Fission nke uranium nuclei. Chain mmeghachi omume. Description nke usoro

Nkerisi isi - a arọ atọm kewara abụọ iberibe ihe dị hà ibu, sochiri ntọhapụ nke a nnukwu ego nke ike.

The chọpụtara nke nuclear fission mmalite nke a n'ọgbọ ọhụrụ - "atọm afọ". The nwere nke ya na o kwere omume ojiji na nke itule nke ize ndụ na-erite uru na ya iji, ọ bụghị nanị anana-a otutu sociological, ndọrọ ndọrọ ọchịchị, akụ na ụba na ndị ọkà mmụta sayensị rụzuru, ma a oké nsogbu. Ọbụna site na a kpere ọkà mmụta sayensị na-ekwu, na nuclear fission usoro kere a ukwuu nke mgbagwoju anya na nsogbu, na a zuru usoro iwu nkọwa n'ihi na ọ bụ a ihe nke ga-eme n'ọdịnihu.

Ịkekọrịta - bara uru

nkịtị ume (kwa nucleon) dị iche na iche iche nuclei. Arọ nwere a ala-adịgide adịgide ike karịa na nke dị na etiti oge table.

Nke a pụtara na arọ nuclei nke atọm nọmba ukwuu karịa 100, advantageously kewara abụọ nta rifọrọ, si otú atọhapụ ike nke na-converted n'ime kinetic ike nke akwụkwọ ya. Nke a usoro a na-akpọ gbawara atọm ntọala.

Na dị na kwụsie ike usoro, nke na-egosi na nduzi nke ọnụ ọgụgụ ndị protons si anụ nuclides maka neutron arọ ntọala ahọrọ a ibu ọnụ ọgụgụ nke neutrons (tụnyere ọnụ ọgụgụ nke protons) karịa n'ihu. Nke a na-egosi na na mgbakwunye na nke kewara usoro ga-enwupụta ụfọdụ "mapụtara" neutrons. Ọzọkwa, ha ga-weghara ụfọdụ nke na ike. Study fission nke uranium atọm gosiri na nke a site na a neutron 3-4: U → ^{238 145 90} La + br + 3n.

The ọnụọgụ nzùrùòkè (na atọm uka) nke papaịrọs ahaghị nhata ọkara ndị atọm uka nke nne na nna. Ihe dị iche n'etiti ọha mmadụ nke atọm guzobere n'ihi nke cleavage na-abụkarị banyere 50. Otú ọ dị, ihe mere nke a bụ ma kpamkpam doro anya.

The nkịtị ume nke ²³⁸ U, ¹⁴⁵ La br na ⁹⁰ bụ 1803, 1198 na 763 MeV karị. Nke a pụtara na ike a tọhapụrụ uranium fission hà 1198 + 158 = 763-1803 MeV n'ihi mmeghachi omume.

n'amaghi fission

n'amaghi gbawara Filiks na-mara na ọdịdị, ma ha dị nnọọ obere. The n'oge ndụ nke usoro a bụ banyere 10 ^17, na, ka ihe atụ, n'oge ndụ nke Alfa-ire ere nke radionuclide bụ banyere 10 ^11.

Ihe kpatara nke a bụ na iji ikewapụ abụọ akụkụ, ndị isi ga-akpa na-ata deformation (gbatia) na ihe ellipsoidal ụdị, na mgbe ahụ, tupu ikpeazụ cleavage abụọ iberibe na-etolite a "n'olu" n'etiti.

nwere mgbochi

Na oruru obodo na isi nke abụọ agha. Otu n'ime ha - ụba n'elu ume (n'elu erughị ala nke mmiri mmiri ụmụ irighiri mmiri na-akọwa ya * Tụkwasị na udi), na ndị ọzọ na - na Coulomb repulsion n'etiti fission iberibe. Ha na-emepụta nwere mgbochi.

Dị ka n'ihe banyere Alfa ire ere ime n'amaghi fission nke uranium atọm nuclei, na iberibe ga esi merie nsogbu a site kwantum tunneling. The mgbochi bụ banyere 6 MeV, dị ka n'ihe banyere Alfa-ure, ma gbasara nke puru omume tunneling nke α-ahụ bụ nke ukwu ukwuu karịa ihe arọ ngwaahịa gbawara atọm.

amanye umuihe

Ọtụtụ ihe ndị ọzọ yiri na-akpata fission nke uranium nuclei. Na nke a, ndị nne na nna ntọala na-ụzarị ọkụ neutrons. Ọ bụrụ na nne na nna ya na-amịkọrọ, mgbe ahụ, ha na-agbụ na hapụ nkịtị ike n'ụdị ọma jijiji na ike nke na-nwere ike gafere 6 MeV mkpa iji merie nwere mgbochi.

Ebe ọzọ neutron ike bụghị iji merie nwere mgbochi, ihe ahụ merenụ neutron ga nwere a kacha nta kinetic ike iji na-enwe ike ime ka gbawara nke atọm. Na ikpe nke ²³⁸ U ọzọ neutron adịgide adịgide ike na-efu banyere 1 MeV. Nke a pụtara na fission nke uranium nuclei rata naanị neutrons na a kinetic ume ukwuu karịa 1 MeV. N'aka nke ọzọ, ndị ²³⁵ U isotope nwere otu unpaired neutron. Mgbe a ntọala amịkọrọ ọzọ, ọ Nleta na ya a di na nwunye na ihe ọzọ na-adịgide adịgide ike bụ a N'ihi nke a pairing. Nke a bụ zuru ezu iji hapụ ego nke ike dị mkpa iji merie nwere mgbochi nke ntọala na nkewa nke isotopes mere na a nkukota na bụla neutron.

beta ire ere

N'agbanyeghị eziokwu na fission mmeghachi omume na-enwupụta atọ ma ọ bụ anọ neutrons, iberibe ka ebu ihe neutrons karịa ha anụ isobars. Nke a pụtara na cleavage iberibe bụ n'ozuzu na-ejighị n'aka na-akwanyere beta ire ere.

