Njengoba amashubhu-X-ray ukusebenza?

X-ray kukhona elakhiwe ngokuguqula lukagesi electron kuma izinhlayiyana eziningi zokukhanya, okuyinto eyenzeka ngo-tube-X-ray. Ubuningi (ukuchayeka) nekhwalithi (spectrum) emisebeni kungase kushintshwe ngokushintsha zamanje, voltage isikhathi insimbi.

Umgomo we operation

-X-ray amashubhu (isithombe enikezwa esihlokweni) kukhona amandla converters. Zithola ke kunethiwekhi futhi iguqulwe ibe nezinye izinhlobo - eyenza umuntu acabange eseZwini ngemisebe ukushisa, lona wamuva kuyinto eceleni engathandeki. -X-ray tube kudivayisi kangangokuthi maximizes ukukhiqizwa izinhlayiyana eziningi zokukhanya futhi dissipates ukushisa ngokushesha ngangokunokwenzeka.

I tube yidivayisi elula, ngokuvamile ehlanganisa izici ezimbili eziyisisekelo - a cathode kanye anode. Lapho zamanje ogeleza usuka cathode kuya anode, ama-electron, ulahlekelwe amandla, okuholela isizukulwane kwama-X ray.

anode

I anode wumkhakha, lapho ekushayweni ephezulu amandla izinhlayiyana eziningi zokukhanya kukhiqizwa. Lena isici kuqhathaniswa omkhulu wensimbi okuyinto ixhunywe isigxobo omuhle wesifunda kagesi. It has imisebenzi emibili esemqoka:

• Ishintsha amandla electron-X-ray emisebeni ku,
• It dissipates ukushisa.

Indaba for the anode kuyakhethwa ukuthuthukisa le misebenzi.

Kahle kahle, iningi electron kufanele akha izinhlayiyana eziningi zokukhanya ephezulu amandla, kunokuba ukushisa. Inani labantu okufanele lifinyelelwe amandla inani, okuyinto ibe X-emisebeni (COP) kuncike ezintweni ezimbili:

• idijithi kanambambili (Z) we indaba anode,
• electron amandla.

Ngo kakhulu x-ray amashubhu njengendlela material we anode esetshenziswa tungsten inombolo kabani le-athomu ilingana 74. Ngaphezu Z enkulu, lokhu metal unezinye izici ezithile ezenza kube efanelekayo le njongo. Tungsten uhlukile ngokuqondene namandla ayo silondoloze amandla lapho evuthayo, has a high ukuma kanye ongaphakeme ukuhwamuka izinga.

Kwaphela iminyaka eminingi, le anode senziwa of tungsten okumsulwa. Eminyakeni yamuva, saqala ukusebenzisa lolu ingxubevange lensimbi rhenium, kodwa kuphela nje phezulu. Self anode Ngaphansi nje kwalolo ngwengwezi tungsten-rhenium eyenziwe impahla ukukhanya, ukushisa-USB. izinto ezimbili ezifana kukhona molybdenum futhi graphite.

I tube-X-ray esetshenziselwa mammography, yenziwe anode, kwagcwala molybdenum. Lokhu kwaziswa inenombolo Lesisemkhatsini-athomu (Z = 42), okudala izinhlayiyana eziningi zokukhanya nge isici amandla, efanelekayo ukuqopha esifubeni. Amanye amadivayisi mammography futhi abe anode yesibili, kwakhiwa kusukela steel (Z = 45). Lokhu kwenza kube nokwenzeka ukwandisa amandla futhi sifinyelele Ukungena enkulu khona amabele obukhulu.

Ukusetshenziswa ingxubevange tungsten-rhenium ngcono eside emisebeni okukhipha - namadivayisi isikhathi kahle nge anode eyenziwe tungsten okumsulwa kuyehla ngenxa umonakalo ezishisayo kuya ebusweni.

