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La bombe atomique |
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La bombe atomique (à la fission) est basée sur le fait que si un
neutron frappe le noyau d'un dernier atome lourd ce fraziona dans deux parts,
dans les plus libres deux électrons qui maintiennent surtout librement à la
réaction en chaîne et à une énorme énergie. Dans l'uranio qu'on le trouve en
nature la cette réaction qu'elle se produit naturellement mais dans elle vient
abstenu du fait que, étant l'uranio pas complètement pur, la réaction ferme
immédiatement et de petits atomes sont seulement transformés dans l'énergie.
Puis ce pour considérer le fait que beaucoup d'électrons réussissent pour
s'échapper du morceau d'uranio (cette réaction de la radioactivité).
Dans la
manifestation de bombe de ce type l'énergie qu'exempt de la fission complète
d'un kilogramme d'uranio est égal à celui-là a produit à partir de la combustion
de 2450 tonnes de charbon.
Quand la masse de notre matériel radioactif sait
qu'assez ils pour assurer un équilibre entre les réactions produites et ceux
échouées dit que la masse est critique, cela est qui peut provoquer une réaction
en chaîne capable pour faire pour éclater l'objet.
Pour la perfection de I
qu'il de la réaction en chaîne de la pièce de neutron est nécessaire que la
masse qui supporte la fission soit rendue critique seulement immédiatement de la
manifestation, cette dernière condition peut être réalisé avec 2 arrange :
. The first system, used also in the bomb used on . Hiroshima était que c'un à l'intérieur divisent la
masse critique dans des parties deux ou plus sous-critiques qu'un cylindre, et
au moment intentionnel jointif au moyen de lui charge normalement avec
l'explosif conventionnel (sopra de foto de c4).(vedi)
Quand le c4 que les
deux éclatent les pièces viennent jointif au grand volocita formant un critique
ou la masse d'ipercritica qui donnent instantanément l'origine à la réaction en
chaîne et donc à la manifestation. Ce système de perfection de I peut être
célibataire utilisé avec uranio235 dans combien le ce dernier fissionarsi d'un
bidon avec des neutrons de n'importe quelle vitesse.
. According to system of I prime is a complicated
P2o more but it allows than to use like material the uranio238 or the plutonio,
this system is used for the bomb on .
Nagasaki . . . According to method it is based on the fact that a
subcritical mass, if strongly compressed, can transform in one critical or
ipercritica mass. . This type of bomb is of spherical shape, in the center of it
is the fissibile material, All around an explosive of chemical type is found
that once primed compresses with one greatest force the subcritical mass,
transforming it in ipercritica and therefore making to explode it. . A method in
order to reduce the mass is to make use of a reflector or commonly said
“tamper”, than it is not other that a layer of a material
that reflects electrons so as to to limit the escapes. . A composed bomb nuclear
from uranio 235 and 238 without reflector is of 48kg of weight, instead, with
the reflector, the mass is lowered until catching up the 21kg. . This system is
called to “implosion”.
. Unit of measure of
the power
. The explosive
power of a bomb nuclear rapportandola measure to how much trito it would be
necessary to make to explode in order to free the same amount of energy. . E' a
measure partially scorretta, because the trito one it, also with the same
explosive power, it does not provoke cancellations, neither radioactive rains,
etc…. . In any case 1 Kiloton = 1,000 tons of trito it. . That is a
bomb from 1 Kiloton has one explosive power equivalent to a heavy device of
1.000 tons of trito it. . While, analogous, 1 Megaton = 1.000.000 of tons of
trito it. . For giving an idea, the most large bombs of airplane never
constructed carry little less than one ton than trito it. . The bomb exploded to
Hiroshima was of 12 Kiloton, equivalent that is to the simultaneous outbreak of
12.000 of these bombs. . The bomb of Hiroshima was relatively small. . The power
of the modern bombs measure in Megaton, from 0,1 to 10 Megaton approximately.
. And when it
explodes?
