An daɗe da kafa ƙa'idar da aka saba da ita ta "ƙari tana da ƙarfi" a yawancin sassa na al'umma, gami da kimiyya da fasaha. Duk da haka, a cikin al'amuran yau da kullum, aiwatar da aikace-aikacen da ake amfani da shi na cewa "kananan, amma mai girma" yana ƙara karuwa. Wannan yana bayyana duka a cikin kwamfutoci, wanda a baya ya ɗauki ɗaki duka, amma yanzu ya dace a cikin dabino na yaro, kuma a cikin masu haɓaka ƙwayoyin cuta. Ee, tuna Babban Hadron Collider (LHC), wanda girmansa mai ban sha'awa (26 m a tsayi) an nuna a zahiri a cikin sunansa? Don haka, wannan ya riga ya zama tarihi a cewar masana kimiyya daga DESY, waɗanda suka ɓullo da ƙaramin juzu'in na'urar haɓakawa, wanda ba shi da ƙasa a cikin aiwatar da cikakken girman wanda ya gabace shi. Bugu da ƙari, ƙaramin ƙararrakin har ma ya kafa sabon rikodin duniya a tsakanin terahertz accelerators, ninka ƙarfin kuzarin na'urorin lantarki. Ta yaya aka ɓullo da ƙaramin ƙararrawa, menene ainihin ƙa'idodin aikinsa, kuma menene gwaje-gwaje masu amfani suka nuna? Rahoton ƙungiyar bincike zai taimaka mana gano wannan. Tafi
Tushen bincike
A cewar Dongfang Zhang da abokan aikinsa na DESY (Jamus Electron Synchrotron), wadanda suka ƙera mini-accelerator, ultrafast hanyoyin lantarki suna taka muhimmiyar rawa a rayuwar al'umma ta zamani. Yawancin su suna bayyana a cikin magani, haɓaka kayan lantarki da binciken kimiyya. Babbar matsala tare da masu haɓaka layin layi na yanzu suna amfani da oscillators na mitar rediyo shine tsadar su, hadaddun kayan aikin, da amfani mai ban sha'awa. Kuma irin wannan gazawar tana iyakance wadatar irin waɗannan fasahohin zuwa faɗuwar masu amfani.
Waɗannan matsalolin da ke bayyane babban abin ƙarfafawa ne don haɓaka na'urori waɗanda girmansu da ƙarfinsu ba zai haifar da tsoro ba.
Daga cikin sabbin sabbin abubuwa a cikin wannan masana'antar akwai masu haɓaka terahertz, waɗanda ke da “fa'idodi da yawa”:
- Ana sa ran gajerun raƙuman ruwa da gajeriyar bugun jini na terahertz radiation za su ƙara girman kofa rushewa*, lalacewa ta hanyar filin, wanda zai kara yawan hanzarin hanzari;
Rushewar Lantarki* - haɓaka mai kaifi a ƙarfin halin yanzu lokacin da aka yi amfani da ƙarfin lantarki sama da mahimmanci.
- kasancewar ingantattun hanyoyi don samar da babban filin terahertz radiation yana ba da damar aiki tare na ciki tsakanin electrons da filayen motsa jiki;
- Ana iya amfani da hanyoyin gargajiya don ƙirƙirar irin waɗannan na'urori, amma farashin su, lokacin samarwa da girman su zai ragu sosai.
Masana kimiyya sun yi imanin cewa na'urar hawan terahertz ta millimita yarjejeniya ce tsakanin na'urori na yau da kullun da ake da su a halin yanzu da kuma na'urori masu ƙararrawa waɗanda ake haɓaka, amma suna da illoli da yawa saboda ƙananan girman su.
Masu bincike ba su musanta cewa fasahar haɓaka fasahar terahertz ta kasance cikin haɓaka na ɗan lokaci ba. Sai dai a nasu ra'ayin, har yanzu akwai abubuwa da dama a wannan fanni da ba a yi nazari ba, ba a gwada su ba, ba a aiwatar da su ba.