Iningi anode has ukuma akwazi ukugcina tapered futhi eqondiswa kushaft motor, okuyinto uzungeza kubo ngesivinini kuqhathaniswa okusezingeni eliphezulu ngesikhathi ekushayweni X-ray. Injongo ukujikeleza - ukususwa ukushisa.

indawo eqondile

I-X-ray isizukulwane ingxenye hhayi yonke anode. Senzeka endaweni encane ubuso bayo - endaweni eqondile. Ubukhulu zokugcina kunqunywa ubukhulu ugongolo electron ivela cathode. umumo unxande Ngo iningi it has kuyahlukahluka ngaphakathi amadivayisi mm 0.1-2.

I x-ray tube design nge usayizi ezithile endaweni eqondile. Zincane kangaka, ngaphansi ezinyakazayo ukufiphala kanye nokucija ephakeme, futhi ngaphezu kwalokho, ngcono ukushabalalisa ukushisa.

I-Focal usayizi indawo kuyisici okumelwe icatshangelwe lapho ukhetha tube-X-ray. Abakhiqizi ukukhiqiza amadivayisi nge indawo encane ebalulekile, lapho kuyadingeka ukufeza isinqumo high nemisebe sincane ngokwanele. Ngokwesibonelo, kuyadingeka ekuhloleni izingxenye ezincane futhi usentekenteke zomzimba njengoba e mammography.

I tube-X-ray ikakhulukazi ukukhiqiza izindawo ebalulekile nge osayizi ezimbili - ezinkulu nezincane, okungase akhethwe opharetha ngokuhambisana isithombe ukwakha inqubo.

cathode

Umsebenzi oyinhloko we-cathode - ukukhiqiza ama-electron kanye lokuqoqa wawayisa ugongolo iqondiswe anode. It ngokuvamile siqukethe wire Kuvunguza ezincane (intambo) ezishumekwe ikhefu inkomishi emise.

Electron edabula wesifunda angeke ngokuvamile ashiye umqhubi futhi ushiye isikhala. Nokho, bakwazi ukukwenza, uma zithola amandla anele. Kwenye inqubo eyaziwa ngokuthi ekushayweni ezishisayo, ukushisa wasebenzisa ukuba axoshe electron kusukela cathode. Lokhu kwenzeka uma umfutho i bashiye x-ray tube ifinyelela 10 ^-6 -10 ^-7 Torr. Art. I ntambo ukufuthelana ngendlela efanayo njengoba Kuvunguza intambo isibani ngu ngidlula therethrough zamanje. Umsebenzi cathode ray tube kuhambisana ngokubeka amalahle lokushisa luminescence ukufuduka energy ezishisayo therefrom electron.

ibhaluni

I anode futhi cathode eziqukethwe zezindlu uphawu - isilinda. Ibhaluni nokuqukethwe avamise ukubizwa ngokuthi i faka, okuyinto has a ukuphila elinganiselwe futhi ungayithola enye. I tube x-ray ngokuvamile ube isibani ingilazi, nakuba kube nensimbi futhi Ceramic amasilinda esetshenziselwa ezinye izinhlelo zokusebenza.

Umsebenzi oyinhloko ukusekela esitsheni nesizungu we anode kanye cathode, nokugcina cleaner. Ingcindezi ku bashiye x-ray tube at 15 ° C 1.2 × 10 ^-3 Pa. Ukuba khona igesi ethangini ezongenza ugesi ukuze egeleza idivayisi ngokukhululekile, singagcini nje ngokumlingisa ngesikushoyo ifomu ye-ugongolo-electron.

izindlu

-X-ray tube apharathasi yokuthi, ngaphezu ebiyelwe kanye nokwesekwa nezinye izingxenye, siwulimi umzimba isihlangu zidla ngemisebe, ngaphandle ugongolo ewusizo edabula iwindi. Indawo yayo elikhulu zangaphandle dissipates iningi ukushisa kule divayisi. Isikhala phakathi igobolondo kanye faka ligcwele uwoyela enikeza ukwahlukanisa kanye lwaluyophola ke.

chain

Isifunda kagesi uxhuma ifoni emthombeni wamandla, okuthiwa i-generator. Umthombo kunikwe amandla kunethiwekhi futhi oguqula wamanje kushintshana ukuqondisa zamanje. I generator futhi ikuvumela ukuba ulungise ezinye kwemigomo iketango:

• KV - voltage noma engaba kagesi;
• MA - zamanje ogeleza udlule tube;
• S - ubude noma ukuchayeka isikhathi, e kukhishwa nezingxenyana ezithile ngomzuzwana.

