Uranium

Uranium has been detected in 1789. Has received the title from German scientist Martin Heinrich Klaproth who has named an open unit, owing to the event which have happened for some years before it and excited all circles of a company. In 1781 the English astronomer William Herschel, watching by means of a self-made telescope the star-shaped root, has detected a flashing cloudlet which one it has first taken over for a comet, but further was convinced, that sees new, unknown until then the seventh planet of a solar system.

In honour of the Ancient Greek god of root Herschel has named its Uranium. The were hearth impression of this event, Klaproth has named a neonatal unit of a new planet.

Grass-snake in 1841, after approximately half a century, French chemist Eugene-Melchior Peligot has managed for the first time to receive metallic uranium.

The industrial world remained to indifferent to heavy-duty, rather soft metal uranium has appeared what. Its mechanic and chemical properties have not attracted neither metallurgists, nor machine engineers. Only glass blowers Bohemia yes saxons the master of porcelain and faience matters willingly applied monoxide of this metal to attach glasses beautiful yellow-green colour or to decorate dishes with an intricate barhatno-black pattern.

Ancient Romans knew about “art capabilities” uranic joints still. At the excavations conducted near of Naples, it was possible to discover a glass mosaic fresco of surprising beauty. Archeologists have been attacked: for two millenaries of a glass have not become dull almost. When formation samples of glasses have exposed a chemical analysis, it has appeared, that at them is present uranium oxide which one the mosaic and has been bound by the longevity. But, if oxides and uranium salts were occupied “socially by a useful labour” metal in the pure state almost interested nobody.

Even scientists, and those were only rather superficially familiar with this unit. Clearings on him were poor, and occasionally are absolutely wrong. So, was considered, that its atomic weight is peer approximately 120. When Dmitri Mendeleev created the Periodic system, this rate confused to it all maps: uranium on the properties in any way did not wish to be inscribed in that cell of the table which one has been reserved"behind a unit with this atomic weight. And then the scientist, contrary to judgement of many colleagues, has decided to take over new meaning of an atomic weight of uranium - 240 and has tolerated a unit to the table extremity. Life has confirmed correctness of the great chemist: an atomic weight of uranium 238,03.

But genius Dmitri Mendeleev was displayed not only in it. In 1872 when the majority of scientists considered uranium against many valuable units some kind of "ballast", the Periodic system creator has managed to foresee it indeed the bright future: “Between all known chemical elements uranium precipitates out that has the best atomic weight... The Best, from known, a pulp density of powerful material... Existing in uranium... Should involve behind itself outstanding singularities... Convinced that uranium probe, since its natural radiants, will lead even to many new openings, I dared I recommend to those who searches subjects for new probes, especially carefully to be occupied by uranic joints”.

The forecast of the great scientist has come true less than in quarter of the century: in 1896 the French physicist Henri Becquerel, making experiments with uranium salts, has committed opening which one by right concerns to the greatest discoveries, ever the made person. Here is how it has happened. Becquerel for a long time was interested in a phosphorescence appearance (i.e. Light emissions), inherent in some materials. Once the scientist has decided to use for the experiences of one of salts of uranium which one chemists name double-face uranyl sulphate and a potassium. On the photoplate wrapped by a black paper it has seated the figured figure cut from metal covered with bed of uranic salt, and has advanced it on a bright sun light that phosphorescence was as more as possible intense. In four hours Becquerel has displayed a blade and has seen on it a clear outline profile of a metallic figure. More and more time he has retried the experiences - the effect was the same. And here on February, 24th, 1896 at conference of the French Academy of sciences the scientist has reported, that for such noctilucent material as double-face uranyl sulphate and the potassium exhibited on light, is watched invisible irradiation which one drives through a black opaque paper and reduces silver salts on a photoplate.

