Monga machubu X-ray ntchito?

X-ray ndi kwaiye akatembenuka mphamvu ya ma elekitironi kuti photons, lomwe limapezeka mu X-ray chubu. Kuchuluka (kukhudzana) ndi khalidwe (sipekitiramu) cheza zikhoza kusintha ndi kusintha pano, voteji ndi nthawi ya chida cha.

Mfundo ntchito

X-ray machubu (chithunzi anapatsidwa m'nkhani) ndi mphamvu converters. Iwo azilandire izo kwa maukonde ndi n'kukhala mitundu ina - ozama cheza ndi kutentha, yotsirizira ndi osafunika byproduct. X-ray chubu chipangizo moti maximizes yopanga photons ndi dissipates kutentha mwamsanga.

Chubu ndi chipangizo osavuta, amangoona kupanga zinthu zosiyana kwambiri - ndi cathode ndi anode. Pamene panopa umayenda kuchokera cathode kuti anode, ndi ma elekitironi kutaya mphamvu, imbaenda ku m'badwo wa X-ray.

anode

The anode ndi chigawo chimodzi, mmene umuna wa photons mkulu-mphamvu umatulutsa. Izi ndi ndi yaikulu zitsulo chinthu chimene chikugwirizana ndi mzati zabwino za dera magetsi. Zikuyenera ntchito ziwiri:

• Iwo otembenuka elekitironi mphamvu mu X-ray poizoni
• Iwo dissipates kutentha.

The mfundo anode ndi amusankha kuti tizikonda ntchitozo.

Choncho, ambiri a ma elekitironi ayenera kupanga photons mkulu-mphamvu, osati kutentha. Pali wa mphamvu yonse, amene n'kukhala X-cheza (wapolisi) kumatengera zifukwa ziwiri:

• atomiki chiwerengero (Z) nkhani anode,
• elekitironi mphamvu.

Mu kwambiri machubu x-ray monga chuma cha anode ntchito tungsten, amene atomiki nambala wofanana 74. Kuwonjezera pa Z lalikulu, zitsulo imeneyi ili makhalidwe ena ndipo izi zimapangitsa abwino kwa cholinga ichi. Tungsten ndi wapadera umatha kukhala mphamvu pamene mkangano, ali mkulu limatsogolera mfundo ndi mtengo wochepa evaporation.

Kwa zaka zambiri, anode unapangidwa tungsten koyera. M'zaka zaposachedwapa, tinayamba ntchito aloyi zitsulo ndi rhenium, koma padziko. Self anode pansi pa tungsten-rhenium ❖ kuyanika opangidwa ndi nsalu kuwala, chabwino kutentha yosungirako. zinthu ziwiri amenewa ndi molybdenum ndi graphite.

The X-ray chubu ntchito mammography, wopangidwa ndi anode ndi TACHIMATA ndi molybdenum. Nkhanizi ali mungafike atomiki chiwerengero (Z = 42), amene amapanga photons ndi mphamvu khalidwe, oyenera kujambula pachifuwa. Ena zipangizo mammography amakhalanso anode chachiwiri, anapanga kuchokera rhodium (Z = 45). Izi zimathandiza kuwonjezera mphamvu ndi kukwaniritsa malowedwe kwambiri mabere wandiweyani.

Ntchito tungsten-rhenium aloyi bwino cheza yaitali linanena bungwe - ndi zipangizo nthawi Mwachangu ndi anode zopangidwa tungsten koyera yafupika chifukwa kuwonongeka matenthedwe pamwamba.

Ambiri anode ali ndi mawonekedwe a zimbale tapered ndi kuliika kwa galimoto kutsinde, yomwe imazungulira iwo imathamanga ndi mkulu nthawi ya umuna wa X-ray. Cholinga cha kuzungulira kwa - kuchotsa kutentha.

focal banga

The X-ray m'badwo gawo osati anode lonse. Kumachitika mu malo aang'ono a padziko - malo focal. Makulidwe otsiriza anatsimikiza kukula kwa elekitironi mtengo akubwera kuchokera cathode lapansi. Mu ambiri ali ndi amakona anayi mawonekedwe zimasiyanasiyana mwa 0.1-2 zipangizo mm.