A cikin aikin su, wanda muke la'akari a yau, masana kimiyya sun nuna iyawar STEAM (segmented terahertz electron totur da manipulator) - segmented terahertz electron totur da manipulator. STEAM yana ba da damar rage tsayin katakon lantarki zuwa tsawon lokaci na ɗan lokaci, ta haka yana ba da ikon sarrafa na biyu na femtosecond akan lokacin haɓakawa.
Zai yiwu a cimma filin haɓakawa na 200 MV / m (MV - megavolt), wanda ke haifar da rikodin rikodi na terahertz na> 70 keV (kiloelectronvolt) daga katako na lantarki da aka saka tare da makamashi na 55 keV. Ta wannan hanyar, an sami ƙarfin ƙarfin lantarki har zuwa 125 keV.
Tsarin na'ura da aiwatarwa
Hoto No. 1: zane na na'urar da ake nazari.
Hoto No. 1-2: a - zane na ɓullo da 5-Layer segmented tsarin, b - Rabo na ƙididdiga hanzari da kuma shugabanci na electron yaduwa.
Ana samar da katako na lantarki (55 keV) daga gun electron* kuma an gabatar da su a cikin terahertz STEAM-buncher (kwamfutar katako), bayan haka sun wuce cikin STEAM-linac (linzamin kwamfuta accelerator*).
Gun lantarki* - na'urar don samar da katako na electrons na tsarin da ake bukata da makamashi.
Mai saurin sauri na layi* - na'ura mai sauri wanda ɓangarorin da aka caje su ke wucewa ta tsarin sau ɗaya kawai, wanda ke bambanta mai saurin linzamin kwamfuta daga mai hawan keke (misali, LHC).
Dukansu na'urorin STEAM suna karɓar bugun terahertz daga Laser kusa da infrared (NIR), wanda kuma yana ƙone photocathode na bindigar lantarki, yana haifar da aiki tare na ciki tsakanin electrons da filayen haɓakawa. Ana haifar da bugun jini na ultraviolet don ɗaukar hoto a photocathode ta matakai biyu masu jere GVG* ainihin tsawon haske na kusa-infrared haske. Wannan tsari yana jujjuya bugun laser na 1020nm farko zuwa 510 nm sannan zuwa 255 nm.
GVG* (Optical Second Harmonic Generation) shine tsarin hada photons na mitar guda daya a yayin mu'amala da wani abu mara amfani, wanda ke kaiwa ga samuwar sabbin photon tare da ninki biyu makamashi da mita, da kuma rabin tsawon zangon.
Ragowar katakon Laser na NIR ya kasu kashi 4, wadanda ake amfani da su don samar da bugun terahertz guda hudu ta hanyar samar da bambance-bambancen mitar intra-pulse.
Sannan ana isar da bugun terahertz guda biyu ga kowace na'urar STEAM ta hanyar sifofin ƙaho mai ma'ana waɗanda ke jagorantar makamashin terahertz zuwa yankin hulɗar ta hanyar yaduwar lantarki.
Lokacin da electrons suka shiga kowace na'urar STEAM, ana fallasa su ga abubuwan lantarki da na maganadisu Sojojin Lorentz*.
Lorentz karfi* - ƙarfin da filin lantarki ke aiki akan ɓangarorin da aka caji.
A wannan yanayin, filin lantarki yana da alhakin haɓakawa da raguwa, kuma filin maganadisu yana haifar da juzu'i na gefe.
Hoto #2
Kamar yadda muke gani a cikin hotuna 2 и 2b, A cikin kowace na'urar STEAM, terahertz beams an raba su ta hanyar ɓangarorin ƙarfe na bakin ciki zuwa yadudduka daban-daban na kauri daban-daban, kowannensu yana aiki azaman jagorar igiyar ruwa, yana canja wani ɓangare na jimlar makamashi zuwa yankin hulɗar. Hakanan akwai faranti na dielectric a cikin kowane Layer don daidaita lokacin isowar terahertz gaban igiyar ruwa* tare da gaban electrons.
Wavefront* - fuskar da igiyar ruwa ta kai ga.
Duk na'urorin STEAM guda biyu suna aiki ne a yanayin lantarki, wato, ta hanyar da za a shigar da filin lantarki da kuma danne filin maganadisu a tsakiyar yankin hulɗar.
