304L 6.35 * 1mm Bakin Karfe naɗaɗɗen tubing masu kaya, Nunawa wani matsanancin lithium katako don samar da pulsed kai tsaye neutrons

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A matsayin madadin binciken injinan nukiliya, ƙaramin janareta mai haɓakawa na neutron janareta ta amfani da direban katako na lithium-ion na iya zama ɗan takara mai ban sha'awa saboda yana haifar da ƙarancin hasken da ba a so.Koyaya, yana da wahala a isar da babban katako na ion lithium, kuma ana ɗaukar aikace-aikacen irin waɗannan na'urori ba zai yiwu ba.An magance mafi tsananin matsalar rashin isassun kwararar ion ta hanyar amfani da tsarin dasa plasma kai tsaye.A cikin wannan makirci, babban ɗigon jini mai ɗimbin yawa wanda aka samar ta hanyar cirewar laser na foil ɗin ƙarfe na lithium ana yin allurar da kyau kuma yana haɓaka ta babban mai saurin mitar quadrupole (RFQ accelerator).Mun sami mafi girman katako na yanzu na 35 mA wanda aka haɓaka zuwa 1.43 MeV, wanda shine umarni biyu na girma sama da injector na al'ada da tsarin haɓakawa na iya samarwa.
Ba kamar haskoki na X-ray ko abubuwan da aka caje ba, neutrons suna da zurfin shigar ciki mai girma da mu'amala ta musamman tare da ma'auni, yana mai da su musamman bincike don nazarin kaddarorin kayan1,2,3,4,5,6,7.Musamman, ana amfani da dabarun watsawa na neutron don nazarin abubuwan da ke ciki, tsari, da damuwa na ciki a cikin nau'i mai mahimmanci kuma zai iya ba da cikakken bayani game da abubuwan da aka gano a cikin ƙananan ƙarfe waɗanda ke da wuyar ganewa ta amfani da X-ray spectroscopy8.Ana ɗaukar wannan hanya a matsayin kayan aiki mai ƙarfi a cikin ilimin kimiyya na asali kuma masu kera karafa da sauran kayan ke amfani da su.Kwanan nan, an yi amfani da diffraction na neutron don gano saura damuwa a cikin kayan aikin injiniya kamar sassan jirgin ƙasa da jirgin sama9,10,11,12.Hakanan ana amfani da Neutron a rijiyoyin mai da iskar gas saboda ana samun sauƙin kama su ta hanyar abubuwan da ke da wadatar proton13.Hakanan ana amfani da irin wannan hanyoyin a aikin injiniyan farar hula.Gwajin neutron mara lalacewa shine ingantaccen kayan aiki don gano ɓoyayyun kurakuran gine-gine, tunnels da gadoji.Ana amfani da amfani da katako na neutron sosai a cikin bincike na kimiyya da masana'antu, yawancin su a tarihi an haɓaka su ta hanyar amfani da makamashin nukiliya.
Duk da haka, tare da yarjejeniya ta duniya game da hana yaduwar makaman nukiliya, gina ƙananan injiniyoyi don dalilai na bincike yana ƙara zama mai wahala.Haka kuma, hatsarin Fukushima na baya-bayan nan ya sanya gina ma'aunin makamashin nukiliya kusan karbuwa a tsakanin al'umma.Dangane da wannan yanayin, buƙatar tushen neutron a accelerators yana haɓaka2.A matsayin madadin na'urori masu sarrafa makamashin nukiliya, manyan maɓuɓɓugan neutron da yawa masu haɓakawa sun riga sun fara aiki14,15.Duk da haka, don ingantaccen amfani da kaddarorin neutron katako, ya zama dole don fadada amfani da ƙananan tushe a masu haɓakawa, 16 wanda zai iya kasancewa na cibiyoyin bincike na masana'antu da jami'a.Maɓuɓɓugan neutron mai haɓakawa sun ƙara sabbin ƙarfi da ayyuka ban da yin aiki a matsayin maye gurbin ma'aikatan makamashin nukiliya14.Misali, janareta mai sarrafa linac yana iya ƙirƙirar rafin neutron cikin sauƙi ta hanyar sarrafa katakon tuƙi.Da zarar an fitar da shi, neutrons yana da wahalar sarrafawa kuma ma'aunin radiation yana da wuyar tantancewa saboda hayaniyar neutrons na baya.Neutrons da aka zazzage wanda na'ura mai sauri ke sarrafawa ta guje wa wannan matsalar.An gabatar da ayyuka da yawa dangane da fasahar haɓakar proton a duk duniya17,18,19.Halayen 7Li(p, n)7Be da 9Be(p,n)9B ana yawan amfani dasu a cikin ƙaramin injin neutron da ke motsa proton saboda halayen endothermic ne20.Za'a iya rage yawan radiyo da sharar rediyo idan makamashin da aka zaɓa don tada da katako na proton ya ɗan yi sama da ƙimar kofa.Duk da haka, yawan ƙwayar ƙwayar da aka yi niyya ya fi girma fiye da na protons, kuma sakamakon neutrons ya watse a kowane bangare.Irin wannan kusa da fitar da istiropic na iskar neutron yana hana ingantaccen jigilar neutron zuwa abin nazari.Bugu da ƙari, don samun adadin da ake buƙata na neutrons a wurin da abin yake, yana da muhimmanci don ƙara yawan adadin protons masu motsi da makamashi.A sakamakon haka, manyan allurai na gamma haskoki da neutrons za su yadu ta manyan kusurwoyi, suna lalata fa'idar halayen endothermic.Na'urar inzara mai ƙarfi mai ƙarfi mai ƙarfi na tushen neutron janareta yana da ƙarfin garkuwar radiation kuma shine mafi girman ɓangaren tsarin.Bukatar ƙara ƙarfin protons na tuƙi yawanci yana buƙatar ƙarin haɓaka girman kayan aikin totur.