After two days Becquerel has decided to prolong experiments, but as ill-luck would have it weather there was overcast, and without the sun what phosphorescence? Being annoyed with a bad weather, the scientist has hidden already prepared, but and not subjected to illuminating lantern slides together with formation samples of salts of uranium in a container of the desktop where they have lain some days. At last, on the night of March, 1st the wind has cleared the Parisian root of clouds and sun rays since morning have begun to sparkle over a city. Becquerel, with impatience expecting it, has hastened in the lab and has extracted from a container of desktop lantern slides to advance them on the sun. But, being very pedantic experimenter, he nevertheless has decided at the last minute to display lantern slides though the logic, apparently, suggested, that for the past days with it could happen nothing: after all they lied in a dark container, and without light any material does not phosphoresce. During this instant the scientist did not suspect, that in some hours to routine photographic planes by in some francs, it is fated to become invaluable treasure, and day for ever will become history on March, 1st, 1896 of a world science.

That Becquerel has seen on the displayed blades, has literally attacked it: black outline profiles it is exemplary sharply and accurately were marked out on the light-sensitive layer. Means, phosphorescence here at anything. But then, what it for rays irradiates uranium salt? The scientist again and again makes analogous experiences with other joints of uranium including with what had no capability to phosphoresce or years lied in a dark place, and each time on blades there was a plotting.

For Becquerel there is for the present not quite clear thought, that uranium represents "the first instance of the metal finding property, look-alike to invisible phosphorescence".

In the same time the French chemist Henri Moissan managed to develop a mode of obtaining of pure metallic uranium. Becquerel the uranic dust has asked for Moissan a little and has positioned, that irradiation of pure uranium is much more intense, than its joints, and this property of uranium remains immutable under the most various conditions of experiences, in particular at strong calefaction and at refrigeration to low temperatures.

With the publication of new data Becquerel did not hurry: he waited, when Moissan will report about the rather interesting probes. To it scientific ethics obligated. And here on November, 23rd, 1896 at conference of Academy of sciences Moissan has given the report on jobs on obtaining of pure uranium, and Becquerel has told about the new property inherent in this unit which one consisted in spontaneous partition of kernels of its atoms. This property has been named by a radioactivity.

Opening Becquerel has marked itself a kickoff of a new era in the physicist - ages of a transmutation of elements. Henceforth the atom could not be considered uniform any more and indivisible-before a science the path to depths of this "brick" of a material world opened. It is natural, that now uranium has riveted on itself attention of scientists. At the same time them such problem interested also: whether only a radioactivity is inherent in uranium? Perhaps, in the nature there are also other units having this property?

Outstanding physicists of spouse Pierre Curie and Maria Sklodowska-Curie could yield the answer to this problem. By means of the gauge constructed by the husband, Marie Curie researched a large quantity of metals, minerals, salts. Job was led in extremely heavy conditions. For lab the thrown wood barn which one spouses have sought in one of the Parisian yards was. "It was a cabin from boards, with an asphalt floor and a glass roof badly protecting from a rain, without any devices, - recalled subsequently Marie Curie. - In him there were only old wood desktops, the cast-iron oven, not yielding is warm enough, and the blackboard which one so liked to use Pierre. There there were no draught cupboards for experiences with noxious gases, therefore it was necessary to make these processes on a palace when weather allowed, or indoors at open windows". In diary Pierre Curie there is a tracing that the job pore made at the temperature of only six grades above null.

Many problems originated and with obtaining of the necessary materials. Uranic ore, for example, was very expensive, and purchase on the retiring tools enough her spouses Curie could not. They have decided to revert to the Austrian government with the request to sell it under the low-level price scrap of this ore from which one in Austria extracted the uranium used in the form of salts for colouring of a glass and porcelain. Scientists were bolstered viennes by Academy of sciences, and some tons of scrap have been forwarded in their Parisian lab.

Marie Curie worked with unusual persistence. Learning of diverse materials acknowledged correctness Becquerel, considering, that a radioactivity of pure uranium more than its any joints. About it spoke effects of hundreds experiences. But Marie Curie exposed probes all new and new materials. And suddenly... Unexpectedness! Two uranic minerals - Torbernite and rosin ore Bohemia - acted on the gauge, than uranium much more actively. The leading-out arose by itself: they maintain any unknown unit defined by higher capability to a radioactive decay. In honour of Poland - Rhodinums Marie Curie-spouses have named its polonium.

Again for job, again titanic transactionses - and more victory: the unit, in hundreds times uranium exceeding on a radioactivity is detected. This unit scientists have named radium, that in Latin means "ray".