. The outbreak of an atomic bomb produces the
strongest light that can instantaneously render Czechs, of continuation forms an
incandescent compressed gas mass, dictates fire ball whose temperature catches
up the miglioni of temperature degrees c, all the one which is found inside of
this ball comes at once vaporizzato. . The largeness of the fire ball depends on
the power of the device, one bomb of 10 kiloton forms one ball with diameter of
approximately 300 m; for an outbreak from 10 megaton the diameter catches up
instead i 5 km.
.
From the fire ball it comes emitted a shock wave of thermal cancellation that an
immense area catches up, even though with intensity that decreases in constant
way. . The amount of received thermal energy to one determined distance from
ground zero depends on the power of the bomb and the state of the atmosphere: if
the visibility is insufficient and the outbreak happens to of over of clouds, as
an example, the effectiveness of the lightning bolt of thermal cancellation that
turns out some considerably is diminished.
. In order to give to greater
destructive effect the bomb it comes made to explode to one determined altitude
rapportata to its power, in this way the direct shock wave comes amplified with
which it reflects on the ground.
. The residual nuclear cancellations from the crescent continuous
fire ball to catch up the ground. . But after 3 second (or 11, to second of the
bomb) the fire ball, although it is still a lot hot, it begins to cool off
itself with a such extension that the thermal cancellation does not have more
importance. . The hot fire ball raises a lot quickly. . As soon as it rises, ago
so that the air is pushed towards the bottom and the high, just like the
traction in on a fireplace. . That produces to forts airflows moderately more
bottoms: these twenty will raise detritus of the land surface in order to form
the stem of that it will be the characteristic shape of fungus.
. The
thermal cancellation can provoke the fire development of combustible material
that extends if the conditions are favorable. . The collected data as a result
of the atomic outbreaks on the two Japanese cities revealed that many fires,
especially in the area around ground zero, were provoke to you from secondary
causes, like short circuits, breaches of the ducts of the gas, breach of the
furnaces and the boilers of industrial systems. . The shock wave produced
detritus that contributed to feeding flames and to hinder the job of who it
tried to tame them.
. In particular conditions, which were taken place to
Hiroshima and not to Nakasaki, many single fires can be arranged to produce one
great fire storm. . The heat of the fire cause one strongly upward airflow,
which in its turn recalls strong twenty towards the center of the interested
area; these twenty feed flames and in the area all that that exists of
inflammable comes quickly divorato from the fire.
. The thermal cancellation
that hits the skin cause serious ustioni, in particular an outbreak in quota
from 10 kiloton can produce to ustioni of second degree on the skin not blanket,
until 2,4 km from ground zero; for a bomb from 10 megaton, the corresponding
distance is of 32 km.
. Beyond to the heat and the shock wave, the outbreak
of a bomb nuclear has a particular and completely absolutely devastating effect:
the instantaneous emission of neutrons and range beams, that they are
electromagnetic cancellations to high energy similar to i beams X, on an area of
very many square kilometers. . It is the neutrons is the range beams have the
property to cross the matter to the solid state, so that in order to defend
itself from their action it is necessary to be shielded from spessori consisting
of material.
. When it comes absorbed from the corporei woven ones, the
cancellation nuclear can cause extremely serious damages even if, for an
outbreak in quota, these are manifested inside of a smaller beam regarding that
associate to a shock wave and the thermal cancellation. . In Japan, however,
many individuals that had not received lethal damages for the collision and the
heat, died in according to moment because of the cancellations.
. Sonar altimeter
. We have inasmuch as an atomic
bomb does not come made to explode when it touches the ground, but comes made to
detonate to a sure altitude based on the power therefore that the wave durto
comes increased with the reflection on the ground. . Therefore it has had to
install on the bomb an altimeter that calculated the altitude with one sure
precision in order to make it to explode to the calculate distance.