Don shawo kan gazawar gabaɗaya na ƙaƙƙarfan tushen neutron na al'ada a accelerators, an gabatar da wani tsarin amsawa-kinematic inversion21.A cikin wannan makirci, ana amfani da katako mai nauyi na lithium-ion azaman jagorar katako maimakon katako na proton, wanda ake nufi da abubuwan da ke da wadatar hydrogen kamar su robobin hydrocarbon, hydrides, hydrogen gas, ko plasma hydrogen.An yi la'akari da wasu zaɓuɓɓuka, irin su beryllium ion beams, duk da haka, beryllium abu ne mai guba wanda ke buƙatar kulawa ta musamman wajen sarrafawa.Sabili da haka, katako na lithium shine mafi dacewa da tsarin inversion-kinematic dauki.Tunda lokacin da sinadarin lithium nuclei ya fi na protons girma, cibiyar hada-hadar makaman nukiliya ta ci gaba da tafiya kullum, haka nan neutron kuma ke fitar da gaba.Wannan fasalin yana kawar da haskoki gamma maras so da hayaƙin neutron mai girman kusurwa22.Ana nuna kwatancen yanayin da aka saba na injin proton da yanayin yanayin kinematics mai juzu'i a cikin hoto 1.
Misalin kusurwar samar da neutron don proton da katako na lithium (wanda aka zana tare da Adobe Illustrator CS5, 15.1.0, https://www.adobe.com/products/illustrator.html).(a) Ana iya fitar da Neutrons ta kowace hanya a sakamakon abin da ya faru saboda gaskiyar cewa protons masu motsi sun buga mafi nauyi atom na maƙasudin lithium.(b) Akasin haka, idan direban lithium-ion ya jefa bama-bamai akan manufa mai wadatar hydrogen, ana samar da neutrons a cikin kunkuntar mazugi a gaban gaba saboda tsananin saurin tsakiyar tsarin.
Koyaya, ƴan inversel kinematic neutron janareta ne kawai ke wanzu saboda wahalar samar da buƙatun da ake buƙata na ions masu nauyi tare da babban caji idan aka kwatanta da protons.Duk waɗannan tsire-tsire suna amfani da tushen ion mara kyau a hade tare da tandem electrostatic accelerators.An ba da shawarar wasu nau'ikan tushen ion don haɓaka haɓakar haɓakar katako26.A kowane hali, ƙarfin lithium-ion katako na yanzu yana iyakance zuwa 100 µA.An ba da shawarar yin amfani da 1 mA na Li3+27, amma wannan yanayin ba a tabbatar da shi ta wannan hanyar ba.Dangane da ƙarfi, masu haɓaka katako na lithium ba za su iya yin gasa tare da na'urori masu ƙara kuzari waɗanda kololuwar proton ɗin su ya wuce 10 mA28.
Don aiwatar da ingantacciyar janareta na neutron mai amfani bisa tushen lithium-ion katako, yana da fa'ida don samar da babban ƙarfi gaba ɗaya ba tare da ions ba.Ƙungiyoyin lantarki na lantarki suna haɓaka da ions ions, kuma mafi girman matakin caji yana haifar da ingantaccen hanzari.Direbobin katako na Li-ion suna buƙatar mafi girman igiyoyin Li3+ fiye da 10mA.
A cikin wannan aikin, muna nuna haɓakar katako na Li3 + tare da kololuwar igiyoyi har zuwa 35 mA, wanda yayi daidai da na'urori masu haɓaka proton.Asalin lithium ion katako an ƙirƙira shi ta amfani da ablation na Laser da Tsarin Tsarin Tsarin Plasma kai tsaye (DPIS) wanda aka ƙirƙira da farko don haɓaka C6+.An ƙirƙira ƙirar mitar rediyo ta al'ada (RFQ linac) ta amfani da tsarin resonant mai sanda huɗu.Mun tabbatar da cewa katako mai hanzari yana da ƙididdige yawan ƙarfin katako mai tsabta.Da zarar an kama katako na Li3 + da kyau da haɓaka ta hanyar mai haɓaka mitar rediyo (RF), ana amfani da sashin linac na gaba (accelerator) don samar da makamashin da ake buƙata don samar da kwararar neutron mai ƙarfi daga manufa.
Haɓaka haɓakar ions mai girma shine ingantaccen fasaha.Sauran aikin da ya rage na gane sabon ingantacciyar ingantacciyar janareta na neutron shine samar da adadi mai yawa na ion lithium da aka cire gaba daya da samar da tsarin tari mai kunshe da jerin gwanon ion wanda aka daidaita tare da zagayowar RF a cikin mai kara kuzari.An bayyana sakamakon gwaje-gwajen da aka tsara don cimma wannan buri a cikin sassa uku masu zuwa: (1) ƙarni na gaba ɗaya wanda ba shi da katako na lithium-ion, (2) haɓakar katako ta amfani da linac na musamman na RFQ, da (3) haɓaka bincike. na katako don duba abinda ke ciki.A Brookhaven National Laboratory (BNL), mun gina saitin gwaji da aka nuna a Hoto 2.
Bayyani na saitin gwaji don saurin bincike na katako na lithium (wanda Inkscape ya kwatanta, 1.0.2, https://inkscape.org/).Daga dama zuwa hagu, Laser-ablative plasma ana samar da shi a cikin ɗakin hulɗar Laser-manufa kuma an kai shi ga linac RFQ.Bayan shigar da abin totur na RFQ, ana raba ions daga plasma kuma ana allura su cikin injin RFQ ta hanyar wutar lantarki kwatsam da aka ƙirƙira ta hanyar 52kV na ƙarfin lantarki tsakanin injin cirewa da na'urar lantarki ta RFQ a cikin yankin drift.Ana haɓaka ions da aka fitar daga 22 keV/n zuwa 204 keV/n ta amfani da na'urorin RFQ masu tsayin mita 2.A halin yanzu mai canzawa (CT) shigar a wurin fitarwa na RFQ linac yana ba da ma'aunin mara lalacewa na ion beam current.An mai da hankali kan katako ta hanyar maganadisu quadrupole guda uku kuma an tura shi zuwa magnet dipole, wanda ke raba kuma yana jagorantar katakon Li3+ cikin na'urar ganowa.Bayan tsagewar, ana amfani da scintillator na filastik mai jujjuyawa da kofin Faraday (FC) tare da son zuciya har zuwa -400 V ana amfani da su don gano katako mai haɓakawa.
