Fission na uranium nuclei. Sarkar dauki. Description of aiwatar

Rarraba core - wani nauyi zarra tsagawa cikin biyu, niƙaƙƙun gaɓãɓuwa kusan daidai nauyi, bi da 'yanci na babban adadin kuzari.

A gano makaman nukiliya fission farkon wani sabon zamanin - "atomic shekaru". Da m na ta yiwu amfani da ma'auni na hadarin amfana daga ta amfani, ba kawai ya ba Yunƙurin zuwa wani yawa sociological, siyasa, tattalin arziki da kuma kimiyya nasarori, amma kuma wata babbar matsala. Ko daga zalla kimiyya ra'ayi, da makaman nukiliya fission aiwatar halitta babban adadin wasanin gwada ilimi da kuma rikitarwa, kuma mai cikakken msar tambayar bayani ga shi, wani abu ne na gaba.

Sharing - m

dauri makamashi (da nucleon) ya bambanta a daban-daban nuclei. Mutum da ƙananan nauyin makamashi fiye da located in tsakiyar lokaci-lokaci tebur.

Wannan yana nufin cewa nauyi nuclei a cikin abin da atomic yawan fi 100, advantageously kasu kashi biyu karami, niƙaƙƙun gaɓãɓuwa, game da shi sakewa makamashi da cewa an tuba zuwa sanadin motsi makamashi na da wani ɓaɓɓake. Wannan tsari shine ake kira tsagawa atomic tsakiya.

A daidai da kwanciyar hankali kwana, wanda ya nuna da dogaro da yawan protons ne daga barga nuclides for neutron mutum tsakiya fi son wani ya fi girma yawan neutrons (idan aka kwatanta da yawan protons) fiye da m. Wannan ya nuna cewa, a Bugu da kari ga tsagawa tsari za a jefarwa wasu "kayayyakin" neutrons. Bugu da kari, su ma za su dauki kan wasu daga cikin makamashi sake. Nazarin fission na uranium kwayoyin halitta ya nuna cewa wannan ya haifar da wani neutron 3-4: U → ^{238 145 90} La + Br + 3n.

A atomic lamba (da atomic taro) na gutsure ba daidai yake da rabin da atomic taro na iyaye. Bambanci tsakanin talakawa da kwayoyin halitta kafa a sakamakon tsakiyan nonon ne yawanci game da 50. Duk da haka, dalilin haka shi ne ba tukuna, gabã ɗaya, bayyananne.

Daure kuzari na ²³⁸ U, ¹⁴⁵ La Br da ⁹⁰ ne 1803, 1198 da kuma 763 MeV bi da bi. Wannan yana nufin cewa makamashi da aka saki uranium fission daidai 1198 + 158 = 763-1803 MeV sakamakon da dauki.

maras wata-wata fission

maras wata-wata tsagawa tafiyar matakai an sani a cikin yanayi, amma su ne sosai rare. A talakawan rayuwa na wannan tsari ne game da 10 ^17, da kuma, alal misali, da talakawan rayuwa na alpha-lalata da radionuclide ne game da 10 ^11.

Dalilin wannan shi ne cewa domin ya ware kashi biyu, da zuciyar dole ne da farko sha nakasawa (mikewa) a cikin wani ellipsoidal form, sa'an nan, kafin karshe tsakiyan nonon zuwa cikin biyu, niƙaƙƙun gaɓãɓuwa samar da wata "wuyansa" a tsakiyar.

m shãmaki

A maras kyau jiha a core na biyu sojojin. Daya daga cikinsu - da ya karu surface makamashi (surface tashin hankali na ruwa droplets bayyana ta siffar zobe siffar), da kuma sauran - da Coulomb tunkuxe tsakanin fission, niƙaƙƙun gaɓãɓuwa. Tare da suke samar da m shãmaki.

Kamar yadda a yanayin saukan alpha lalata faruwa kwatsam fission na uranium atomic nuclei, da, niƙaƙƙun gaɓãɓuwa dole shawo kan wannan shãmaki ta wajen jimla ta murhu. A shamaki ne game da 6 MeV, kamar yadda a cikin hali na alpha-lalace, amma yiwuwar murhu na α-barbashi ne da yawa fiye da da yawa wa mutum samfurin tsagawa zarra.

tilasta ƙasƙanci

Yawa mafi kusantar da aka jawo fission na uranium nuclei. A wannan yanayin, iyaye tsakiya ne irradiated tare da neutrons. Idan iyaye shi garwaya, sa'an nan suka daure su saki da dauri da makamashi a cikin nau'i na vibrational makamashi da cewa zai iya wuce 6 MeV bukatar cin nasara da m shãmaki.