A cikin na'urar farko, electrons suna lokacin wucewa tsallake sifiri* filin terahertz, inda ake ƙara yawan adadin lokacin filin lantarki kuma aka rage matsakaicin filin.
Ketare sifili* - wurin da babu tashin hankali.
Wannan saitin yana haifar da wutsiyar igiyar wutar lantarki don sauri kuma kansa ya ragu, yana haifar da mai da hankali a tsayin ballistic (2 и 2s).
A cikin na'ura ta biyu, an saita aiki tare na lantarki da terahertz radiation ta yadda wutar lantarki ta fuskanci mummunan zagayowar filin lantarki na terahertz. Wannan saitin yana haifar da ci gaba da ci gaba da sauri (2b и 2d).
Laser na NIR shine tsarin Yb:YLF mai sanyaya cryogenically wanda ke samar da bugun gani na tsawon 1.2 ps da kuzarin 50 mJ a tsawon 1020 nm da adadin maimaitawa na 10 Hz. Kuma terahertz bugun jini tare da mitar tsakiya na 0.29 terahertz (lokacin 3.44 ps) ana haifar da su ta hanyar gaban bugun bugun zuciya.
Don iko da STEAM-buncher (kwamfutar katako) kawai 2 x 50 nJ na makamashin terahertz da aka yi amfani da shi, kuma STEAM-linac (mai saurin sauri) yana buƙatar 2 x 15 mJ.
Diamita na ramukan mashiga da fitarwa na na'urorin STEAM guda biyu shine microns 120.
An ƙera maƙalar katako tare da yadudduka uku na daidai tsayi (0 mm), waɗanda aka sanye da faranti na siliki (ϵr = 225) na tsawon 4.41 da 0.42 mm don sarrafa lokaci. Matsakaicin tsayi daidai na yadudduka na kwampreso suna nuna gaskiyar cewa babu haɓakawa (2s).
Amma a cikin madaidaiciyar totur, tsayinsa sun riga sun bambanta - 0.225, 0.225 da 0.250 mm (+ fused quartz faranti 0.42 da 0.84 mm). Haɓakawa a tsayin Layer yana bayyana haɓakar saurin electrons yayin haɓakawa.
Masana kimiyya sun lura cewa adadin yadudduka ne kai tsaye alhakin ayyukan kowane ɗayan na'urori biyu. Samun mafi girman ƙimar haɓakawa, alal misali, zai buƙaci ƙarin yadudduka da daidaita tsayi daban-daban don haɓaka hulɗa.
Sakamakon gwaje-gwaje masu amfani
Na farko, masu binciken suna tunatar da cewa a cikin na'urori masu sauri na mitar rediyo na gargajiya, tasirin tasirin wutar lantarki na ɗan lokaci akan kaddarorin haɓakar katako yana faruwa ne saboda canjin yanayin wutar lantarki da aka samu yayin mu'amalar electrons daban-daban a cikin igiyar da ke isowa. a lokuta daban-daban. Don haka, ana iya tsammanin filayen da ke da manyan gradients da katako mai tsayi mai tsayi zai haifar da yaduwar makamashi mai girma. Itatuwan allura na dogon lokaci kuma na iya haifar da ƙima mafi girma fitarwa*.
Fitowa* - sararin lokaci wanda aka matse shi da ingantacciyar katako na barbashi da aka caje.
A cikin yanayin haɓakar terahertz, lokacin filin tashin hankali ya fi guntu sau 200. Don haka, tashin hankali* filin da aka goyan baya zai zama mafi girma sau 10.
Ƙarfin filin lantarki* - mai nuna alamar wutar lantarki, daidai da rabon ƙarfin da aka yi amfani da shi zuwa cajin batu na tsaye wanda aka sanya a wani wuri da aka ba a cikin filin zuwa girman wannan cajin.
Don haka, a cikin injin ƙarar terahertz, filayen gradients ɗin da aka samu ta hanyar lantarki na iya zama umarni da yawa na girma sama da na na'ura ta al'ada. Ma'auni na lokacin da ake ganin lanƙwan filin zai zama ƙarami sosai. Ya biyo bayan haka cewa tsawon lokacin da aka gabatar da wutar lantarki zai yi tasiri sosai.