Don samar da cikakken ionized lithium ions (Li3+), ya zama dole don ƙirƙirar plasma tare da zazzabi sama da ƙarfin ionization na uku (122.4 eV).Mun yi ƙoƙarin yin amfani da ablation na laser don samar da plasma mai zafi.Ba a saba amfani da wannan nau'in tushen ion na Laser don samar da katako na lithium ion ba saboda ƙarfe na lithium yana amsawa kuma yana buƙatar kulawa ta musamman.Mun ƙirƙiri tsarin lodin da aka yi niyya don rage danshi da gurɓataccen iska lokacin shigar da foil na lithium a cikin ɗakin hulɗar injin laser.An gudanar da duk shirye-shiryen kayan aiki a cikin yanayi mai sarrafawa na bushe argon.Bayan da aka shigar da foil ɗin lithium a ɗakin da aka yi niyya na Laser, an kunna foil ɗin tare da ƙwanƙwasa Nd: YAG Laser radiation a ƙarfin 800 mJ kowace bugun jini.A mayar da hankali kan abin da aka yi niyya, ana ƙididdige yawan ƙarfin laser kusan 1012 W/cm2.Ana ƙirƙira Plasma lokacin da Laser mai bugun jini ya lalata manufa a cikin sarari.A lokacin duka 6 ns Laser bugun jini, da plasma ya ci gaba da zafi sama, yafi saboda da baya tsarin bremsstrahlung.Tunda ba a yi amfani da filin waje mai iyaka ba yayin lokacin dumama, plasma ta fara faɗaɗa cikin girma uku.Lokacin da plasma ta fara faɗaɗa saman abin da ake niyya, tsakiyar taro na plasma yana samun saurin kai tsaye zuwa saman da aka yi niyya tare da ƙarfin 600 eV/n.Bayan dumama, plasma ya ci gaba da motsawa a cikin hanyar axial daga manufa, yana fadada isotropically.
Kamar yadda aka nuna a Hoto na 2, plasma zubar da jini yana faɗaɗa cikin ƙarar injin da ke kewaye da kwandon ƙarfe tare da yuwuwar abin da aka sa a gaba.Don haka, plasma ɗin ta zazzage ta cikin yankin da ba shi da filin zuwa ga mai saurin RFQ.Ana amfani da filin maganadisu axial tsakanin ɗakin iska mai iska na Laser da linac na RFQ ta hanyar raunin naɗaɗɗen solenoid a kusa da ɗakin injin.Filin maganadisu na solenoid yana hana haɓakar radial na ɗigon jini don kiyaye babban adadin plasma yayin isarwa zuwa buɗewar RFQ.A gefe guda kuma, plasma na ci gaba da fadadawa a cikin jagorar axial yayin tuƙi, yana samar da plasma mai tsawo.Ana amfani da babban ƙarfin wutar lantarki akan jirgin ruwa mai ɗauke da plasma a gaban tashar fita a mashigar RFQ.An zaɓi ƙarfin wutar lantarki na son zuciya don samar da ƙimar allurar 7Li3+ da ake buƙata don ingantaccen hanzari ta linac RFQ.
Sakamakon zubar da jini ya ƙunshi ba kawai 7Li3+ ba, har ma da lithium a cikin wasu jahohin caji da abubuwa masu gurɓata, waɗanda ake jigilar su lokaci guda zuwa na'urar ƙarar layin RFQ.Kafin ingantattun gwaje-gwaje ta amfani da RFQ linac, an gudanar da bincike na lokacin jirgin sama na layi (TOF) don nazarin abun da ke ciki da rarraba makamashi na ions a cikin plasma.An yi bayanin saitin nazari dalla-dalla da rarrabawar halin caji a cikin sashin Hanyoyi.Binciken ya nuna cewa 7Li3 + ions sune manyan kwayoyin halitta, suna kimanin kimanin 54% na dukkanin kwayoyin halitta, kamar yadda aka nuna a cikin Fig. 3. Bisa ga bincike, 7Li3 + ion halin yanzu a wurin fitowar ion beam an kiyasta a 1.87 mA.A yayin gwaje-gwajen gaggawa, ana amfani da filin solenoid na 79mT zuwa plasma mai faɗaɗawa.Sakamakon haka, 7Li3+ na yanzu da aka samo daga plasma kuma an lura akan mai ganowa ya karu da kashi 30.
Rukunin ions a cikin plasma da aka samar da Laser da aka samu ta hanyar nazarin lokacin tashi.7Li1+ da 7Li2+ ions sun ƙunshi 5% da 25% na ion katako, bi da bi.Yankin da aka gano na ɓangarori na 6Li ya yarda da abun ciki na halitta na 6Li (7.6%) a cikin maƙasudin foil na lithium a cikin kuskuren gwaji.An sami ɗan gurɓataccen iskar oxygen (6.2%), galibi O1+ (2.1%) da O2+ (1.5%), wanda zai iya zama saboda iskar oxygen da ke saman maƙasudin foil ɗin lithium.