Chubu kapangidwe x-ray ndi kukula wina wa malo wofunika. Zing'onozing'ono ndi, chindichepere zoyenda blur ndi sharpness apamwamba, nanga zambiri, ndi bwino kutentha madyaidya ndikuledzera.

Mogwirizana malo kukula ndi chimene tiyenera kuziganizira posankha X-ray chubu. Opanga kubala zipangizo ndi yaing'ono focal malo, kumene kuli koyenera kuti tikwaniritse kusamvana mkulu ndi zazing'ono cheza zokwanira. Mwachitsanzo, chofunika mu kafukufuku wa mbali yaing'ono yowawitsa ya thupi monga mammography.

The X-ray chubu makamaka kubala mawanga mogwirizana ndi zamitundu iwiri - yaikuluikulu, sipangakhalenso osankhidwa ndi woyendetsa mu malinga ndi chithunzi kupanga ndondomeko.

cathode

Ntchito yaikulu ya cathode wa - kupanga ma elekitironi ndi kusonkhanitsa iwo mu mtengo walangizidwa anode lapansi. Aliyense imakhala yaing'ono mwauzimu waya (filament) ophatikizidwa mu recess chikho woboola pakati.

Ma elekitironi kudutsa dera sangathe bwinobwino kusiya kondakitala ndi kusiya malo ufulu. Komabe, iwo akhoza kuchita izo, ngati iwo mphamvu zokwanira. Mu ndondomeko yodziwika monga umuna ikukhudzana kutentha ntchito kuchotsa ma elekitironi ku cathode lapansi. Izi imatheka pamene kuthamanga mu anasamutsidwa x-ray chubu ukufika 10 ^-6 -10 ^-7 Torr. Art. thonje ndi usavutike mu mofanana mwauzimu filament nyale ndi kudutsa ndi therethrough panopa. Ntchito cathode ray chubu limodzi ndi Kutentha ndi kutentha luminescence kusamutsidwa matenthedwe mphamvu therefrom ma elekitironi lapansi.

zibaluni

The anode ndi cathode zili mu nyumba womata - yamphamvu. The zibaluni ndi nkhani zake nthawi zambiri amatchedwa Ikani ndi lomwe lili ndi moyo malire ndipo akhoza m'malo. The x-ray chubu zambiri babu galasi, ngakhale zitsulo ndi ceramic zonenepa ntchito zina ofunsira.

The Ntchito yaikulu ndi kuthandiza chidebe ndi kudzipatula kwa anode ndi cathode, ndi kukhalabe kuyamwa. Kuthamanga mu anasamutsidwa x-ray chubu pa 15 ° C ndi 1.2 × 10 ^-3 Pa. Kupezeka kwa mafuta m'galimoto adzalola magetsi kuyenda kupyolera chipangizo mtima wonse, osati mu mawonekedwe a elekitironi mtengo.

nyumba

X-ray chubu zida yoteroyo kuti, kuwonjezera pa mpanda ndi thandizo la zigawo zina, ali ngati chishango thupi ndipo zimatenga cheza, koma kwa mtengo zothandiza kudutsa zenera. Ake ndi lalikulu kunja pamwamba dissipates kwambiri kutentha kwaiye mu chipangizo. Danga pakati pa chipolopolo ndi Ikani uli wodzazidwa ndi mafuta amene amapereka kutchinjiriza ndi yozizira izo.

tcheni

Dera magetsi zikugwirizana foni kuti gwero mphamvu, wotchedwa jenereta. Gwero ali zoyendetsedwa kwa maukonde ndi otembenuka alternating panopa kulongosola panopa. Jenereta komanso amalola kusintha zina magawo a unyolo:

• KV - voteji kapena kuthekera magetsi;
• MA - panopa umene ukufika mwa chubu;
• S - nthawi kapena padzuwa nthawi, mu tuzigawo twa a lachiwirilo.

dera zimathandiza gulu la ma elekitironi. Iwo ali ndi udindo mphamvu, kudutsa jenereta, ndi kuupereka kwa anode lapansi. Monga gulu lawo amapezeka masinthidwe awiri:

• magetsi mphamvu ingathandize n'kukhala mphamvu kayendedwe;
• kayendedwe, nayenso ali n'kukhala X-ray cheza ndi kutentha.

kuthekera

Pamene ma elekitironi kufika mu botolo, iwo adzalandira kuthekera mphamvu ngati zamagetsi, amene anatsimikiza ndi kuchuluka kwa KV voteji pakati pa anode ndi cathode. The X-ray chubu opaleshoni pa voteji kuti kupanga 1 KV umene aliyense tinthu ayenera 1 keV. Ndi kusintha KV, ndi woyendetsa amapatsa aliyense elekitironi ndi kuchuluka mphamvu.

kinetics

Low kuthamanga mu anasamutsidwa x-ray chubu (pa 15 ° C ndi 10 ^-6 -10 ^-7 Torr. V.) amalola particles pansi zochita za umuna ndi thermionic magetsi mphamvu panamveka ku cathode kuti anode lapansi. mphamvu Iyamba iwo, chifukwa kuchuluka liwiro ndi mphamvu kayendedwe ndi atsikira angathe. Pamene tinthu zikugwera pa anode ndi, umatha atayika, ndi onse a mphamvu yake n'kukhala mphamvu kayendedwe. 100-keV elekitironi kufika liwiro lalikulu kuposa theka liwiro kuwala. Kupanda pamwamba pa tinthu ndi liwiro msanga kwambiri ndi kutaya mphamvu zawo kayendedwe. Fatsa ndi X-ray kapena kutentha.

Ma elekitironi amakhudzana ndi maatomu munthu wa chuma anode. Cheza kwaiye zikuyendera mogwirizana ndi orbitals (X-ray photons), ndi pakati (bremsstrahlung).

kumanga mphamvu

Aliyense elekitironi mu atomu ali ndi ena kumangako mphamvu, potsata kukula kwa otsiriza ndi mlingo pa zimene tinthu ndi ili. The mphamvu kumanga amagwira ntchito yofunika kwambiri mu m'badwo wa khalidwe X-ray ndipo ankafunika kuchotsa ndi elekitironi ku atomu.

bremsstrahlung

Bremsstrahlung ambabala chiwerengero chachikulu cha photons. The ma elekitironi kudutsa mu zinthu anode Ndi m'mithunzi pafupi phata la, anapanduka ndi decelerated yokoka mphamvu atomu. mphamvu zawo anataya pa msonkhano uno limapezeka mu mawonekedwe a X-ray fotoni.

osiyanasiyana

Only ndi photons ochepa ndi pafupi mphamvu kwa mphamvu elekitironi. Ambiri a iwo ndi m'munsi. Kuganiza kuti pali danga kapena munda ozungulira pachimake, mmene ma elekitironi zinachitikira mphamvu "chopinga." Pofunika akhoza kugawidwa m'zigawo. Ichi chimapereka Polingalira za m'munda pakati pa chandamale atomu pakati. Pakompyuta kugwa paliponse chandamale ndi decelerated ndipo amapanga ndi X-ray fotoni. Tinthu amene amagwa pafupi ndi pakati, amapezeka poyera choncho kutaya mphamvu kwambiri popanga kwambiri photons mkulu-mphamvu. Ma elekitironi adalowa zone lakunja akukumana ndi anzake ofooka ndi kupanga photons mphamvu m'munsi. Ngakhale dera m'lifupi chomwecho, kuti iwo ali ndi malo osiyanasiyana malingana ndi mtunda kuchokera phata la. Popeza chiwerengero cha particles zinachitika pa woyendera nthambi, zimadalira malo ake okwana, n'zoonekeratu kuti malo kunja kugwila ma elekitironi ndi chifukwa photons kwambiri. mphamvu X-ray sipekitiramu akhoza yotsutsana ndi chitsanzo ichi.

