = Int_r1r2( (1 – r_sch/r)^-1/2 ) dr) = [ sqrt( r (r-r_schw) ) + r_sch ln( sqrt(r) + sqrt(r-r_sch) ) ]_r1r2 > R2 – R1
The last inequality is crucial. It means that only for a small r_sch/r or a big r the distance between points in a flat space and distorted space are equal. If r approaches r_sch the distance in the distorted space becomes bigger. That means when looking to the spot of the black hole from outside, the width and height of the space are the same as in flat space, but the length becomes allways longer when approaching the event horizon. It also means the volume of a sphere that is approaching the event horizon or Schwartzschild radius becomes bigger than in the 3-dimensional flat space.
Would that mean that the volume of the small neutron star increases and the pressure to let it implode becomes lesser with 1/V as (36) shows us:
p = (c^2 / 3V) (c^2r_sch/2G – M)
In principle yes, but the volume increase will be very small because the neutron star is still very big in relation to it’s Schwarzschild radius that the effect is negligible.
Observations and Energy Release
Scientists of the Sapienza Universita di Roma have released a paper  last month where they claim to have observed the formation of a black hole and have discussed alternative attempts to explain. It seems that the theory of an implosion from a neutron star to a black hole after the fermi pressure of the neutrons had been overcome is correct. They have measured that indirectly by an extreme gamma ray burst that can only have it’s origin from a big fraction of rest mass that had been converted to energy. So it seems, that we have to face a big fraction or E = mc^2 that is radiated as gamma ray. So the formation of an artificial black hole should be done with the appropriate distance, maybe outside our planet system.
Does this machine work? I think yes, because of the following reasons:
- damping and accumulating of energy density can be planned and controlled by the staggered salvos of detonators
- geometrical mechanical amplification works if the shock pressure slope is sufficiently damped
- thermal explosion can be prohibited if the shock pressure slope is sufficiently damped
- with very fast computers it is possible to control the calibration of the detonation distance from the object during incoming flight of the bombs and therefor to achieve an exact central pressure point 
- only the first salvo of fusion bombs has to use deuterium, the following salvos can use any fusionable material, as long the energy output is high enough
- only the first salvo needs primaries and a complicated yield staging structure, the following detonators are heated up and compressed by the thermal energy of the predecessors; they will just be a kind of big metal cylinders with fusionable material inside
- black holes that exist at least 100 years have only a weight of 72e6 kg or 72,000 tons and the machine core must only be of 4.6 m diameter (plus the bombs and the surrounding space stations) to produce such a black hole
Is it buildable? I also think yes. Not today but in a few decades and only if:
- we invent pure fusion energy detonators and start using them immediately as universal engineering tools that will give us virtually unlimited possibilities 
- we build pulsed fusion power plants from fusion detonators to provide the cheapest electric energy ever, this will result in an extreme growth of worlds prosperity and will provide us with the economic conditions for building ultimate machines like interstellar arks  and those Sharks, I have just explained
- we build nuclear pulse driven platforms as big as ships and as cheap as ships; these platforms made of reinforced concrete and construction steel are robust and simple on one hand but the fastest space vessels ever on the other hand, both because of fusion power 
- we mine asteroids and comets using pure fusion power; the asteroids are tugged with fusion detonations pulses to change their celestial trajectories to wherever they are needed, e.g. at the Shark building sites 
Why building Sharks?
What is this machine for? Is it a weapon? Is it a reactor? It might be I have just topped a million times the so called doomsday bomb  of the project Orion , that was planned to fit into an Orion space ship and that would be able to irradiate half of a planet by neutron emission, simply all people – even those in bunkers – that are not sheltered by the mass of the planet between them and the bomb. If one would fill the iron globe of the Shark with a huge amount of deuterium he might have built a doomsday bomb of stellar size. The resulting titanic neutron bomb may have sufficient fire power to impede and irradiate any kind of alien heavy armored fleet approaching our solar system if they prove as conquerors and not as friends.
In such a scenario the Shark would be similar to the neutron bombs  in the cold war against the tank superiority of the Warsaw Pact  armored ground forces and it could similarly guarantee freedom, because invasion becomes self-destruction. Maybe I have invented an alternative to Arthur Clarke’s ‚3001‘  computer viruses against alien invasion – the only realistic defence I had heard to this day. Massive neutron radiation of an artificial supernova will certainly stop them. Just for the case roving enemies from afar don’t use variants of our digital computers. One could first try a shot accross the bows with the formation of two or three micro black holes with only a short time distance between them. The extreme gamma ray burst they emmit would be detectable over long distances. Two or three shortly after each other can only occur from intelligent lifeforms and they are too small as to be from stellar sources. If the fleet is only a pirate fleet they will probably activate their engines soon and change trajectory. This show of force would be no wastage, we could use the new black holes as powerplants after.
But military application is not what it is meant for. It’s just a side-effect. Devices with huge power that can do very bad things can also do amazing good things. It is the same with knifes, axes, motorcars, nuclear reactors, airplanes, carrier rockets. And it is the same with our hydrogen bombs that can bring us unlimited prosperity  and it will also be the same with the Shark device.
The Shark can create black holes. A black hole power plant (BHPP) is the ultimate power plant. After a tiny black hole is created, we can feed it with any kind of matter, with junk or dirt and it will provide us with a huge fraction of the equivalent mass energy of the matter. About 30% maximum of the matter equivalence energy E = m c^2 can be harvested . With fusion it is only 0.6% maximum with fission only 0.1%. So my fusion energy power plants built around fusion detonators, if Nomads  or Antartica Versions  or Standard Types  and even the newest version are actually only a small but inevitably step to the BHPP’s.