Ina ƙarin neutron makamashi bai isa ya shawo kan yuwuwar shãmaki, da ya faru neutron dole ne a mafi ƙarancin sanadin motsi makamashi domin su iya sa tsagawa na zarra. A cikin hali na ²³⁸ U ƙarin neutron nauyin makamashi ne m game da 1 MeV. Wannan yana nufin cewa fission na uranium nuclei jawo kawai neutrons tare da wani sanadin motsi makamashi mafi girma daga 1 MeV. A daya hannun, da ²³⁵ U isotope yana daya unpaired neutron. Lokacin da wani tsakiya garwaya da ƙarin, shi Forms tare da shi kamar wata da wani ƙarin nauyin makamashi ne a sakamakon wannan hadi. Wannan shi ya isa ga saki da adadin makamashin da ake bukata don cin nasara da m shãmaki na tsakiya da kuma na ƙungiyar isotopes faru a wani karo da wani neutron.

beta lalata

Duk da cewa da fission dauki ake jefarwa ta uku ko hudu neutrons, niƙaƙƙun gaɓãɓuwa har yanzu dauke mafi neutrons fiye da su barga isobars. Wannan yana nufin cewa tsakiyan nonon da wani ɓaɓɓake ne kullum m game da beta lalace.

Alal misali, lokacin da akwai wani rabo daga cikin nucleus din uranium ²³⁸ U, barga isobars da A = 145 ¹⁴⁵ ne neodymium ND, wanda ke nufin cewa gutsure lanthanum La ¹⁴⁵ tsãgewar ƙwãyar cikin matakai uku, kowane lokaci ta haskakawa electron da wani neutrino har a barga nuclide aka kafa. Barga isobars da A = 90 ⁹⁰ ne zirconium ZR, don haka tsakiyan nonon gutsure bromo Br ⁹⁰ tsãgewar ƙwãyar cikin biyar, saukarwa sarkar β-lalace.

Wadannan sarkar β-lalace emit karin makamashi wanda aka kwashe kusan duk na electron da wani neutrino.

Nukiliya halayen: fission na uranium

Direct nuclide daga neutron radiation da ma manyan yawan su tabbatar da zaman lafiyar na tsakiya ne mai wuya. Ga batu ne da cewa babu wani Coulomb tunkuxe, kuma haka surface makamashi o ƙarin riƙe da neutron saboda da iyaye. Duk da haka, wani lokacin da ya faru. Alal misali, fission gutsure Br ⁹⁰ a farko beta-lalace samar da wani krypton-90, wanda za a iya located in wani m jihar tare da isasshen makamashi da shawo kan surface makamashi. A wannan yanayin da neutron radiation iya faruwa kai tsaye ta samar da wata krypton-89. Wannan isobars ne har yanzu m game da beta-lalace ya ba tukuna tafi a cikin barga yttrium-89, don haka da cewa krypton-89 ne zuwa kashi uku, saukarwa.

Uranium fission: Sarkar Reaction

Neutrons jefarwa a tsakiyan nonon dauki za a iya tunawa da wasu iyaye-tsakiya, wanda sa'an nan shigarsu kai-jawo fission. A cikin hali na uranium-238 uku neutrons, wanda bayyana fita da kuzari kasa da 1 MeV (da makamashi sake a fission na uranium core - 158 MeV - kagaggun tuba zuwa sanadin motsi makamashi tsakiyan nonon da wani ɓaɓɓake), don haka ba za su iya haifar da wani m division wannan nuclide. Duk da haka, idan wani gagarumin taro na rare isotope U ²³⁵ wadannan free neutrons za a iya kama da nuclei na ²³⁵ U, shi iya zahiri sa tsakiyan nonon, tun a cikin wannan harka akwai wani makamashi dokin kasa da rabon da aka ba jawo.

Wannan ne manufa sarkar dauki.

Nau'in na nukiliya halayen

Bari k - yawan neutrons samar a cikin wani samfurin na fissile abu a mataki n na sarkar, raba da adadin na neutrons samar a mataki n - 1. Wannan lambar zai dogara ne a kan yawan neutrons samar a mataki n - 1, ana tunawa da core, wanda iya sha jawo fission.

• Idan k <1 a, da sarkar dauki kawai daga tururi da kuma tsari zai daina sosai da sauri. Wannan shi ne abin da ya faru a cikin halitta uranium tama, a cikin abin da taro ^{na 235} U ne don haka kananan cewa yiwuwar samun sha na wani neutron wannan isotope ne musamman negligible.

• Idan k> 1, da sarkar dauki zai ci gaba da girma kamar yadda dai duk da fissile abu ba za a yi amfani da (da atomic bam). Wannan aka samu da enriching halitta tama su sami wani isasshe babban taro na uranium-235. Domin siffar zobe samfurin darajar k ƙaruwa tare da yiwuwar neutron sha, wanda shi ne dogara a kan radius daga cikin Sphere. Saboda haka U nauyi dole wuce wani m taro don fission na uranium (sarkar dauki) iya faruwa.

• Idan k = 1, to, akwai a sarrafawa dauki. Ana amfani da makaman nukiliya nukiliya. A tsari ne sarrafawa rarraba tsakanin uranium dũka na cadmium ko boron, wanda sha mafi yawan neutrons (wadannan abubuwa ne iya kamawa neutrons). Rarraba uranium tsakiya shi ne ta atomatik sarrafawa da motsi da sanda saboda haka cewa k darajar zauna daidai to daya.