Radium opening in any measure has sidetracked scientific community from uranium. Within approximately forty years it not so stirred minds of scientists, and engineering thought seldom indulged its attention. In one of volumes of the engineering encyclopaedia, published in 1934, it was claimed: "Elementary uranium of operational use has no". The solid publication did not violate the truth, but after all some years life has introduced significant corrective amendments in representations about possibilities of uranium.

In a kickoff of 1939 there were two scientific reports. First, routed to the French Academy of sciences Frederic Joliot-Curie, the Experimental demonstration of explosive fission of kernels of uranium and thorium under the influence of neutrons "has been entitled". The second report - German physicists Otto Robert Frisch were its authors and Lise Meitner - has published the English register "Nature"; it was called: "Disintegration of uranium by neutrons: a new type of nuclear reaction". Both there, and there it was a question about new, hitherto the unknown appearance happening to a nucleus of the heavy-dutiest unit - uranium.

For some years before the bunch of the young talented physicists working under the guidance of Enrico Fermi at Roman university has become seriously interested in uranium. The neutronics concealing in many new, unknown was entrainment of these scientists.

It was revealed, that at a neutron exposure, as a rule, nucleuses of one unit turn to nucleuses of other, occupying a following cell in the Periodic system. And if to irradiate with neutrons last, 92nd unit-uranium? Then the unit, standing a grass-snake on 93rd place-unit which one the nature could not create even should be derivated!

The idea was pleasant to scientists. Still, unless is not tempting to learn, what itself presents an artificial unit how it looks how behaves? So, uranium is irradiated. But what has happened? In uranium there was not one radioelement, predictably, and at least, ten. Any puzzle in behaviour of uranium was available. Enrico Fermi submits a report about it in one of scientific registers. Was possiblly, he considers, 93rd unit was derivated, but exact demonstrations of it are not present. But, on the other hand, there are demonstrations, that at the irradiated uranium are present any other units. But what?

Trying to answer on this problem has undertaken daughter Marie Curie - Irene Joliot-Curie. She has retried experiences Fermi and carefully researched chemical composition of uranium after bombarding radiation by its neutrons. The effect was more than unexpected: in uranium there was the unit of lanthanums which is laying out approximately in the middle of the table of Mendeleyev, i.e. Very away from uranium.

When the same experiments were done by German scientists Otto Hahn and Fritz Strassmann, they have discovered in uranium not only lanthanum, but also barium. A puzzle behind a puzzle!

Hahn and Strassmann have reported about the conducted experiences to the friend to known physicist Lise Meitner. Already the largest scientists try to decide an uranic problem at once some. And here, at first Frederic Joliot-Curie, and and it came to pass Lise Meitner come to the same leading-out: at hit of a neutron the uranium nucleus as though collapses on a part. It unexpected emergence of lanthanum and barium - units with an atomic weight, approximately twice smaller, than for uranium also speaks.

American physicist Luis Walter Alvarez, subsequently the Nobel prize winner, this information has found in one January morning 1939 in a seat of the hairdresser. It easy scanned a newspaper as suddenly to it the retiring title was evident: "the Atom of uranium is divided into two halfs".

An instant later to amazement of the hairdresser and the visitors expecting queue, the strange client has run out from a hairdressing salon, half cut, with a napkin tightly fastened round a neck and fluttering on a wind. Not paying attention to the surprised passers-by, the physicist rushed in lab of the Californian university, where it worked to report about tremendous news to the colleagues. Those first have been dumbfounded rather by an original form swinging newspaper Alvarez, but when have heard about sensational opening, have by and by forgotten about its unusual hairdress.

Yes, it was the genuine sensation in a science. But Joliot-Curie has positioned also other major fact: dissolving of an uranic nucleus has character of shot at which one organised chips fly apart in the sides with huge velocity. While it was possible to crack only separate nucleuses, energy of chips only heat uped an uranium chunk. If the figure of partitions is great, the energy large quantity thus will precipitate out.