Isifunda inikeza ukuhamba electron. Basuke icala amandla, edabula generator, futhi ninike lona anode. Njengoba ukunyakaza kwabo kwenzeka kugucuka ezimbili:

• amandla kagesi ezingaba iguqulwe ibe energy kinetic;
• kinetic, yona, aguqulwa-X-ray ngemisebe ukushisa ku.

ezingaba

Lapho ama-electron, ukufika umfuma, they possess ezingaba energy kagesi, okuyinto kunqunywa inani KV voltage phakathi anode kanye cathode. I tube-X-ray wahlinzwa ngesikhathi voltage ukukhiqiza 1 KV okuyinto kuyizinhlayiyana ngamunye kufanele 1 Kev. Ngokulungisa KV, opharetha unika electron ngamunye ethile namandla.

kinetics

ingcindezi okuphansi i bashiye x-ray tube (at 15 ° C kuba 10 ^-6 -10 ^-7 Torr. V.) Ivumela uhlelo izinhlayiya ngaphansi isenzo ekushayweni futhi amakheli ndawonye amandla kagesi asebenza ezintweni ezivela cathode kuya anode. La mandla enza umzimba ngesivinini kubo, okuholela ngesivinini anda energy kinetic futhi ukwehla ezingaba khona. Lapho nezinhlayiya ihlala phezu anode, ekuthuthukeni kwayo kulahleka, nawo onke amandla ayo is ibe energy kinetic. 100-Kev electron ifinyelela ngesivinini esingaphezu kwengxenye isivinini ukukhanya. Yashaya ebusweni kuyizinhlayiyana kuyehla ngokushesha kakhulu futhi ulahlekelwe amandla abo kinetic. Uphendukela X-ray noma ukushisa.

Electron mbeni athomu ngalinye impahla anode. Kushisa bhé kule ndawo eyenziwe ekusebenzelaneni kwabo nge orbitals (-X-ray izinhlayiyana eziningi zokukhanya), kanye ne-core (bremsstrahlung).

ngibopha amandla

Ngamunye electron e-athomu has a amandla athile esibophezelayo, okuyinto incike ubukhulu yokugcina kanye ezingeni lapho kuyizinhlayiyana itholakala. Amandla ngibopha udlala indima ebalulekile isizukulwane isici X ray nakuma-kuyadingeka ukuze ususe electron kusukela athomu.

bremsstrahlung

Bremsstrahlung ukhiqiza abaningi kakhulu izinhlayiyana eziningi zokukhanya. Amaelectrons ukungena impahla anode nokwelula eduze nucleus, baphambukile futhi decelerated okudonsa amandla athomu. amandla abo elahlekile phakathi kulo mhlangano livela ngesimo-X-ray-albhamu yezithombe.

uhla

Kuphela izinhlayiyana eziningi zokukhanya ezimbalwa une-vala amandla ukuze amandla electron. Iningi lawo ke ingaphansi. Ucabange ukuthi kukhona isikhala noma ensimini ezizungezile nengaphakathi lapho ama-electron, isipiliyoni amandla "okusithiyayo." Le nkambu zingahlukaniswa zibe esishintshashintshayo. Lokhu kunikeza umbono core ensimini kuyi-athomu ye target maphakathi. Electronic falling kuphi ilitshe decelerated futhi yakha i-albhamu yezithombe-X-ray. Izinhlayiyana iwe ukuthi esiseduzane isikhungo, bavezwa kakhulu futhi ngenxa yalokho balahlekelwa amandla kakhulu, ikhiqiza kakhulu ephezulu amandla izinhlayiyana eziningi zokukhanya. Electron engena indawo engaphandle ibhekene nokuxhumana ababuthakathaka futhi ukhiqize izinhlayiyana eziningi zokukhanya wamandla aphansi. Nakuba le ndawo kufanele ububanzi efanayo, ukuthi banayo indawo ehlukile kuye ngokuthi ibanga kusuka nucleus. Njengoba isibalo u-izinhlayiya ngesenzakalo zone, kuncike endaweni yayo Imininingwane, kusobala ukuthi endaweni yangaphandle uthwebule electron amaningi futhi zibangele izinhlayiyana eziningi zokukhanya ngaphezulu. amandla-X-ray spectrum kungenziwa wabikezela yilo imodeli.