E _Max photons waukulu bremsstrahlung sipekitiramu lolingana E _Max ma elekitironi. Pansipa mfundo imeneyi, ndi kucheperachepera fotoni mphamvu kumawonjezera chiwerengero chawo.

A nambala yaikulu ya photons mphamvu otsika odzipereka kapena osasankhidwa, ngati iwo amafuna kudutsa padziko anode chubu kapena bokosi fyuluta. Zosefera zambiri amadalira zikuchokera ndi makulidwe a nkhani imene mtengo chitadutsa, ndipo izi ndiyo mawonekedwe chomaliza cha otsika mphamvu sipekitiramu limaoneka lokongola.

chikoka KV

Mkulu-mphamvu mbali sipekitiramu wa ndiyo voteji x-ray machubu mu kV (kilovolt). Ichi ndi chifukwa ndiyo mphamvu ya ma elekitironi kufika anode, ndi photons simungakhoze kukhala ndi kuthekera zazikulupo kuposa izi. Ngakhale voteji kuthamanga X-ray chubu? The pazipita fotoni mphamvu limafanana ndi pazipita ntchito kuthekera. voteji Izi zingasiyane pa kukhudzana chifukwa alternating maukonde panopa. Pankhaniyi, E _Max pachimake voteji anatsimikiza mtima fotoni oscillation nthawi KV _p.

Komanso angathe quanta, KV _tsa Mzimuyo kuchuluka cheza kwaiye chiwerengero anapatsidwa wa ma elekitironi kufika anode. Popeza Mwachangu okwana cheza bremsstrahlung ndi chinawonjezeka ndi chochitika elekitironi ukuwonjezeka mphamvu, amene anatsimikiza KV _tsa, amatanthauzanso kuti KV _tsa kumakhudzanso Mwachangu chipangizo.

Kusintha KV _tsa, kawirikawiri kusintha sipekitiramu. Malo okwana pansi pa pamapindikira mphamvu akuimira chiwerengero cha photons. Unfiltered sipekitiramu ndi kansalu, ndi kuchuluka cheza yolingana ndi lalikulu KV. Pamaso pa sefa Komanso kumawonjezera KV kuwonjezeka malowedwe a photons, omwe amachepetsa kuchuluka cheza ndi osasankhidwa. Zimenezi zimabweretsa kuchuluka cheza zokolola.

cheza khalidwe

Mtundu wa mogwirizana kuti amapanga ndi cheza khalidwe limapangidwa mkulu-liwiro kugunda ndi ma elekitironi yozungulira. Mogwirizana zitha kutenga malo pamene gawo E Nyerere _ali wamkulu kuposa mphamvu kumanga atomu. Pamene chikhalidwe ichi anakumana, ndipo pali kugunda, elekitironi ndi kugonja. Zimenezi zitanthauza malo lotseguka, wodzazidwa ndi tinthu apamwamba mlingo mphamvu. Monga ife kusuntha elekitironi amapereka mphamvu panamveka mu mawonekedwe a X-ray fotoni. Njirayi imatchedwa cheza khalidwe, kuyambira E ndi fotoni khalidwe mankhwala mchitidwe imene anode wapangidwa. Mwachitsanzo, pamene elekitironi ndi anagogoda K tungsten wosanjikiza _mogwirizana ndi E = 69,5 keV, Kusoweka ladzala ndi elekitironi ku _kulankhulana L mlingo ndi E = 10,2 keV. Khalidwe X-ray fotoni ali mphamvu wofanana ndi kusiyana pakati zimatiyika awiri, kapena 59,3 keV.