Masana kimiyya sun yanke shawarar gwada waɗannan ka'idodin a aikace. Don yin wannan, sun gabatar da igiyoyin lantarki na tsawon lokaci daban-daban, waɗanda aka sarrafa ta hanyar matsawa ta hanyar amfani da na'urar STEAM ta farko (STEAM-buncher).
Hoto #3
A cikin yanayin da ba a haɗa compressor zuwa tushen wutar lantarki ba, igiyoyin electrons (55 keV) tare da cajin ~ 1 fC (femtocoulomb) sun wuce kusan 300 mm daga bindigar lantarki zuwa na'ura mai saurin sauri (STEAM-linac). Waɗannan na'urorin lantarki na iya faɗaɗa ƙarƙashin tasirin ƙarfin cajin sararin samaniya har zuwa tsawon fiye da 1000 fs (femtoseconds).
A wannan lokacin, wutar lantarki ta mamaye kusan kashi 60% na rabin tsawon zangon filin haɓakawa a mitar 1,7 ps, wanda ya haifar da bakan ƙarfin haɓakawa bayan haɓakawa tare da kololuwa a 115 keV da rabin nisa na rarraba makamashi. fiye da 60 keV (3).
Don kwatanta waɗannan sakamakon da waɗanda ake sa ran, yanayin yaɗuwar wutar lantarki ta hanyar na'ura mai sauri na madaidaiciya an daidaita shi lokacin da electrons ba su daidaita tare da (watau ba tare da daidaitawa tare da) mafi kyawun lokacin allura ba. Lissafi na wannan yanayin ya nuna cewa karuwar makamashin lantarki ya dogara sosai akan lokacin allura, zuwa ma'auni na subpicose na lokaci (3b). Wato, tare da mafi kyawun saiti, wutar lantarki za ta fuskanci cikakken rabin zagaye na hanzarin radiation na terahertz a kowane Layer (3s).
Idan electrons sun zo a lokuta daban-daban, suna samun raguwa a cikin hanzari a farkon Layer, wanda ke sa su dauki tsawon lokaci don tafiya ta cikinsa. Desynchronization sannan yana ƙaruwa a cikin yadudduka masu zuwa, yana haifar da jinkirin da ba a so (3d).
Domin rage mummunan tasiri na tsawo na ɗan lokaci na katako na lantarki, na'urar STEAM ta farko tana aiki a yanayin matsawa. Tsawon lokacin katako na lantarki a linac an inganta shi zuwa mafi ƙarancin ~ 350 fs (rabin nisa) ta hanyar daidaita ƙarfin terahertz da aka kawo zuwa kwampreso da canza linac zuwa yanayin ƙyanƙyashe (4b).
Hoto #4
An saita mafi ƙarancin lokacin katako daidai da tsawon lokacin bugun bugun photocathode UV, wanda shine ~ 600 fs. Nisa tsakanin kwampreso da tsiri shima ya taka muhimmiyar rawa, wanda ya iyakance saurin kauri. Tare, waɗannan matakan suna ba da damar daidaitaccen femtosecond a lokacin allura na lokacin haɓakawa.
Akan hoton 4 ana iya ganin cewa yaduwar makamashin katakon lantarki da aka matsa bayan ingantaccen haɓakawa a cikin na'ura mai sauri yana raguwa da ~ 4 sau idan aka kwatanta da wanda ba a matsawa ba. Sakamakon haɓakawa, bakan makamashi na katakon da aka matsa yana jujjuya shi zuwa manyan kuzari, sabanin katakon da ba a matsawa ba. Kololuwar bakan makamashi bayan haɓakawa shine kusan 115 keV, kuma wutsiya mai ƙarfi ta kai kusan 125 keV.
Waɗannan alkalumman, bisa ga madaidaicin sanarwa na masana kimiyya, sabon rikodin hanzari ne (kafin haɓakawa yana da 70 keV) a cikin kewayon terahertz.
Amma domin rage tarwatsewar makamashi (4), dole ne a samu ma fi guntu katako.