E izinhlayiyana eziningi zokukhanya _max main bremsstrahlung spectrum elihambisana E-electron _max. Ngezansi leli phuzu, nge nokuncipha ikhasi lesikhwama sasekhaya amandla kwandisa isibalo sabo.

Inani elikhulu of izinhlayiyana eziningi zokukhanya energy ongaphakeme matasa noma elicwengekileyo, njengoba uzame idlule kobuso tube anode noma ibhokisi zokuhlunga. Ukuhlunga ngokuvamile sincike ukwakheka kanye ukushuba we impahla okuyothi ugongolo sihamba, futhi lokhu inquma ifomu yokugcina ephansi amandla spectrum ijika.

ithonya KV

I ephezulu amandla ingxenye spectrum inquma voltage x-ray amashubhu e kV (kilovolt). Lokhu kungenxa yokuthi inquma amandla electron ukufinyelela anode, futhi eziningi zokukhanya ayikwazi banekhono olukhulu kunalolu. Ngaphansi iyiphi voltage ukugijima-X-ray tube? Umkhawulo ikhasi lesikhwama sasekhaya amandla elivumelana isicelo ezingaba khona. Lokhu voltage ingahluka phakathi ukuchayeka ngenxa kushintshana kunethiwekhi yamanje. Kulokhu, E _max isiqongo voltage kunqunywa ikhasi lesikhwama sasekhaya oscillation isikhathi KV _p.

Ngaphezu kwalokho Quanta ezingaba, KV _p inquma inani emisebeni eyenziwe inani elithile electron ukufinyelela anode. Kusukela kahle Imininingwane emisebeni bremsstrahlung luyanda sigameko electron amandla ukwanda, okuyinto kunqunywa KV _p, lokhu kusho ukuthi _i-p-KV kuthinta nekusebenta idivayisi.

Ukushintsha KV _p, ngokuvamile ukushintsha bohlu. Le ndawo Imininingwane ngaphansi ijika amandla kumelela inani izinhlayiyana eziningi zokukhanya. spectrum unfiltered kuyinto unxantathu, kanye nenani emisebeni ngokulingana isikwele KV. Ephambi kwezinduna lemifanekiso kwandisa KV ukwanda Ukungena izinhlayiyana eziningi zokukhanya, okuyinto kunciphisa iphesenti emisebeni elicwengekileyo. Lokhu kuholela isivuno ngemisebe.

isici ngemisebe

Uhlobo nokuxhumana ukuthi edonsa emisebeni isici yakhiwa ngesivinini ukushayisana electrons esemkhathini. Ukuxhumana ungakwazi kuphela zenzeke lapho ingxenye E _we kuyizinhlayiyana has sikhulu kunesihlalo amandla yokubopha i-athomu. Lapho lesi sifo ukuhlangana khona, kukhona ukushayisana, electron is akhishwe. Lokhu kushiya isikhundla evulekile, zizogcwaliswa kuyizinhlayiyana ephakeme energy level. Njengoba siqhubekela electron unika amandla sasikhipha ngesimo-X-ray-albhamu yezithombe. Ibizwa ngokuthi isici ngemisebe, kusukela E yiyona i-albhamu yezithombe isici chemical isici kusuka lapho anode senziwa. Ngokwesibonelo, lapho i-electron is wangqongqoza K tungsten ungqimba _{mayelana no-=} 69,5 Kev, leso sikhala ligcwele i-electron kusukela _zokuxhumana L-level ne E = 10.2 Kev. Isici-X-ray ikhasi lesikhwama sasekhaya has alingana namandla umehluko phakathi amazinga ezimbili, noma 59,3 Kev.