Kamar yadda aka ambata a baya, plasma lithium yana ɗimuwa a cikin yanki marar fili kafin shigar da linac RFQ.Shigar da linac na RFQ yana da ramin diamita na 6 mm a cikin kwandon karfe, kuma ƙarfin son rai shine 52 kV.Kodayake ƙarfin lantarki na RFQ yana canzawa da sauri ± 29 kV a 100 MHz, ƙarfin lantarki yana haifar da hanzarin axial saboda na'urorin haɓaka RFQ suna da matsakaicin yuwuwar sifili.Saboda ƙarfin wutar lantarki mai ƙarfi da aka samar a cikin tazarar 10 mm tsakanin buɗewa da gefen ɗigon lantarki na RFQ, ions plasma masu kyau kawai ana fitar da su daga plasma a budewa.A cikin tsarin isar da ion na al'ada, ana raba ions daga plasma ta filin lantarki a nesa mai nisa a gaban mai saurin RFQ sannan kuma a mai da hankali cikin buɗaɗɗen RFQ ta wani yanki mai mai da hankali kan katako.Koyaya, don tsananin ƙarfin ion ion da ake buƙata don tushen neutron mai ƙarfi, rundunonin da ba na layi ba saboda tasirin cajin sararin samaniya na iya haifar da hasara mai yawa a cikin tsarin jigilar ion, yana iyakance kololuwar halin yanzu wanda za'a iya haɓakawa.A cikin DPIS ɗinmu, ana ɗaukar ions masu ƙarfi a matsayin plasma mai zurfafa kai tsaye zuwa wurin fita na buɗaɗɗen RFQ, don haka babu asarar ion katako saboda cajin sarari.A yayin wannan zanga-zangar, an yi amfani da DPIS a kan katako na lithium-ion a karon farko.
An ɓullo da tsarin RFQ don mai da hankali da haɓaka ƙananan ƙarfin ƙarfin ion katako na yanzu kuma ya zama ma'auni don haɓaka oda na farko.Mun yi amfani da RFQ don haɓaka 7Li3 + ions daga makamashin da aka saka na 22 keV / n zuwa 204 keV / n.Kodayake lithium da sauran barbashi tare da ƙaramin caji a cikin plasma kuma ana fitar da su daga plasma kuma ana allurar su cikin buɗaɗɗen RFQ, linac na RFQ yana haɓaka ions kawai tare da ƙimar caji-zuwa-mass (Q/A) kusa da 7Li3+.
A kan fig.Hoto na 4 yana nuna nau'ikan raƙuman raƙuman ruwa da aka gano ta hanyar mai canzawa (CT) a fitarwa na RFQ linac da Kofin Faraday (FC) bayan nazarin maganadisu, kamar yadda aka nuna a fig.2. Ana iya fassara canjin lokaci tsakanin sigina a matsayin bambancin lokacin tashi a wurin mai ganowa.Mafi girman ion na yanzu da aka auna a CT shine 43mA.A matsayin RT, katako mai rijista na iya ƙunsar ba kawai ions da aka haɓaka zuwa makamashin da aka ƙididdigewa ba, har ma da ions ban da 7Li3 +, waɗanda ba su da haɓaka sosai.Koyaya, kamanni na nau'ikan ion na yanzu da aka samo ta hanyar QD da PC yana nuna cewa ion na yanzu ya ƙunshi haɓakar 7Li3+, kuma raguwar ƙimar ƙimar na yanzu akan PC yana haifar da asarar katako yayin canja wurin ion tsakanin QD da PC.Hasara Wannan kuma yana tabbatar da kwaikwaiyon ambulaf.Don auna daidai 7Li3+ katako na yanzu, ana nazarin katako tare da magnet dipole kamar yadda aka bayyana a sashe na gaba.
Oscillograms na ƙarar katako da aka rubuta a cikin wuraren ganowa CT (black curve) da FC (karfin ja).Wadannan ma'aunai suna haifar da su ta hanyar gano hasken laser ta hanyar mai daukar hoto yayin samar da plasma na Laser.Baƙaƙen lanƙwan yana nuna nau'in igiyar ruwa da aka auna akan CT da aka haɗa da kayan aikin linac na RFQ.Saboda kusancinsa da linac na RFQ, mai ganowa yana ɗaukar hayaniya 100 MHz RF, don haka an yi amfani da matatar FFT mai ƙarancin 98 MHz don cire siginar RF mai resonant na 100 MHz wanda aka mamaye kan siginar ganowa.Madaidaicin ja yana nuna sifar igiyar ruwa a FC bayan magnetin nazari yana jagorantar katakon 7Li3+ ion.A cikin wannan filin maganadisu, baya ga 7Li3+, N6+ da O7+ ana iya jigilar su.
Hasken ion bayan linac na RFQ yana mai da hankali ne ta jerin nau'ikan maganadiso huɗu huɗu masu mayar da hankali sannan kuma ana tantance su ta hanyar maganadisun dipole don ware ƙazanta a cikin katakon ion.Filin maganadisu na 0.268 T yana jagorantar katako na 7Li3+ zuwa cikin FC.Ana nuna nau'in tsinkayar tsinkayar wannan filin maganadisu a matsayin jajayen lankwasa a cikin Hoto na 4. Ƙwararrun katako na yanzu ya kai 35 mA, wanda ya fi sau 100 sama da na'urar Li3+ na yau da kullum da aka samar a cikin na'urorin lantarki na yau da kullum.Faɗin bugun bugun katako shine 2.0 µs a cikakken faɗin rabin matsakaicin.Gano wani katako na 7Li3+ tare da filin maganadisu na dipole yana nuna nasarar bunching da haɓakar katako.Ƙwararren ion da aka gano ta FC lokacin da ake duba filin maganadisu na dipole an nuna shi a cikin siffa 5. An lura da tsayi mai tsabta guda ɗaya, ya rabu da sauran kololuwa.Tun da duk ions da aka haɓaka zuwa ƙirar ƙira ta linac na RFQ suna da gudu iri ɗaya, igiyoyin ion tare da Q/A iri ɗaya suna da wahala a raba su ta filayen maganadisu dipole.Saboda haka, ba za mu iya bambanta 7Li3+ daga N6+ ko O7+.Koyaya, ana iya ƙididdige adadin ƙazanta daga jihohin cajin da ke makwabtaka da su.Misali, N7+ da N5+ za a iya raba su cikin sauki, yayin da N6+ na iya zama wani bangare na kazanta kuma ana sa ran za su kasance daidai da N7+ da N5+.Adadin gurɓataccen yanayi yana da kusan kashi 2%.
Siffar kayan aikin katako da aka samu ta hanyar bincika filin maganadisu na dipole.Kololuwa a 0.268 T yayi daidai da 7Li3+ da N6+.Nisa mafi girma ya dogara da girman katako akan tsaga.Duk da faffadan kololuwa, 7Li3+ ya rabu da kyau daga 6Li3+, O6+, da N5+, amma da wahala ya rabu da O7+ da N6+.