But where to get such quantity of neutrons, simultaneously to bombard them large figure of kernels of uranium? After all neutron-sources known for scientists yielded them in many billions times less, than it was required. The nature To the aid has come. Joliot-Curie has detected, that at nuclear fission of uranium from it some neutrons depart. Having got in nucleuses of adjacent atoms, they should lead to new dissolving - the so-called chain reaction will start. And as these processes last a parts per million of sec, enormous energy - at once will precipitate out shot is imminent. It would Seem, all is clear. But after all uranium chunks more than once irradiated with neutrons, and they thus were not blasted, i.e. The chain reaction did not originate. Probably, any conditions are necessary still. What? To this problem Frederic Joliot-Curie to respond could not yet.

And still the answer has been discovered. Young Soviet scientists Yakov B have discovered it in the same 1939. Zel'dovich and Yulii B. Khariton. In the jobs they have positioned, that there are two paths of development of chain nuclear reaction. First - it is necessary to augment sizes of a chunk of uranium as at bombarding radiation of a small chunk many neutrons precipitated out again can depart from it, not having met on the path of any nucleus. With growth of pulp of uranium the neutron hit probability in the purpose, naturally, increases.

There is also other path: upgrading of uranium by an isotope 235. The matter is that natural uranium has two basic isotopes which one atomic weight is peer 238 and 235. In a nucleus first from them on which one fraction it is necessary in 140 times more atoms, is present on three neutrons more. "Poor" neutrons uranium-235 greedy captures them - much more strongly, than its "rich" brother who is not divided at all into parts, and turns to other unit. Scientists used further this property of an isotope for obtaining of artificial transuranic elements. For chain response the indifference of uranium-238 to neutrons appears pernicious: process perishes, not having had time to gain in strength. But the more in uranium "greedy" to neutrons of atoms of an isotope 235, the response will more vigorously go.

But, that process has started, is necessary also the first neutron "match" which one should call atomic "fire". Certainly, for this purpose it is possible to use routine neutron sources, which one scientists and applied earlier in the probes, - is is not so friend, but it is possible. And whether there is no more eligible "match"? Is. It was discovered by other Soviet scientists K.A. Petrjak and G.N. Flerov. Researching in 1939-1940 behaviour of uranium, they have come to conclusion, that nucleuses of this unit are capable to decompose spontaneously. It was confirmed by effects of the experiences conducted by them in one of the Leningrad labs. But, maybe, uranium decomposed not itself, and, for example, under the influence of ultrarays: after all the Earth continuously is under their raking. Means, experiences need to be retried deeply underground where these space visitors do not make through. Having advised with the largest Soviet scientist-atomnikom I.V.Kurchatov, young contributors have decided to make experiments on any server of the Moscow underground railway. In Narkomat means of communication it has not met hardles, and soon in a cabinet of the railhead commander of metro "Dinamo", 50 metres which were on depth, on shoulders of science officers hardware which one weighed about three tons has been forwarded.

As always, by drove subway trains, thousand passengers were tapped off and rose on the moving stairway, and anybody from them did not guess, that somewhere absolutely experiences which one meaning is difficult for revaluating nearby are led. And here, at last, the effects analogous to what were watched in Leningrad are received. Doubts were not: an autodecomposition is inherent in uranium nucleuses. To note it, it was necessary to display uncommon experimenter skill: for 1 hour from each 60 000 000 000 000 atoms of uranium decompose only one. Indeed - a drip at-sea! K.A. Petrjak and G.N. Flerov have added final page to that part of the biography of uranium which one preceded realisation of the first-ever chain reaction. It has performed on December, 2nd, 1942 Enrico Fermi.

In the late thirties Fermi, as well as many other things large scientists, being salvaged from hitler’s plague, have been compelled to emigrate to America. Here he intended to prolong the major experiments. But for this purpose many money was required. It was necessary to convince the American government that experiences Fermi will allow to receive the heavy-lift atomic weapon which one can be used for a control with fascism. This mission was incurred by the scientist with world name Albert Einstein. He writes a letter to US president Franklin Delano Roosevelt which one starts words: "In the course of the last four months it has been made probable - through the work of Joliot in France as well as Fermi and Szilard in America - that it may become possible to set up a nuclear chain reaction in a large massive of uranium, by which vast amounts of power and large quantities of new radium-like elements would be generated. Now it appears almost certain that this could be achieved in the immediate future." . In a letter the scientist urged the government to start financing of operations on uranium probe. Noting huge authority Einstein and severity of an international situation, Roosevelt has yielded the consent.