Just kick a football or whatever into the near of the black hole, it will crush it and soak it up, then it emmits beams of pure matter energy from it’s poles. These beams can be used to heat steam and propell turbines and generators. The electric energy can be transfered by microwave to all corners of the solar system. No special chemicals like deuterium, tritium or uranium is needed. The kind of matter doesn’t matter – anything is fuel. One tennis ball or old sports shoe or even one old Pampers thrown into the black hole will provide the complete electric energy needs of a big city on earth for more than one year. Calculate it with (36), if You don’t believe it.
It may be possible to create a kind of civilian miniature supernova with the Shark, letting it fuse all higher elements that a todays Teller-Ulam device can’t do. The thermonuclear bomb can only fuse deuterium, but the imploding Shark can fuse any kind of matter, even if it’s actually an energy sink. This could be of great benefit if some day in the future some exotic elements are becoming sparse. We could breed some tenthousand tons of them from more common elements (and dirt) with that ultimate machine. The alchemists dream of producing gold might become reality – in a very big scale. There will be no sparseness of any element anymore. Far behind the Kuiper belt the distance of such machines to the planets would be big enough for not irradiating them during operation, they could constitute simultaneously the defence shield I mentioned before.
But actually I designed the Shark for studying the effects of space and time practically. After a black hole is created it can be feed further and grow. Maybe to a giant size of a micrometer or even bigger. For a black hole this is huge and it would mean to feed it with thousands of asteroids. The black hole neighboorhood (far beyond Neptune, of course) would then become a perfect laboratory for studying space and time or even build new machines out of artificial black holes. Now it’s Your turn to think about new black hole applications, dear reader. Start thinking about black holes like building bricks.
In my opinion mankind of today is in a comparable situation as this ancient guy was:
The caveman sits in a winter night in his cave at a campfire. The cave is full of wood charcoal smell. It is dark. Only the shaddows of his resting tribe members that are with him are dancing on the walls. The walls are full of colorful paintings of the holy mammut hunts of the ancestors. He is looking on the recently invented tomahawk in his hands, that has still some dried blood on it’s blade from the last attack. Last week he attacked another tribe together with some men of his clan to fight for sparse hunting grounds. They were five when they left, they were only three when they returned. The tribe misses their helping hands. Tonight he wonders for the first time what else but to smash enemy skulls can he do with that thing in his hand? He will soon find out how to quickly build cabins, wooden bridges and canoes with that powerful universal tool in his hands – mankinds future: the stone axe.
I don’t know if that monstrous ultimate machine I call The Shark will become a useful device or if it is just one of the swevens and nighmares of another caveman. But I’m convinced there will be thousands of practical applications we will build from our most powerful weapons of today. We will soon find out pure fusion is the powerful universal tool for one goal: to settle the stars.
References and Notes
 Why Mankind must nor fear the Pure Fusion Bomb: https://monstermaschine.wordpress.com/2012/09/25/why-mankind-needs-the-pure-fusion-bomb/#more-2726
 The Fusion Steam Machine: https://monstermaschine.wordpress.com/2012/09/17/the-fusion-steam-machine/#more-2758
 The Nomad fusion reactor: https://monstermaschine.wordpress.com/2012/07/23/a-revised-version-of-the-fusion-steam-machine/
 M. Dalarsson, N. Dalarsson; Tensors, Relativity and Cosmology: http://www.amazon.com/Tensors-Relativity-Cosmology-Mirjana-Dalarsson/dp/012200681X/ref=sr_1_sc_1?ie=UTF8&qid=1349522243&sr=8-1-spell&keywords=tensors+relativity+dallarson
 T. Fliessbach; Allgemeine Relativitaetstheorie: http://www.amazon.de/Allgemeine-Relativit%C3%A4tstheorie-Torsten-Flie%C3%9Fbach/dp/382741685X
 A short discussion about the pressure as a source of the gravitational field: http://physics.stackexchange.com/questions/3688/why-does-pressure-act-as-a-source-for-the-gravitational-field
 I’m not sure if that means the accuracy of the concentration of the pressure forces from outside would further increase with decreasing pressure. I’m not deep enough in quantum mechanics to be able to say, if – and if yes how – the circumference of the neutron star or the white dwarf determine the accuracy of the detonation triggerings. I know, as long quantum mechanics does not account for the implosion the force concentration of the pressure forces is simple geometry, but I don’t know what happens, if the globe becomes a quantum mechanics object. Is there still a concentration, is there still a pressure gradient? It would be very convenient if not. The control of the center of the pressure forces would become much easier.
 The accuracy requirements are dependend on the quantum mechanics behaviour of the white dwarf and the neutron star as I mentioned .
 Some thoughts about black hole power plants (BHPP): http://physics.stackexchange.com/questions/20813/how-would-a-black-hole-power-plant-work
 Hypothetical doomsday bomb or Doomsday device: http://en.wikipedia.org/wiki/Doomsday_device
 Project Orion: http://en.wikipedia.org/wiki/Project_Orion_%28nuclear_propulsion%29
 Neutron bomb: http://en.wikipedia.org/wiki/Neutron_bomb
 Warsaw Pact: http://en.wikipedia.org/wiki/Warsaw_Pact
 Red Army: http://en.wikipedia.org/wiki/Red_Army
 Arthur C. Clarke: http://en.wikipedia.org/wiki/Arthur_C._Clarke
 The First Example of a Neutron Star Gravitational Collapse to a Black Hole: http://arxiv.org/abs/1206.2887