Eqinisweni, indaba anode kuholela eziningi ezingavamile-X-ray amandla. Lokhu kwenzeka ngoba electron emazingeni ahlukahlukene amandla (K, L, njll) kungaba akhishwe bombarding izinhlayiya kanye izikhala nigcwaliswe ezihlukahlukene amazinga energy. Nakuba izikhala L-level edonsa izinhlayiyana eziningi zokukhanya namandla abo ezincane kakhulu ukuze isetshenziswe imaging zokuxilonga. Ngamunye amandla isici unikezwa ukuqokwa okhombisa esemkhathini, lapho ukuzalisa isikhundla, ne-index elibonisa umthombo electron edingekayo. -alpha (α) isho Inkomba ngokugcwalisa electron kusukela L-level, ne-beta (β) likhombisa ukugcwaliswa ezingeni M noma N.

• Spectrum tungsten. Emisebeni sici metal ukhiqiza spectrum komugqa ehlanganisa amandla eziningana ezehlukene nokuhlale unyathela amabhuleki, edonsa ukusatshalaliswa okuqhubekayo. Isibalo izinhlayiyana eziningi zokukhanya adalwe ngamunye amandla isici, ungachazwa ukuthi ematfuba ukugcwalisa isikhala K-level incike esemkhathini.
• Spectrum molybdenum. Anodes lokhu metal esetshenziselwa mammography, ukukhiqiza ezimbili ngokwanele okukhulu isici x-ray amandla: K-alpha at 17,9 Kev kanye K-beta 19.5 Kev. Ububanzi elikhulu-X-ray amashubhu, okuvumela ukuba sifinyelele ibhalansi engcono phakathi ukwahlukana ngemisebe umthamo ngoba isilinganiso usayizi webele luzuzwe E _p = 20 Kev. Nokho Bremsstrahlung ukukhiqiza amandla. Ngo imishini mammography zokususa izingxenye engadingeki bohlu esetshenziswa molybdenum zokuhlunga. Lemifanekiso usebenza isimiso «K-onqenqemeni." It ubamba emisebeni e-electron ngokweqile ngibopha amandla ngesikhathi K-level molybdenum athomu.
• Nomkhakha we steel. Rhodium has isethi yemiphumela 45, futhi molybdenum - 42. Ngako-ke, isici X-ray of a anode steel uzoba namandla kancane kunakunoma molybdenum futhi angena kakhudlwana. Isetshenziselwa ezithwetshuliwe amabele obukhulu.

Anodes nge ebusweni izindawo double, molybdenum, steel, amandla ama-opharetha ukuze ukhethe ukusatshalaliswa elungiselelwe amabele angusayizi ohlukile kanye kwabantu.

Umthelela on the KV bohlu

KV ukubaluleka kuthinta kakhulu emisebeni isici, isb. K. Ngeke ekhiqizwa uma KV kancane K-energy level electron. Lapho KV idlula lesi silinganiso nombundu, inani emisebeni eyingozi kuba sezingeni ngokuvamile wakhona umehluko umbundu KV tube KV.

Nomkhakha zamandla izinhlayiyana eziningi zokukhanya ka-X-ray ugongolo asebenza ezintweni ezivela kudivayisi kunqunywa izici eziningana. Njengomthetho, liphethe bremsstrahlung futhi isici nokuxhumana.

Ukwakheka isihlobo bohlu incike anode impahla, KV kanye lemifanekiso. Ngo ngamapayipi nge tungsten anode ekushayweni isici is hhayi kwakhiwa ngaso KV <69,5 Kev. Ngezinye nezinombolo ka hf elisetshenziswa izifundo zokuxilonga, isici emisebeni kwandisa emisebeni Imininingwane ku-25%. Amadivayisi molybdenum kungase kufinyelelwe ingxenye enkulu yesamba ugcogce umthamo.

ukusebenza kahle

Kuphela ingxenye encane amandla ayikhululwa electron iguqulwe ibe ngemisebe. Ingxenyana main amuncwa umzimba futhi iguqulwe ibe ukushisa. kahle emisebeni lichazwa ngokuthi ingxenyenamba wenani Babechichima amandla kusukela kagesi jikelele wanginika anode. Izinto enquma nekusebenta tube-X-ray zisetshenziswa voltage KV futhi idijithi kanambambili Z.-ratio eseduze kokulandelayo:

• Ukuphumelela = KV x Z x 10 ^-6.