A wurin FC, an tabbatar da bayanin martaba tare da scintillator plug-in kuma an rubuta shi tare da kyamarar dijital mai sauri kamar yadda aka nuna a cikin Hoto 6. An nuna 7Li3 + pulsed katako tare da halin yanzu na 35 mA don haɓakawa zuwa RFQ mai ƙididdigewa. makamashi na 204 keV / n, wanda ya dace da 1.4 MeV, kuma ana watsa shi zuwa mai gano FC.
An lura da bayanin martabar beam akan allon scintillator na pre-FC (mai launin Fiji, 2.3.0, https://imagej.net/software/fiji/).An kunna filin maganadisu na magnetin dipole na nazari don jagorantar hanzarin katako na Li3+ zuwa ƙirar makamashin RFQ.Dige-dige shuɗi a cikin koren yanki suna haifar da lahani na kayan scintillator.
Mun sami ƙarni na 7Li3+ ions ta hanyar lalatawar laser na saman faren lithium mai ƙarfi, kuma an kama babban katako na ion na yanzu kuma an haɓaka tare da linac na musamman na RFQ da aka ƙera ta amfani da DPIS.A ƙarfin wutar lantarki na 1.4 MeV, mafi girman halin yanzu na 7Li3+ ya kai kan FC bayan nazarin maganadisu shine 35 mA.Wannan yana tabbatar da cewa an aiwatar da mafi mahimmancin ɓangaren aiwatar da tushen neutron tare da juzu'in kinematics ta gwaji.A cikin wannan ɓangaren takarda, za a tattauna gabaɗayan ƙirar ƙaramin tushen neutron, wanda ya haɗa da manyan abubuwan haɓaka makamashi da tashoshi na neutron.Zane ya dogara ne akan sakamakon da aka samu tare da tsarin da ake ciki a cikin dakin gwaje-gwajenmu.Ya kamata a lura cewa za'a iya ƙara ƙarar ƙyalli na katako na ion ta hanyar rage nisa tsakanin foil na lithium da linac RFQ.Shinkafa7 yana misalta gabaɗayan ra'ayi na ƙaƙƙarfan tushen neutron da aka tsara a ma'aunin totur.
Ƙirar ra'ayi na ƙaƙƙarfan tushen neutron da aka tsara a mai haɓakawa (Freecad ya zana, 0.19, https://www.freecadweb.org/).Daga dama zuwa hagu: Laser ion source, solenoid magnet, RFQ linac, matsakaicin wutar lantarki canja wuri (MEBT), IH linac, da kuma hulɗa da dakin don neutron tsara.Ana ba da kariya ta radiation da farko a gaba saboda ƙunƙuntaccen yanayin da aka samar da katako na neutron.
Bayan linac na RFQ, an shirya ƙarin haɓakawa na Inter-dijital H-structure (IH linac) linac 30.IH linacs suna amfani da π-mode drift tube tsarin don samar da manyan gradients filin lantarki a kan wani kewayon gudu.An gudanar da nazarin ra'ayi bisa ga simintin gyare-gyare na tsayin daka na 1D da kwaikwaiyon harsashi na 3D.Lissafi sun nuna cewa 100 MHz IH linac tare da madaidaicin bututu mai ƙarfi (kasa da 450 kV) da ƙaƙƙarfan maganadisu mai ƙarfi na iya haɓaka katako na 40 mA daga 1.4 zuwa 14 MeV a nesa na 1.8 m.Rarraba makamashi a ƙarshen sarkar mai haɓaka ana ƙiyasta a ± 0.4 MeV, wanda ba ya tasiri sosai ga bakan makamashi na neutron da aka samar ta hanyar canjin neutron.Bugu da kari, fitar da katako yana da ƙasa sosai don mayar da hankali kan katakon zuwa ƙaramin katako fiye da yadda ake buƙata don matsakaicin ƙarfi da girman maganadisu quadrupole.A cikin watsa wutar lantarki na matsakaici (MEBT) tsakanin RFQ linac da linac IH, ana amfani da resonator mai haske don kula da tsarin ƙirar.Ana amfani da maganadisu quadrupole guda uku don sarrafa girman katakon gefe.Anyi amfani da wannan dabarar ƙira a cikin masu haɓakawa da yawa31,32,33.Jimlar tsawon tsarin gaba ɗaya daga tushen ion zuwa ɗakin da aka yi niyya an kiyasta bai wuce mita 8 ba, wanda zai iya dacewa da daidaitaccen babban motar tirela.
Za a shigar da manufa ta musanya neutron kai tsaye bayan mai saurin kai tsaye.Muna tattaunawa akan ƙirar tashoshin da aka yi niyya bisa binciken da suka gabata ta amfani da yanayin yanayin kinematic scenarios23.Maƙasudin juyawa da aka bayar da rahoton sun haɗa da ƙaƙƙarfan kayan (polypropylene (C3H6) da titanium hydride (TiH2)) da tsarin manufa mai iskar gas.Kowane burin yana da fa'ida da rashin amfani.Maƙasudai masu ƙarfi suna ba da damar sarrafa kauri daidai.Mafi ƙanƙantar manufa, mafi daidaitaccen tsarin sararin samaniya na samar da neutron.Duk da haka, irin waɗannan hare-hare na iya kasancewa suna da ɗan ƙaramin halayen makaman nukiliya da ba a so da radiation.A gefe guda kuma, makasudin hydrogen zai iya samar da yanayi mai tsabta ta hanyar kawar da samar da 7Be, babban samfurin makamashin nukiliya.Koyaya, hydrogen yana da ƙarancin shinge mai rauni kuma yana buƙatar babban nisa ta jiki don isasshiyar sakin kuzari.Wannan yana da ɗan lahani ga ma'aunin TOF.Bugu da ƙari, idan an yi amfani da fim na bakin ciki don rufe abin da ake nufi da hydrogen, ya zama dole a yi la'akari da asarar makamashi na hasken gamma da fim din na bakin ciki ya haifar da kuma abin da ya faru na lithium.