Ndipotu anode zinthu kumabweretsa angapo khalidwe mphamvu X-ray. Izi zimachitika chifukwa ma elekitironi misinkhu yosiyanasiyana mphamvu (K, L, etc.) angathe anagogoda bombarding particles ndi wantchito wa kutinso mudzazidwe ndi zosiyanasiyana milingo mphamvu. Ngakhale wantchito L mlingo amapanga photons ndi mphamvu zawo ndi ang'ono kwambiri ntchito matenda kulingalira. Aliyense mphamvu khalidwe wapatsidwa lakuti omwe akusonyeza yozungulira, mmene ndi Kusoweka, ndi index amene amaonetsa elekitironi gwero chofunika. Alpha (α) akutanthauza index chodzaza elekitironi ku L mlingo, ndi beta (β) limasonyeza kudzazidwa mlingo wa M kapena N.

• Sipekitiramu tungsten. The cheza khalidwe la zitsulo kumachititsanso sipekitiramu liniya wopangidwa mwa mphamvu angapo apawokha ndi braking amapanga yogawa mosalekeza. chiwerengero cha photons analengedwa ndi chilichonse mphamvu khalidwe, yodziwika kuti Mwina nadzaza Kusoweka K-mlingo zimadalira yozungulira.
• Sipekitiramu molybdenum. Anodes chitsulo ichi ntchito mammography mubale awiri mokwanira kwambiri khalidwe x-ray mphamvu: K-Alpha pa 17,9 keV ndi K-beta pa 19,5 keV. The momwe akadakwanitsira osiyanasiyana machubu X-ray, amene amalola kuti tikwaniritse bwino bwino pakati Mosiyana ndi walitsa mlingo kwa pafupifupi kukula kwa mawere akwaniritsa pa E _tsa = 20 keV. Komabe Bremsstrahlung kutulutsa mphamvu zambiri. Zipangizo mammography kochotsa mbali osafunika wa sipekitiramu ntchito molybdenum fyuluta. Sefa ntchito pa mfundo za «K-m'mphepete." Iwo zimatenga cheza mu elekitironi owonjezera kumanga mphamvu pa K-mlingo molybdenum atomu.
• The sipekitiramu wa rhodium. Rhodium ali atomiki nambala 45, ndipo molybdenum - 42. Choncho khalidwe X-ray wa rhodium anode adzakhala ndi mphamvu pang'ono kuposa wa molybdenum ndi zambiri zopweteka mmakutu. Izo ntchito kulingalira mabere wandiweyani.

Anodes ndi madera awiri pamwamba, molybdenum, rhodium, chimathandiza woyendetsa kusankha yogawa ndi wokometsedwa kwa mabere a kukula osiyana ndi osalimba.

Zotsatira pa sipekitiramu KV

KV mtengo kwambiri amakhudza cheza khalidwe, mwachitsanzo. K. sizidzasungidwa opangidwa ngati zochepa KV mlingo K-mphamvu ma elekitironi. Pamene KV kuposa phindu ili pakhomo, kuchuluka cheza zambiri njila kwa kusiyana ndi kuloŵa KV chubu KV.

The mphamvu sipekitiramu wa photons ya X-ray mtengo panamveka kwa chipangizo anatsimikiza ndi zifukwa zingapo. Monga ulamuliro, izo tichipeza bremsstrahlung ndi anzake khalidwe.

The zikuchokera wachibale wa sipekitiramu chimadalira pa nkhani anode, KV ndi fyuluta. Mu chubu ndi tungsten anode khalidwe umuna si anapanga pa KV <69,5 keV. Pa mfundo apamwamba HF ntchito maphunziro matenda cheza khalidwe kumawonjezera cheza okwana 25%. Zipangizo molybdenum mwina kufika gawo lalikulu la okwana ikuyambitsa mphamvu.

Mwachangu

Mbali yaing'ono chabe ya mphamvu anakamba ndi ma elekitironi ndi n'kukhala cheza. Kachigawo yaikulu ndi odzipereka ndipo n'kukhala kutentha. Mwachangu cheza limanenedwa ngati kachigawo chiweruzo ankalankhula mphamvu yochokera kwa magetsi ambiri poona anode. Zinthu zomwe kudziwa Mwachangu ya X-ray chubu chagwiritsidwa voteji KV ndi atomiki chiwerengero Z. The pafupifupi chiŵerengero cha zotsatirazi:

• Mwachangu = KV × Z x 10 ^-6.