Ubudlelwano obuphakathi kahle futhi KV kunomphumela ethize ekusetshenzisweni esiwusizo sokuba nezinto eziqondile imishini-X-ray. Ngenxa ukushisa isizukulwane tube abe nomkhawulo wenombolo kwamandla kagesi bakwazi ukudamba. It ziwumthwalo anoma umkhawulo wedivayisi. Nokho, okwandisa KV, lemali emisebeni ezivezwa omunye ukushisa kakhulu kwandisa.

Ukwencika nekusebenta isizukulwane-X-ray phezu yokwakheka anode kuphela nesithakazelo okufunda ngenxa namadivayisi amaningi asetshenziswa tungsten. Okungabalulwa molybdenum futhi steel, elisetshenziswa mammogram. Ukuphumelela alamathuluzi kakhulu aphansi tungsten ngenxa yokuthi isibalo sabo aphansi athomu.

ukusebenza

Ukuphumelela-X-ray tube kuchazwa njengoba inani ngemisebe millirentgenah zilethwe iphuzu maphakathi ugongolo ewusizo at ibanga 1 m kusuka endaweni ebalulekile ngayinye 1 Mas electron edabula kudivayisi. Inani layo limelela ikhono idivayisi ukuguqula amandla we izinhlayiya icala e emisebeni-X-ray. It ikuvumela ukuba ukunquma ukuchayeka esiguli, futhi isithombe. Njengoba kahle, kahle zedivayisi kuxhomeke ezicini eziningana, kuhlanganise KV, ifomu voltage igagasi, indaba anode futhi izinga lomonakalo ebusweni kudivayisi lemifanekiso isikhathi ukusetshenziswa.

KV- ukuphathwa

Voltage KV-X-ray tube ngempumelelo elawula emisebeni okukhiphayo. Njengomthetho, kucatshangwa ukuthi wokukhipha wakhona esigcawini KV. Doubling KV ukuchayeka kwandisa izikhathi 4.

umumo gagasi

I umumo gagasi uchaza indlela ngawo KV siyahlukahluka ngesikhathi isizukulwane emisebeni ngenxa yesimo eyindilinga kwamandla. Ezisetshenzisiwe waveforms eziningana ezahlukene. Isimiso jikelele: ezincane ushintsho KV ukuma, emisebeni-X-ray ikhiqizwa kahle. Imishini yesimanje esetshenziswa ugesi nge KV kuqhathaniswa njalo.

-X-ray amashubhu: Abakhiqizi

Oxford Instruments Inkampani ekhiqiza imishini ehlukahlukene, kuhlanganise ingilazi, amandla 250 W, 4-80 kV ezingaba, lo ebalulekile endaweni 10 microns futhi anhlobonhlobo anode izinto, t. H. Ag, Au, Co, Kr, Cu, Fe, Mo, pd, RH, Ti, W.

Varian inikeza kuka 400 izinhlobo ezahlukene zokwelapha nezezimboni-X-ray amashubhu. Okunye abakhiqizi ezaziwa kukhona Dunlee, GE, Philips, Shimadzu, Siemens, Toshiba, IAE, Hangzhou Wandong, Kailong et al.

ERussia ekhiqizwa-X-ray amashubhu "USvetlana-Roentgen". Ngaphezu amadivayisi yendabuko nge ligijima kanye nenkampani anode umile silwenza kumadivayisi we cathode abandayo ecucuza elikhanyayo elawulwa. Izinzuzo kumadivayisi alandelayo:

• ukusebenza izindlela okuqhubekayo nokushaya kwenhliziyo;
• ukungabikho inertia;
• olawula ukushuba LED zamanje;
• ubumsulwa spectrum;
• kungenzeka-X-ray emisebeni okujula obuhlukahlukene.