In the end of 1941 inhabitants of Chicago could note reigning on terrain of one of stadiums unusual revival which one had no to sport the slightest ratio. Vehicles continually approached on its gateway with a freight. Multiple preservation did not authorise strangers even to come nearer to a stadium pale. Here, on the tennis courts which have been had under western tribune, Enrico Fermi prepared the most dangerous experiment - implementation of a controllable chain reaction of partition of kernels of uranium. Jobs on structure of the first-ever nuclear reactor were led day and night in the course of the year.

There has stepped morning on December, 2nd, 1942. All night long scientists did not close eyes, again and again mustering accounts. Whether the joke to tell: the stadium is at the centre of a mullions-strong city and though accounts convinced that response in the atomic boiler will be decelerated, i.e. Will not wear explosive character, to risk life of hundreds thousand people had nobody the rights. Day has started for a long time already, it was time to have breakfast, but all have forgotten about it it-would be necessary to get down to atom storm as soon as possible. However Fermi does not hurry up: it is necessary to yield the tired people to rest, relaxation that then again all carefully to weigh and consider is necessary.

Guard and more time guard. And here, when all waited the command to start experiment, Fermi has said the well-known phrase which has become history of conquest of atom,-only few words: "Let’s go for a breakfast!".

The lunch behind, all on the places - experience starts again. Views of scientists are chained to gauges. Minutes of waiting are painful. And, at last, counters of neutrons have earned, as machine guns. They as if choked with a large quantity of neutrons, not being in time them to consider! The chain reaction has started! It has happened at 15 o'clock 25 minutes on Chicago time. To atomic light 28 minutes have allowed to burn, and then by command Fermi the chain reaction has been stopped.

One of participants of experiment has approached to the earphone and in advance agreed encoded phrase has reported to the heads: "The Italian sailor reached the new world!" It meaned, that outstanding Italian scientist Enrico Fermi has relieved energy of an atomic nucleus and has proved, that the person can check and use it on the will.

But, those years when there were presented events, the chain reaction was observed first of all as a stage on paths to atomic bomb building. In this direction in America jobs of scientists-atomshchikov also have been prolonged. Environment in the scientific circles bundled to these jobs, was the extremely intense. But also here did not do without funny things.

In the autumn 1943 has been decided to try to haul from the Denmark occupied by germans to America the largest physicist Niels Bohr to use its colossal knowledge and talent. At dark night on the fishing little craft secretly guarded by the English submersibles, the scientist under the pretext of the fisherman has been forwarded to Sweden, whence it on the airplane should ferry to England, and grass-snake then in the USA. All baggage Bohr consisted of one bottle. From under the Danish beer in which one it secretly from germans stored invaluable deutoxide, the physicist cherished this routine green bottle as the apple of the eye: according to many scientists-atomnikov, deutoxide could be for a moderator of neutrons for nuclear reaction.

Bohr has very hardly tolerated tiresome flying and as soon as has come to the senses, has first of all mustered, whether is whole a bottle with deutoxide. And here, to the great affliction, the scientist has detected, that became a victim of characteristic absent-mindedness: in his hands there was a bottle with the real Danish beer, and the bottle with deutoxide remained at home in a cooler.

When on jumbo production plants Oak Ridge, Tennessee, the first small scrap of uranium-235 designed for an atomic bomb has been received, it have shipped with the special courier in Los Alamos, New Mexico where there was this deadly weapon. To the courier who should most drive the car, have not told, that is in the pod pitched it, but he heard time and again terrible histories about mysterious "mors rays", born in Oak Ridge. The further it went, the larger agitation overlapped it. In long run, he has decided, at the first suspicious tag in behaviour of the pod hidden behind it, to run from the vehicle that is urine.