Ka ihe atụ, mgbe e nwere bụ a nkewa nke ntọala nke uranium ²³⁸ U, anụ isobars na A = 145 ¹⁴⁵ bụ neodymium nd, nke pụtara na ibe akwụkwọ lanthanum La ¹⁴⁵ gbawara agba atọ, oge ọ bụla site radiating elektrọn na a neutrino ruo mgbe a ufọk ufene nuclide a kpụrụ. Anụ isobars na A = 90 ⁹⁰ bụ zirconium Zr, otú cleavage papaịrọs bromo br ⁹⁰ gbawara n'ime ise nkebi yinye β-ire ere.

Ndị a yinye β-ire ere emit extra ike nke a na-dọrọ fọrọ nke nta niile nke elektrọn na a neutrino.

Nuclear Jeremaya mere: fission nke uranium

Direct nuclide si neutron radieshon na oke buru ibu ọnụ ọgụgụ nke ha iji hụ na nkwụsi ike nke ntọala bụ eleghi anya. Ebe a na-ekwu bụ na ọ dịghị Coulomb repulsion, na n'elu ike nēche anọgide na neutron n'ihi na nne na nna. O sina dị, mgbe ụfọdụ ọ na-eme. Ka ihe atụ, fission papaịrọs br ⁹⁰ ke akpa beta-ire ere na-arụpụta a krypton-90, nke nwere ike dị na ihe obi ụtọ ikwu na ezu ike imeri elu ike. Na nke a na neutron radieshon nwere ike ime ozugbo na-etolite a krypton-89. Nke a isobars bụ ka ejighị n'aka na-akwanyere beta-ire ere bụghị ma na-aga n'ime anụ yttrium-89, nke mere na krypton-89 na-agba atọ.

Uranium fission: Chain Mmeghachi omume

Neutrons enwupụta na cleavage mmeghachi omume nwere ike etinye obi gị dum site na ndị ọzọ nne na nna-ntọala, nke ahụ dabara onwe-akpata fission. Na ikpe nke uranium-238 atọ neutrons, nke na-ebilite na ume na-erughị 1 MeV (na ike na fission nke uranium isi - 158 MeV - ukwuu n'ime converted n'ime kinetic ume cleavage iberibe), ya mere, ha nwere ike ghara ime ka a n'ihu nkewa nke a nuclide. Otú ọ dị, ọ bụrụ na a ịrịba ịta nke obere isotope U ²³⁵ ndị a free neutrons nwere ike weghaara nuclei nke ²³⁵ U, ọ pụrụ n'ezie ime ka cleavage, ebe ọ bụ na nke a bụrụ na e nweghị ike fọrọ n'okpuru nke nkewa na-adịghị akpata.

Nke a bụ ụkpụrụ yinye mmeghachi omume.

Types of Nuclear Jeremaya mere

Ka k - ọnụ ọgụgụ nke neutrons emepụta a sample nke fissile ihe na nzọụkwụ n nke yinye, kewara ekewa site na ọnụ ọgụgụ nke neutrons emepụta ogbo n - 1. Nke a ọnụ ọgụgụ ga-adabere na ọnụ ọgụgụ nke neutrons emepụta nzọụkwụ n - 1, na-etinye obi gị dum site na isi, nke nwere ike na-ata rata fission.

• Ọ bụrụ na k <1 on, ogologo mmeghachi omume bụ nanị n'ihi uzuoku na usoro ga-akwụsị nnọọ ngwa ngwa. Nke a bụ ihe na-eme na eke na uranium ore, na nke ịta ^{nke 235} U dị nnọọ nta nke ndị gbasara nke puru omume absorption nke a neutron a isotope bụ nnọọ negligible.

• Ọ bụrụ na k> 1, ogologo mmeghachi omume ga-anọgide na-eto eto dị ka ogologo oge niile nke fissile ihe onwunwe agaghị eji (na atọm bọmbụ). Nke a na-enweta site ọgaranya eke ore nweta a zuru ezu elu ịta nke uranium-235. N'ihi * Tụkwasị sample uru k-abawanye na ihe gbasara nke puru nke neutron absorption, nke bụ dabere na na okirikiri nke okirikiri. Ya mere U ibu ga-gafere a ụfọdụ oké egwu uka na fission nke uranium (ihe mkpalite) nwere ike ime.

• Ọ bụrụ na k = 1 ahụ, e nwere a na-achịkwa mmeghachi omume. Ọ na-eji na nuclear ngwa agha. The usoro a na-achịkwa nkesa n'etiti uranium nkpa-n'aka nke cadmium ma ọ bụ boron, nke banye kasị nke neutrons (a ọcha bụ ike nke na-akada neutrons). Nkerisi uranium cores ọ na-akpaghị aka na-achịkwa na-akpụ akpụ na mkpanaka nke na k uru anọgide hà otu.