. Of
usual a normal altimeter of airplane uses a type of barometer that measure the
changes of the pressure of air to different altitudes. . However, the changes in
the air pressure which had to the atmospheric time can negatively influence the
readings of the altimeter. . Decided therefore to use a system radar used also
in the submarines. . As simple systems to pulsation, come emitted mark them from
the radar place in the bomb, which bounces on the ground comes receipts through
the reflection on the ground from the altimeter of the bomb that automatically
calculates the altidudine to second of the time that the impulse employs in
order to return to the device. . The precision of these altimeters is between
the meter and means for the variable ones of the greater heights. . But if this
system is cosi precise because is not adopted also on the airplanes? . Simply
because these systems are mooolto expensive and therefore “not prati
us” for the civil use.
. fallout
. Even if what it has been said
over would seem the more dangerous effect of the bomb is not therefore, the
fallout and considered the more dangerous effect. . The cancellation nuclear
residual, generally famous like fallout, can represent a risk for completely
undamaged immense areas much from the other effects of the outbreak. . In the
bombs that draw energy from the fission of uranio 235 or plutonio 239, for every
fissile atom you produce yourselves to two radioactive nuclei; these products of
fission explain the persistent radioactivity of detritus of the bombs, from the
moment that many of atoms have half lives of days, months or also years. . Two
various categories of fallout are known: premature and delayed. . If an outbreak
nuclear verification close to the surface, happens the whirpool from the same
detritus surface and water, materials that go to constitute the cloud to fungus
and are contaminated with the residual ones radioatti you of the same bomb. .
The contaminated material begins to fall back in the turn of little minuteren
and can continue also for 24 hours, interesting an area of migliaia of square
kilometers leeward regarding the point of the outbreak: the premature one is
this so-called fallout, that it constitutes an immediate risk for the human
beings. . The outbreaks that happen to relatively high quota do not give place
fallout premature. . If a bomb nuclear explodes very far from the ground, the
residual ones radioatti to you go up to high quota in the cloud to fungus, and
gradually fall back on an area much immense one.
. The nature of the
radioactivity and the great vastness of the areas that could be contaminated
from a single outbreak potentially render fallout radioactive one of the
deadlier effects of the nuclear outbreaks, in fact these devices do not come use
you in the wars only for the problem of the fullout today and not for the
devastating destruction that they provoke at once. . Among other things this is
also the large danger of centers them electrical workers who take advantage of
the fission (see Cernobyl).
. EMP effect
. Effect
“EMP”: This effect was uncovered in years '60, later on to
nuclear outbreaks experiences them. . Acronym EMP is for ElectroMagneticPulse
that is electromagnetic impulse. . We have asserted that an outbreak nuclear
provokes one great q uantit�f cancellations, between here those electromagnetic
ones. . This upsets for a sureevery period 
. electronic system or electrical worker on one immense area. . This
effect is not, of for himself, lethal but it does not have to forget that all
the instruments of control of the modern nuclear arsenals are electronic (even
if after systems like the fiber optic were studied that does not endure some
disturbance). . In a hypothetical war nuclear, to a “first opposing
blow” not only enormous destructions, but also, a lot probably, the
practical inability would correspond to control just the arsenal. . The launch
bombs, lacking in every system of tracking and control-guide, could fall in the
impensati places. . This effect to fact that after the outbreak of the bomb on
. Hiroshima . the remained clocks intact remained
firm to the hour of the outbreak.
. Nuclear winter
. This effect is one of the
possible consequences more nuclear outbreaks. . Ognuna of they will raise a
great powder amount that for months will remain suspended in the atmosphere. .
E' be assumed that the powder amount such is sufficient in order to shield the
beams of the sun and to provoke, therefore, a lowering of the medium temperature
of the planet of some degree. . That would be sufficient to provoke to the
passing of much species animals and vegetables. . This effect has not been, for
the truth, uncovered, but only previewed on the base of calculations, whose
validity still must be tried. . There is who thinks, as an example, that minor
the amount of heat arrived on the earth would be compensated from one risen of
effect greenhouse, provoked from same powders. . It is not therefore clear if
the temperature would diminish, would remain invariata or, quite, it would
increase..