LICORNE yana amfani da makasudin polypropylene kuma tsarin da aka yi niyya an inganta shi zuwa ƙwayoyin hydrogen da aka rufe da tantalum foil.Yin la'akari da halin yanzu na 100 nA don 7Li34, duka tsarin manufa na iya samar da har zuwa 107 n/s/sr.Idan muka yi amfani da wannan da'awar juzu'in samar da neutron zuwa tushen neutron da aka tsara, to ana iya samun katakon lithium na 7 × 10-8 C ga kowane bugun bugun laser.Wannan yana nufin cewa harba Laser sau biyu kawai a cikin daƙiƙa yana samar da ƙarin 40% na neutron fiye da LICORNE zai iya samarwa a cikin dakika ɗaya tare da ci gaba da katako.Za'a iya ƙara jimlar juzu'i cikin sauƙi ta hanyar haɓaka mitar motsa jiki na Laser.Idan muka ɗauka cewa akwai tsarin Laser na 1 kHz akan kasuwa, matsakaicin matsakaicin ruwan neutron za a iya auna shi cikin sauƙi har zuwa kusan 7 × 109 n/s/sr.
Lokacin da muke amfani da tsarin ƙimar maimaitawa mai girma tare da maƙasudin filastik, wajibi ne don sarrafa ƙirar zafi akan maƙasudan saboda, alal misali, polypropylene yana da ƙarancin narkewa na 145-175 ° C da ƙarancin ƙarancin thermal na 0.1-0.22 W / m/K.Don 14 MeV lithium-ion katako, 7 µm kauri polypropylene manufa ya isa ya rage ƙarfin katako zuwa matakin amsawa (13.098 MeV).Yin la'akari da jimillar tasirin ions da aka yi ta harbin Laser guda ɗaya a kan manufa, an kiyasta sakin makamashi na ions lithium ta hanyar polypropylene a 64mJ/pulse.Tsammanin cewa duk makamashin yana canjawa wuri a cikin da'irar da diamita na 10 mm, kowane bugun jini yayi daidai da hawan zafin jiki na kimanin 18 K / bugun jini.Sakin makamashi akan makasudin polypropylene ya dogara ne akan zato mai sauƙi cewa duk asarar makamashi ana adana su azaman zafi, ba tare da radiation ko wasu asarar zafi ba.Tunda ƙara yawan bugun jini a cikin daƙiƙa yana buƙatar kawar da haɓakar zafi, zamu iya amfani da maƙasudin tsiri don guje wa sakin kuzari a daidai wannan batu23.Tsammanin tabo na katako na mm 10 akan maƙasudi tare da ƙimar maimaita laser na 100 Hz, saurin duban tef ɗin polypropylene zai zama 1 m/s.Matsakaicin ƙimar maimaitawa yana yiwuwa idan an ba da izinin zoba tabo.
Mun kuma bincika hari tare da batir hydrogen, saboda ana iya amfani da katako mai ƙarfi ba tare da lalata manufa ba.Za a iya daidaita katakon neutron cikin sauƙi ta hanyar canza tsayin ɗakin gas da matsa lamba na hydrogen a ciki.Ana amfani da ɓangarorin ƙarfe na bakin ciki sau da yawa a cikin injina don raba yankin gas ɗin da aka yi niyya daga vacuum.Sabili da haka, ya zama dole don ƙara ƙarfin wutar lantarki na lithium-ion da ya faru don rama asarar makamashi akan foil.Taron da aka yi niyya da aka bayyana a cikin rahoton 35 ya ƙunshi kwandon aluminium mai tsayi 3.5 cm mai tsayi tare da matsin iskar H2 na 1.5 atm.Matsakaicin 16.75 MeV lithium ion katako yana shiga baturin ta cikin iska mai sanyaya 2.7 µm Ta foil, kuma makamashin lithium ion beam a ƙarshen baturin yana raguwa zuwa matakin amsawa.Don ƙara ƙarfin katako na batir lithium-ion daga 14.0 MeV zuwa 16.75 MeV, IH linac dole ne a tsawanta da kusan 30 cm.
An kuma yi nazari kan fitar da neutrons daga maƙasudan ƙwayoyin iskar gas.Ga maƙasudin iskar gas na LICORNE da aka ambata, GEANT436 simulations sun nuna cewa ana samar da neutrons masu ma'ana sosai a cikin mazugi, kamar yadda aka nuna a Hoto 1 a [37].Magana 35 yana nuna kewayon makamashi daga 0.7 zuwa 3.0 MeV tare da matsakaicin mazugi na buɗewa na 19.5 ° dangane da jagorancin yaduwa na babban katako.Neutrons masu tsayin daka na iya rage yawan adadin kayan kariya a mafi yawan kusurwoyi, rage nauyin tsarin da kuma samar da sassauci mafi girma a cikin shigar da kayan aikin aunawa.Daga ra'ayi na kariyar radiation, ban da neutrons, wannan makasudin iskar gas yana fitar da hasken gamma 478 keV isotropically a cikin tsarin haɗin gwiwar centroid38.Ana samar da waɗannan γ-ray ne sakamakon lalatar 7Be da 7Li deexcitation, wanda ke faruwa lokacin da firamaren Li beam ya buga taga shigarwar Ta.Koyaya, ta ƙara mai kauri 35 Pb/C cylindrical collimator, za a iya rage bango sosai.
A matsayin madaidaicin manufa, mutum na iya amfani da taga plasma [39, 40], wanda ke ba da damar cimma matsakaicin matsa lamba na hydrogen da ƙaramin yanki na tsarar neutron, kodayake yana ƙasa da ingantattun maƙasudai.
