Cov ntaub ntawv tshiab kawg: Kev siv cov hmoov graphite hauv kev sim nuclear

Qhov kev puas tsuaj ntawm cov hluav taws xob ntawm cov hmoov graphite muaj qhov cuam tshuam loj heev rau kev ua haujlwm thiab kev lag luam ntawm lub reactor, tshwj xeeb tshaj yog lub txaj zeb kub siab roj-txias reactor. Lub tshuab ntawm neutron moderation yog qhov elastic scattering ntawm neutrons thiab cov atoms ntawm cov khoom moderating, thiab lub zog nqa los ntawm lawv raug xa mus rau cov atoms ntawm cov khoom moderating. Graphite hmoov kuj yog tus neeg sib tw cog lus rau cov khoom siv plasma-oriented rau nuclear fusion reactors. Cov neeg kho hauv qab no los ntawm Fu Ruite qhia txog kev siv cov hmoov graphite hauv kev sim nuclear:

Nrog rau qhov nce ntawm neutron fluence, cov hmoov graphite ua ntej yuav ntsws, thiab tom qab ncav cuag tus nqi me me, qhov ntsws yuav txo qis, rov qab mus rau qhov loj me qub, thiab tom qab ntawd nthuav dav sai sai. Yuav kom siv tau cov neutrons uas tso tawm los ntawm fission, lawv yuav tsum tau qeeb qeeb. Cov khoom siv thermal ntawm cov hmoov graphite tau los ntawm kev sim irradiation, thiab cov xwm txheej xeem irradiation yuav tsum zoo ib yam li cov xwm txheej ua haujlwm tiag tiag ntawm lub reactor. Lwm txoj kev ntsuas los txhim kho kev siv cov neutrons yog siv cov ntaub ntawv reflective los cuam tshuam cov neutrons uas tawm ntawm thaj chaw fission reaction zone-core rov qab. Lub mechanism ntawm neutron reflection kuj yog qhov elastic scattering ntawm neutrons thiab atoms ntawm cov ntaub ntawv reflective. Yuav kom tswj tau qhov poob los ntawm cov khoom tsis huv mus rau qib uas tso cai, cov hmoov graphite siv hauv lub reactor yuav tsum yog nuclear pure.

Hmoov graphite nuclear yog ib ceg ntawm cov khoom siv hmoov graphite uas tau tsim los teb rau qhov xav tau ntawm kev tsim cov reactor fission nuclear thaum ntxov xyoo 1940. Nws yog siv ua moderator, reflection thiab cov ntaub ntawv qauv hauv cov reactors tsim khoom, cov reactors txias roj thiab cov reactors txias roj kub siab. Qhov feem pua ​​ntawm neutron reacting nrog lub nucleus hu ua cross section, thiab thermal neutron (nruab nrab zog ntawm 0.025 eV) fission cross section ntawm U-235 yog ob qib siab dua li fission neutron (nruab nrab zog ntawm 2 eV) fission cross section. Cov elastic modulus, lub zog thiab linear expansion coefficient ntawm hmoov graphite nce nrog kev nce ntawm neutron fluence, ncav cuag tus nqi loj, thiab tom qab ntawd txo qis sai. Thaum ntxov xyoo 1940, tsuas yog hmoov graphite muaj nyob rau ntawm tus nqi pheej yig ze rau qhov purity no, yog vim li cas txhua lub reactor thiab cov reactors tsim khoom tom qab siv hmoov graphite ua cov khoom siv moderating, coj mus rau hauv lub hnub nyoog nuclear.

Tus yuam sij rau kev ua cov hmoov graphite isotropic yog siv cov coke uas muaj isotropy zoo: isotropic coke lossis macro-isotropic secondary coke ua los ntawm anisotropic coke, thiab cov thev naus laus zis coke secondary feem ntau siv tam sim no. Qhov loj ntawm kev puas tsuaj los ntawm hluav taws xob cuam tshuam nrog cov khoom siv raw ntawm graphite hmoov, cov txheej txheem tsim khoom, kev hloov pauv sai ntawm neutron thiab tus nqi hloov pauv, qhov kub thiab txias irradiation thiab lwm yam. Qhov sib npaug ntawm boron ntawm nuclear graphite hmoov yuav tsum nyob ib puag ncig 10 ~ 6.