Kubverana Mwachangu ndi KV kumakhudza zenizeni pa kugwiritsa ntchito zida X-ray. Chifukwa kutentha m'badwo wa chubu ndi malire pa chiwerengero cha mphamvu ya magetsi kuti iwo akhoza dissipate. Iwo amaika pa mphamvu ya malire chipangizo. Ndi kukula KV Komabe, kuchuluka cheza opangidwa ndi chimodzi cha kutentha kwambiri kumawonjezera.

The kudalira kwa dzuwa la m'badwo X-ray pa zikuchokera anode uli kokha chidwi maphunziro chifukwa zipangizo kwambiri ntchito tungsten. Zosiyana ndi molybdenum ndi rhodium, ntchito mammogram lapansi. Mwachangu mwa zipangizozi ndi kwambiri m'munsi kwa tungsten chifukwa cha chiwerengero chawo m'munsi atomiki.

mogwira

Mwachangu X-ray chubu limanenedwa ngati kuchuluka kwa walitsa millirentgenah kwa mfundo pakati pa mtengo zothandiza pa mtunda wa 1 mita kuchokera pamalo focal lililonse 1 mAs ma elekitironi kudutsa chipangizo. phindu lake likuimira luso chipangizo kutembenuza mphamvu particles mlandu ndi X-ray cheza. Timatha kudziwa padzuwa la wodwalayo, ndi chithunzithunzi. Monga dzuwa, dzuwa chipangizo kumatengera zifukwa zambiri, kuphatikizapo KV, ndi voteji yoweyula mawonekedwe, ulusi anode ndi digiri ya kuwonongeka pamwamba pa chipangizo fyuluta ndi nthawi ya ntchito.

KV-kasamalidwe

Voteji KV X-ray chubu bwino akulamulira cheza linanena bungwe. Monga ulamuliro, amaganiza kuti linanena bungwe ndi njila kwa lalikulu la KV lapansi. Anawaonjezera kuwirikiza kawiri KV kukhudzana kumawonjezera nthawi 4.

waveform

The waveform limafotokoza njira imene KV zimasiyanasiyana ndi nthawi m'badwo wa poizoni chifukwa chikhalidwe ozungulira mphamvu. Ntchito angapo waveforms osiyana. Mfundo ambiri: ang'onoang'ono kusintha KV mawonekedwe, ndi X-ray cheza amapangidwa mosabvuta. Zipangizo zamakono ntchito magudumu ndi KV ndi zonse.

machubu X-ray: Opanga

Oxford Zida Company manufactures zipangizo zosiyanasiyana, kuphatikizapo galasi, mphamvu 250 W, 4-80 kV kuthekera, inali pamalo 10 microns ndi osiyanasiyana zipangizo anode, T. H. AG, Au, Co, Kr, Cu, Fe, Mo, PD, uchembere wabwino, Ti, W.

Varian amapereka 400 osiyanasiyana machubu zachipatala ndi mafakitale X-ray. alimi ena amadziwika ndi Dunlee, Ge, Philips, Shimadzu, Siemens, Toshiba, IAE, Hangzhou Wandong, Kailong neri Al.

Mu Russia opangidwa X-ray machubu "Svetlana-Roentgen". Kuwonjezera zipangizo chikhalidwe ndi onsewo ndi n'kupuma anode kampani manufactures zipangizo kuzizira cathode wowala kamwazi ankalamulira. Ubwino zipangizo zotsatirazi:

• ntchito yothandizira ndi zimachitika modes;
• pakalibe inertia;
• malamulo mphamvu ya LED panopa;
• sipekitiramu chiyero;
• kuthekera X-ray cheza cha kusinthasintha kwambiri.