Muna bincika zaɓuɓɓukan niyya na canjin neutron don rarraba makamashi da ake tsammanin da girman katako na katako na lithium ion ta amfani da GEANT4.Simulators ɗinmu suna nuna daidaitaccen rarraba makamashin neutron da rarraba angular don maƙasudin hydrogen a cikin adabin da ke sama.A cikin kowane tsarin da aka yi niyya, za a iya samar da neutrons masu ma'ana sosai ta hanyar juzu'i mai jujjuyawar kinematic mai ƙarfi wanda katako mai ƙarfi na 7Li3+ ke motsawa akan manufa mai wadatar hydrogen.Don haka, ana iya aiwatar da sabbin hanyoyin neutron ta hanyar haɗa fasahar da ta riga ta kasance.
Yanayin iska mai haske na Laser ya sake haifar da gwaje-gwajen ƙirar ion katako kafin ƙaddamar da zanga-zangar.Laser shine tebur nanosecond Nd: YAG tsarin tare da ƙarfin laser na 1012 W/cm2, babban tsayin raƙuman ruwa na 1064 nm, ƙarfin tabo na 800 mJ, da lokacin bugun jini na 6 ns.An kiyasta diamita na tabo akan manufa a 100 µm.Saboda ƙarfe na lithium (Alfa Aesar, 99.9% mai tsabta) yana da taushi sosai, ainihin abin da aka yanke yana danna cikin mold.Girman bango 25 mm × 25 mm, kauri 0.6 mm.Lalacewa mai kama da dutse yana faruwa a saman wanda ake niyya lokacin da Laser ya buge shi, don haka wani dandamali mai motsi yana motsa makasudin don samar da wani sabon yanki na saman wanda ake niyya tare da kowane harbin Laser.Don kauce wa sake haɗuwa saboda ragowar gas, an ajiye matsa lamba a cikin ɗakin a ƙasa da kewayon 10-4 Pa.
Ƙarfin farko na plasma Laser ƙarami ne, tun da girman wurin Laser yana da 100 μm kuma a cikin 6 ns bayan tsararsa.Za'a iya ɗaukar ƙarar a matsayin ainihin batu kuma a faɗaɗa shi.Idan an sanya mai ganowa a nesa xm daga wurin da aka nufa, to, siginar da aka karɓa ta yi biyayya ga dangantaka: ion current I, ion isowa lokacin t, da pulse wide τ.
An yi nazarin plasma da aka samar ta hanyar TOF tare da FC da kuma mai nazarin makamashi (EIA) wanda yake a nesa na 2.4 m da 3.85 m daga maƙasudin laser.FC tana da grid na suppressor mai karkata zuwa -5kV don hana electrons.EIA tana da digo na 90 electrostatic deflector wanda ya ƙunshi na'urorin lantarki guda biyu na coaxial karfe cylindrical tare da irin ƙarfin lantarki iri ɗaya amma sabanin polarity, tabbatacce a waje da korau a ciki.Plasma mai faɗaɗa ana nusar da shi a cikin maɓalli a bayan ramin kuma an karkatar da shi ta hanyar wutar lantarki da ke wucewa ta silinda.Ions masu gamsar da alaƙa E/z = eKU ana gano su ta amfani da na'urar lantarki ta biyu (SEM) (Hamamatsu R2362), inda E, z, e, K, da U sune makamashin ion, yanayin caji, da caji sune abubuwan geometric EIA. .electrons, bi da bi, da yuwuwar bambanci tsakanin na'urorin lantarki.Ta hanyar canza ƙarfin lantarki a kan mai kashewa, mutum zai iya samun kuzari da rarraba cajin ions a cikin plasma.Ƙarfin wutar lantarki U/2 EIA yana cikin kewayon daga 0.2 V zuwa 800 V, wanda yayi daidai da makamashin ion a cikin kewayon daga 4 eV zuwa 16 keV kowace jiha.
Rarraba yanayin cajin ions da aka bincika a ƙarƙashin yanayin hasken wuta na Laser da aka bayyana a cikin sashe "Tsarin ɓangarorin lithium cikakke" an nuna su a cikin Fig.8.
Binciken rarraba yanayin yanayin cajin ions.Anan ga bayanin martabar lokacin yawan ion na yanzu da aka yi nazari tare da EIA kuma an ƙididdige shi a 1 m daga foil na lithium ta amfani da ma'auni.(1) da (2).Yi amfani da yanayin hasken wuta na Laser da aka kwatanta a cikin sashin "Ƙirƙirar Ƙwararren Ƙwararren Lithium Beam".Ta hanyar haɗa kowane nau'i na yanzu, an ƙididdige adadin ions a cikin plasma, wanda aka nuna a hoto 3.
Maɓuɓɓugan ion Laser na iya isar da ƙaƙƙarfan katako mai ion mA da yawa tare da babban caji.Koyaya, isar da katako yana da matukar wahala saboda ƙin cajin sararin samaniya, don haka ba a yi amfani da shi sosai ba.A cikin tsarin al'ada, ana fitar da katako na ion daga plasma kuma ana jigilar su zuwa na'urar gaggawa ta farko tare da layin katako tare da maɗauran maida hankali da yawa don siffanta katakon ion bisa ga iyawar na'urar.A cikin firam ɗin cajin sararin samaniya, ƙullun suna bambanta ba tare da layi ba, kuma ana samun hasara mai tsanani, musamman ma a yankin ƙananan hanzari.Don shawo kan wannan matsala a cikin haɓaka na'urorin haɓaka carbon na likita, an gabatar da sabon tsarin isar da katako na DPIS41.Mun yi amfani da wannan dabarar don haɓaka katako mai ƙarfi na lithium-ion daga sabon tushen neutron.
Kamar yadda aka nuna a cikin fig.4, sararin da ake samar da plasma a cikinsa da kuma fadada shi yana kewaye da kwandon karfe.Wurin da ke kewaye ya shimfiɗa zuwa ƙofar RFQ resonator, gami da ƙarar da ke cikin nada solenoid.An yi amfani da ƙarfin lantarki na 52 kV a cikin akwati.A cikin resonator na RFQ, ions ana jan su ta yuwuwar ta rami diamita na mm 6 ta ƙasan RFQ.An kawar da dakarun da ba na layi ba a kan layin katako yayin da ake jigilar ions a cikin jihar plasma.Bugu da ƙari, kamar yadda aka ambata a sama, mun yi amfani da filin solenoid a hade tare da DPIS don sarrafawa da kuma ƙara yawan ions a cikin cirewa.