Hoto #5
A cikin yanayin ƙaddamar da katako wanda ba a haɗa shi ba, dogaro na parabolic na girman katako a kan halin yanzu yana nuna ƙaddamarwa mai jujjuyawa a cikin kwatancen kwance da a tsaye: εx, n = 1.703 mm * mrad da εy, n = 1.491 mm * mrad (5).
Matsawa, bi da bi, ya inganta juzu'i ta hanyar sau 6 zuwa εx,n = 0,285 mm*mrad (a kwance) da εy,n = 0,246 mm*mrad (a tsaye).
Yana da kyau a lura cewa matakin raguwar fitarwa yana kusan ninki biyu kamar girman ƙimar rage tsawon lokacin katako, wanda shine ma'auni na rashin daidaituwa na yanayin hulɗa tare da lokacin lokacin da electrons ke samun mai da hankali mai ƙarfi da karkatar da filin maganadisu yayin haɓakawa (5b и 5s).
Akan hoton 5b Ana iya ganin cewa electrons da aka gabatar a mafi kyawun lokaci suna fuskantar tsawon rabin zagaye na hanzarin filin lantarki. Amma electrons da suka zo kafin ko bayan mafi kyawun lokaci suna samun ƙarancin hanzari har ma da ɓarnawar ɓangarori. Irin waɗannan electrons suna ƙarewa da ƙarancin kuzari, a cikin magana.
Ana lura da irin wannan yanayin lokacin da aka fallasa shi zuwa filin maganadisu. Electrons da aka yi musu allura a mafi kyawun lokaci suna samun daidaitattun adadin filayen maganadisu mai kyau da mara kyau. Idan gabatarwar electrons ya faru kafin mafi kyawun lokaci, to, akwai ƙarin fa'idodi masu kyau da ƙananan ƙananan. Idan an gabatar da electrons daga baya fiye da mafi kyawun lokaci, za a sami ƙarancin tabbatacce kuma mafi ƙarancin (5s). Kuma irin wannan karkacewar yana haifar da gaskiyar cewa electron na iya karkata zuwa hagu, dama, sama ko ƙasa, dangane da matsayinsa dangane da axis, wanda ke haifar da karuwa a cikin juzu'i mai jujjuyawa daidai da mayar da hankali ko rage girman katako.
Don ƙarin cikakken sani tare da nuances na binciken, Ina ba da shawarar dubawa и masa.
Epilogue
A taƙaice, aikin gaggawa zai ƙaru idan an rage tsawon lokacin igiyar lantarki. A cikin wannan aikin, tsawon lokacin katakon da za'a iya cimma ya iyakance ta hanyar joometry na shigarwa. Amma, a ka'idar, tsawon lokacin katako na iya kaiwa ƙasa da 100 fs.
Masana kimiyya kuma sun lura cewa za a iya inganta ingancin katako ta hanyar rage tsayin yadudduka da kuma kara yawan su. Duk da haka, wannan hanya ba tare da matsaloli ba, musamman yana ƙara rikitarwa na kera na'urar.
Wannan aikin shine matakin farko na ƙarin fa'ida da cikakken bincike na ƙaramin siga na mai saurin layi. Duk da cewa samfurin da aka gwada ya riga ya nuna kyakkyawan sakamako, wanda za'a iya kiransa rikodin rikodin, har yanzu akwai sauran aiki da yawa.
Na gode da hankalin ku, ku kasance da sha'awar kuma ku sami mako mai kyau kowa da kowa! 🙂
Na gode da kasancewa tare da mu. Kuna son labaran mu? Kuna son ganin ƙarin abun ciki mai ban sha'awa? Goyon bayan mu ta hanyar ba da oda ko ba da shawara ga abokai, Rangwamen 30% ga masu amfani da Habr akan keɓaɓɓen analogue na sabar matakin shigarwa, wanda mu muka ƙirƙira muku: (akwai tare da RAID1 da RAID10, har zuwa 24 cores kuma har zuwa 40GB DDR4).
Dell R730xd sau 2 mai rahusa? Nan kawai a cikin Netherlands! Dell R420 - 2x E5-2430 2.2Ghz 6C 128GB DDR3 2x960GB SSD 1Gbps 100TB - daga $99! Karanta game da
source: www.habr.com