Qhov txawv ntawm Uranium 234 235 thiab 238 yog Uranium 234 muaj 142 neutrons thiab Uranium 235 muaj 143 neutrons, whereas Uranium 238 muaj 146 neutrons.
Uranium yog hlau hnyav. Nws yog ib qho chaw muaj zog uas tau siv rau txog 60 xyoo. Nws muab cov roj nuclear rau kev tsim hluav taws xob. Uranium hlau muaj ntau cov isotopes nyob ntawm seb muaj pes tsawg tus neutrons hauv lawv cov atomic nuclei.
Uranium 234 yog dab tsi?
Uranium 234 yog ib qho isotope ntawm Uranium hnyav hlau, muaj 95 protons thiab 142 neutrons hauv atomic nucleus. Peb tuaj yeem pom qhov isotope no yog 234U. Nws yog ib qho tsis tshua muaj isotope uas muaj ntau yam ntuj tso ntawm ib ncig ntawm 0.0054%. Qhov no yog vim nws ib nrab-lub neej (246 000 xyoo) yog hais txog 1/18 000 ntawm Uranium 238 isotope. Yog li ntawd, peb tuaj yeem soj ntsuam uranium 234 hauv uranium ores ua cov khoom lwj ntawm uranium 238.
Txoj hauv kev tseem ceeb ntawm kev tsim cov uranium 234 yog los ntawm kev puas tsuaj hauv nuclear, uas suav nrog uranium 238 (niam txiv isotope ntawm uranium 234) emitting ib qho alpha particle, ua rau thorium 234 tom qab thorium 234 (muaj ib nrab-lub neej luv). emitting ib tug beta particle los tsim protactinium 234, uas ces zoo li emit lwm beta particle ua uranium 234 nuclei.
Peb tuaj yeem cais cov uranium 234 los ntawm txoj kev sib cais isotope lossis los ntawm txoj kev ua kom cov uranium ntxiv, tab sis tsis muaj qhov xav tau txaus rau cov isotope hauv chemistry, physics lossis engineering.
Apart from that, uranium 234 has a neutron-capture cross-section that is about 100 barns for thermal neutrons and about 700 barns for the resonance integral (qhov nruab nrab neutrons muaj ntau yam ntawm nruab nrab energies). Thaum peb siv uranium 234 hauv lub tshuab hluav taws xob nuclear, peb tuaj yeem pom tias ob qho tib si uranium 234 thiab 238 nyiam ntes cov neutron, tom qab ntawd hloov mus rau hauv uranium 235 thiab plutonium 239, raws li. Kev hloov pauv ntawm uranium 234 mus rau uranium 235 tshwm sim ntawm tus nqi ntau dua li kev hloov pauv ntawm uranium 238 rau plutonium 239.
Uranium 235 yog dab tsi?
Uranium 235 yog ib qho isotope ntawm uranium hnyav hlau, muaj 92 protons thiab 143 neutrons. Thaum xav txog nws qhov kev nplua nuj, nws yog li 0.72% ua rau nws muaj ntau dua li uranium 234. Qhov isotope no yog fissile, thiab nws tuaj yeem txhawb nqa cov fission chain reaction. Ntxiv mus, qhov no tsuas yog fissile isotope uas tshwm sim raws li ib tug primordial nuclide.
Lub neej ib nrab ntawm cov isotope no yog kwv yees li 703.8 lab xyoo. Cov tshuaj no tau pom los ntawm Arthur Jeffery Dempster hauv xyoo 1935. Tsis tas li ntawd, lub fission cross-section rau qeeb thermal neutrons yog hais txog 585 barns, thiab rau ceev neutrons, nws yog hais txog 1 barn. Feem ntau, yuav luag tag nrho cov neutron absorptions ntawm no isotope ua rau fission, thiab ib tug tsawg ntawm nws tshwm sim nyob rau hauv neutron capturing, uas tsim uranium 236.
Uranium 238 yog dab tsi?
Uranium 238 yog ib qho isotope ntawm uranium, muaj 92 protons thiab 146 neutrons hauv atomic nuclei. Nws yog cov isotope tshaj plaws ntawm uranium uas tshwm sim hauv qhov xwm txheej. Tus txheeb ze abundance yog hais txog 99%. Qhov no isotope ntawm uranium tsis fissile. Yog li, nws tsis tuaj yeem txhawb nqa cov tshuaj tiv thaiv kab mob hauv lub thermal-neutron reactor.
Txawm li cas los xij, uranium 238 tuaj yeem raug fissionable los ntawm cov neutrons ceev. Yog vim li cas vim li cas uranium 238 tsis tuaj yeem txhawb nqa cov tshuaj tiv thaiv kab mob yog tias inelastic tawg ua rau txo qis neutron zog qhov twg muaj qhov tshwm sim ib los yog ntau dua tiam tom ntej nuclei.
Qhov txawv ntawm Uranium 234 235 thiab 238 yog dab tsi?
Uranium hlau muaj ntau cov isotopes nyob ntawm seb muaj pes tsawg tus neutrons hauv lawv cov atomic nuclei. Qhov sib txawv tseem ceeb ntawm Uranium 234 235 thiab 238 yog Uranium 234 muaj 142 neutrons thiab Uranium 235 muaj 143 neutrons, whereas Uranium 238 muaj 146 neutrons.
Hauv qab no yog cov npe sib txawv ntawm Uranium 234 235 thiab 238 hauv daim ntawv teev npe.
Summary – Uranium 234 vs 235 vs 238
Uranium yog ib qho tseem ceeb ntawm lub zog siv nyob rau hauv nuclear reactors rau tsim hluav taws xob. Muaj ntau ntau yam isotopes ntawm uranium hlau, uas txawv ntawm ib leeg raws li tus naj npawb ntawm neutrons tam sim no nyob rau hauv lawv atomic nuclei. Qhov sib txawv tseem ceeb ntawm Uranium 234 235 thiab 238 yog Uranium 234 muaj 142 neutrons thiab Uranium 235 muaj 143 neutrons, whereas Uranium 238 muaj 146 neutrons.