Mai saurin RFQ ya ƙunshi ɗaki mai siliki kamar yadda aka nuna a fig.9 a ba.A ciki, an sanya sanduna huɗu na tagulla maras isashshen oxygen zuwa quadrupole-symmetrically a kusa da axis (Fig. 9b).4 sanduna da ɗakuna suna samar da da'irar RF mai resonant.Filin RF da aka jawo yana haifar da wutar lantarki mai canza lokaci a fadin sandar.Ions da aka dasa a tsayi a kusa da axis ana gudanar da su a gefe ta filin quadrupole.A lokaci guda, an daidaita tip na sanda don ƙirƙirar filin lantarki axial.Filin axial yana raba katako mai ci gaba da allura zuwa jerin bugun bugun katako da ake kira katako.Kowane katako yana ƙunshe a cikin takamaiman lokacin zagayowar RF (10 ns).Bimukan da ke kusa suna nisa bisa ga lokacin mitar rediyo.A cikin linac na RFQ, 2 µs katako daga tushen ion Laser an canza shi zuwa jerin katako 200.Sa'an nan kuma ƙara da katako zuwa ƙarfin ƙididdigewa.
Mai saurin sauri RFQ.(a) (hagu) Duban waje na ɗakin linac na RFQ.(b) (dama) Wutar lantarki mai sanda huɗu a cikin ɗakin.
Babban sigogin ƙira na linac na RFQ sune wutar lantarki na sanda, mitar resonant, radius rami, da daidaitawar lantarki.Zaɓi ƙarfin lantarki akan sanda ± 29 kV domin filin lantarkinsa ya kasance ƙasa da madaidaicin rushewar wutar lantarki.Ƙarƙashin mitar resonant, mafi girman ƙarfin mayar da hankali na gefe da ƙarami matsakaicin filin hanzari.Manyan radiyo masu buɗewa suna ba da damar ƙara girman katako kuma, saboda haka, ƙara ƙarfin katako saboda ƙaramar cajin sararin samaniya.A gefe guda, radiyoyin buɗewa mafi girma suna buƙatar ƙarin ikon RF don kunna linac na RFQ.Bugu da ƙari, an iyakance shi ta hanyar ingancin buƙatun shafin.Dangane da waɗannan ma'auni, an zaɓi mitar resonant (100 MHz) da radiyon buɗe ido (4.5 mm) don haɓakar katako mai tsayi na yanzu.An zaɓi tsarin daidaitawa don rage asarar katako da haɓaka haɓakar haɓakawa.An inganta ƙirar sau da yawa don samar da ƙirar linac na RFQ wanda zai iya hanzarta ions 7Li3 + a 40 mA daga 22 keV / n zuwa 204 keV / n a cikin 2 m.Ƙarfin RF da aka auna yayin gwajin shine 77 kW.
RFQ linacs na iya haɓaka ions tare da takamaiman kewayon Q/A.Sabili da haka, lokacin nazarin katako da aka ciyar da shi zuwa ƙarshen mai saurin kai tsaye, ya zama dole a la'akari da isotopes da sauran abubuwa.Bugu da ƙari, ions da ake so, wani ɓangare na hanzari, amma sun sauko a ƙarƙashin yanayin haɓakawa a tsakiyar na'urar, har yanzu suna iya saduwa da tsare-tsare na gefe kuma ana iya jigilar su zuwa ƙarshe.Hasken da ba'a so ban da injiniyoyi 7Li3+ ana kiransa ƙazanta.A cikin gwaje-gwajenmu, 14N6+ da 16O7+ ƙazanta sun kasance mafi damuwa, tun lokacin da foil ɗin ƙarfe na lithium yana amsawa tare da oxygen da nitrogen a cikin iska.Waɗannan ions suna da rabon Q/A wanda za'a iya haɓakawa tare da 7Li3+.Muna amfani da maganadisu dipole don raba katako na inganci daban-daban da inganci don nazarin katako bayan linac na RFQ.
Layin katako bayan linac na RFQ an ƙera shi don isar da ingantaccen katako na 7Li3+ zuwa FC bayan magnet dipole.-400 V ana amfani da na'urorin nuna son kai don murkushe electrons na biyu a cikin kofin don auna daidai ƙarfin halin yanzu.Tare da wannan na'urorin gani, an raba hanyoyin ion zuwa dipoles kuma an mayar da hankali a wurare daban-daban dangane da Q/A.Saboda dalilai daban-daban kamar saurin yaɗawa da ƙin cajin sararin samaniya, katakon da aka mai da hankali yana da takamaiman faɗin.Za a iya raba nau'in ne kawai idan nisa tsakanin wurare masu mahimmanci na nau'in ion guda biyu ya fi girman katako.Don samun mafi girman ƙuduri mai yuwuwa, ana shigar da tsaga a kwance kusa da kugu, inda katakon ke kusan tattarawa.An shigar da allon scintillation (CsI (Tl) daga Saint-Gobain, 40 mm × 40 mm × 3 mm) tsakanin tsaga da PC.An yi amfani da scintillator don tantance mafi ƙarancin tsaga wanda ɓangarorin da aka ƙera su wuce don ingantaccen ƙuduri kuma don nuna girman katako mai karɓuwa don manyan katakon ion masu nauyi na yanzu.Hoton katako a kan scintillator ana yin rikodin ta kyamarar CCD ta taga mara amfani.Daidaita taga lokacin bayyanarwa don rufe duk faɗin bugun bugun katako.
Abubuwan da aka yi amfani da su ko aka yi nazari a cikin binciken na yanzu suna samuwa daga mawallafa bisa ga buƙatu mai ma'ana.
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Anderson, IS et al.Yiwuwar nazarin ƙananan hanyoyin neutron a accelerators.ilimin lissafi.Wakili 654, 1-58.doi.org/10.1016/j.physrep.2016.07.007 (2016).
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