Driving on the long bridge, the driver has suddenly heard behind a loud shot. As if catapulted, it has jumped out of the car and has run so sweepingly as still never ran in the life. But here, having transversed fair spacing interval, it was shut down in exhaustion, convinced, that safe and sound, and even has ventured to look back. And in the meantime behind its vehicle the long tailing of impatiently signalling cars has already grown. It was necessary to be reverted and prolong a path.

But hardly it has sat for a rudder as the loud shot was again distributed, and the self-preservative instinct again has literally rejected the poor creature from the vehicle and has caused to rush away from an ill-starred pod. Only after the angered policeman has caught up with it on a motorcycle and has seen the governmental deeds, the scared driver has learnt, that shots reached from adjacent proving ground where at this time tested new ammunition gears.

Approximately in the middle of 1945 of job on atomic bomb building for which one it has been expended two billion bucks, were completed, and on August, 6th over the Japanese city of Hiroshima there was the jumbo igneous fungus, entrained ten thousand life. This date became a rainy day in civilisation history. The greatest reaching of a science has spawned the greatest tragedy of mankind.

Before scientists, before all world there was a problem: what further? To prolong to perfect automatic weapon, to create even more awful removers of people?

No! Henceforth the enormous energy concluded in nucleuses of atoms, should be the person. The first step on this path was made by the Soviet scientists under the guidance of the academician And. V.Kurchatova. On June, 27th, 1954 the Moscow radio has pitched the report of exclusive relevance: "Now in Soviet Union force of the Soviet scientists and engineers successfully completes jobs on projection and construction of the first industrial electric power plant on an atomic energy by a net power of 5000 kilowatts". For the first time via wire there was a current which one carried the energy born in a mineral resources of atom of uranium.

"This historical event, the newspaper" Daily Worker "-wrote those days,-has nonmeasurably larger international meaning, than fault of the first atomic bomb to Hiroshima...".

Start-up of the first nuclear energy station has laid foundation to developing of new branch of machinery - nuclear power. An Uranium became nonpredatory fuel of the XX-th century.

Has driven as early as five years, and the first-ever atomic-powered icebreaker has descended from slipways of the Soviet shipyards "Lenin". To cause to work its propellers in all power (44 thousand horse powers!), it is necessary to "burn" all some tens grammes of uranium. The small chunk of this nuclear fuel is capable to change thousand tons of fuel oil or of mineral coal which one are compelled to trail in the literal sense behind itself the routine motorships committing, for example/flight London-New York. And nuclear-powered vessel "Lenin" with a reserve of uranium feed some tens kilogrammes can crush within three years ices of Arctic regions, not coming in in port on "batch".

In 1974 "even more heavy-lift atomic icebreaker -" Arctic "has got down to modification of the responsibilities".

Every year the fraction of nuclear fuel in world balance of power resources all becomes senser. Advantages of this fuel are doubtless. But it is not necessary to forget about a hazard of radiation. Million people has suffered. Among them more than 100 000 have perished because of awful failure on the Chernobyl atomic power station in 1986. And now the terrain nearby Chernobyl Nuclear Power Plant is infected and is not suitable for life. Will drive yet less than hundred years before the person can come back and live there. But also without failures not so all is plain. After all uranium feed utilisation is interfaced to many difficulties, from which one hardly probable not the major - extermination of an organised radioactive waste. To tap off them in special containers for a bottom of seas and oceans? To earth them it is deep? Hardly such modes will allow to troubleshoot completely: after all in the final reckoning killing materials thus remain on our planet.

Whether instead of to try to ship them somewhere further th other celestial bodies? Such idea was pushed by one of the scientific USA. He has tendered to land scrap of nuclear energy stations on the "hauling" orbiting space crafts following on route the Earth-sun. Certainly, today look-alike "feeds per oscillation" would cost much to senders, but, according to some optimistically tuned specialists, these transportation quite justified become more narrow in 10 years.

Presently not so bindingly to have rich imagination, to forecast the great future of uranium. An Uranium tomorrow-it the space missiles let into the depth by the Universe, and the jumbo diving cities ensured with energy on tens of years, this building of artificial islands and water-supply development of deserts, this infiltration to the mineral resources of the Earth and conversion of a climate of our planet.

Fantastic prospects uranium - perhaps detects before the person, the most surprising metal of the nature!