Mphamvu ya Photoelectric, Mphamvu ya Compton, ndi X-Rays
Pendauluan
Kumayambiriro kwa zaka za m'ma 20, zinthu zingapo zofunika kwambiri zinasintha kumvetsetsa kwathu za mtundu wa kuwala ndi zinthu zina. Zinthu zitatu zofunika kwambiri—mphamvu ya kuwala kwa dzuwa, mphamvu ya Compton, ndi ma X-ray—zinathandiza kwambiri pakukula kwa sayansi yamakono. Nkhaniyi ikambirana chilichonse mwa zinthuzi, momwe zinapezekera, ndi tanthauzo lake ndi ntchito zake mu sayansi ndi ukadaulo.
Mphamvu ya Photoelectric
Kupeza ndi Kumvetsetsa
Mphamvu ya kuwala kwa dzuwa inayamba kuwonedwa ndi Heinrich Hertz mu 1887 pamene anapeza kuti kuwala kwa ultraviolet kungayambitse magetsi pa ma electrode. Komabe, kufotokozera kokwanira kwa chiphunzitso sikunabwere mpaka Albert Einstein mu 1905. Einstein adanenanso kuti kuwala kumakhala ndi kuchuluka kwa mphamvu yotchedwa photons, yomwe imatha kutulutsa ma electron kuchokera pamwamba pa chitsulo ikalowa.
Malinga ndi chiphunzitso cha Einstein, mphamvu ya photon \(E\) imaperekedwa ndi equation:
\[ E = h\nu \]
kumene \( h \) ndi chosasintha cha Planck ndipo \( \nu \) ndi kuchuluka kwa kuwala. Pamene ma photon okhala ndi mphamvu yokwanira agunda pamwamba pa chitsulo, amatha kutulutsa ma elekitironi ngati mphamvu ya photon ndi yayikulu kuposa ntchito ya chitsulocho:
\[ h\nu = \phi + KE \]
kumene \( KE \) ndi mphamvu ya kinetic ya elektroni yotulutsidwa.
Kuyesera ndi Kutsimikizira
Robert Millikan adachita kafukufuku wosiyanasiyana pakati pa 1914 ndi 1916 kuti ayesere lingaliro la Einstein. Zotsatira zake zidatsimikizira chiphunzitso cha Einstein, kusonyeza kuti mphamvu ya photon imagwirizana mwachindunji ndi kuchuluka kwa kuwala ndipo sikudalira mphamvu ya kuwala.
Zotsatira ndi Mapulogalamu
Mphamvu ya kuwala kwa dzuwa imapereka umboni wolunjika wa mtundu wa kuwala kwa quantum ndi mawonekedwe ake a mafunde ndi tinthu tating'onoting'ono. Izi ndizofunikira kwambiri pakukula kwa ukadaulo monga ma photovoltaic ndi makamera a CCD. Mu ukadaulo wa kuwala kwa dzuwa, ma photon ochokera ku dzuwa amagwiritsidwa ntchito kutulutsa ma elekitironi mkati mwa zinthu za semiconductor, ndikupanga magetsi omwe angagwiritsidwe ntchito ngati gwero la mphamvu.
Zotsatira za Compton
Kupeza ndi Kumvetsetsa
Zotsatira za Compton zinapezeka ndi Arthur H. Compton mu 1923. Compton anaona kuti pamene ma X-ray agundana ndi ma free electron, kutalika kwa ma X-ray omwazikana kumakhala kotalika kuposa kutalika kwa ma X-ray oyambirira. Kusintha kumeneku kumadalira ngodya ya kufalikira ndipo sikungathe kufotokozedwa ndi chiphunzitso cha mafunde akale a kuwala.
Compton adapereka lingaliro lakuti kugundana pakati pa photon ya X-ray ndi elekitironi kuyenera kuonedwa ngati kugundana kosalala pakati pa tinthu tiwiri. Mphamvu ndi mphamvu zimasungidwa munjira iyi. Equation ya kusintha kwa kutalika kwa mafunde (komwe kumadziwika kuti kusintha kwa Compton) imaperekedwa ndi:
\[ \Delta \lambda = \lambda' – \lambda = \frac{h}{m_ec} (1 – \cos \theta) \]
Kumene:
– \( \lambda \) ndiye kutalika kwa mafunde koyambirira kwa ma X-ray.
– \( \lambda' \) ndi kutalika kwa mafunde a X-rays omwe ali omwazikana.
– \( h \) ndi mawu osasinthika a Planck.
– \( m_e \) ndi kulemera kwa elekitironi.
– \( c \) ndi liwiro la kuwala.
– \( \theta \) ndi ngodya yofalikira.
Kuyesera ndi Kutsimikizira
Compton adachita zoyeserera mwa kuunikira cholinga cha graphite ndi ma X-ray ndikuyesa kutalika kwa mafunde a ma X-ray omwe anali atafalikira. Zotsatira zake zidagwirizana ndi zomwe adalosera, zomwe zidapereka umboni wamphamvu wa chitsanzo cha ma photon ngati tinthu tating'onoting'ono tokhala ndi mphamvu komanso mphamvu.
Zotsatira ndi Mapulogalamu
Mphamvu ya Compton imatsimikizira mtundu wa tinthu ta ma photon ndipo imalimbitsa chiphunzitso cha quantum cha mphamvu yamagetsi. Chochitikachi chili ndi ntchito zofunika kwambiri mu zamankhwala ndi zakuthambo. Mu kujambula zamankhwala, mphamvu ya Compton imagwiritsidwa ntchito mu computed tomography (CT) kuti ipange zithunzi zapamwamba za thupi lamkati. Mu zakuthambo, mphamvu ya Compton imathandiza kumvetsetsa mphamvu ya kuwala kwa cosmic ndi kapangidwe ka nyenyezi.
X-ray
Kupeza ndi Kumvetsetsa
Ma X-ray anapezeka ndi Wilhelm Conrad Röntgen mu 1895. Röntgen anapeza kuti ma X-ray osaoneka amatha kulowa mu zinthu zolimba ndikupanga mithunzi pa mapepala ojambula zithunzi. Iye anatcha ma X-ray amenewa kuti “ma X-ray” chifukwa cha mtundu wawo wosadziwika.
Ma X-ray ndi mtundu wa ma radiation amagetsi okhala ndi mafunde afupiafupi kwambiri (0,01 mpaka 10 nanometers) komanso mphamvu zambiri. Amapangidwa pamene ma elekitironi amphamvu kwambiri agundana ndi chandamale chachitsulo, mwadzidzidzi amachepetsa liwiro lawo ndikutulutsa mphamvu mu mawonekedwe a ma photon a X-ray.
Makhalidwe ndi Mitundu
Pali mitundu iwiri ikuluikulu ya ma X-ray omwe amapangidwa:
– Ma X-ray Odziwika: Amapangidwa pamene ma elekitironi amabwezeretsa ma elekitironi omwe akusowa kuchokera ku zipolopolo zamkati mwa maatomu omwe akufuna, ndikupanga ma photoni a mafunde enaake.
– Bremsstrahlung X-rays: Amapangidwa pamene ma elekitironi amachedwa ndi mphamvu yamagetsi ya atomiki, zomwe zimapangitsa kuti mafunde a X-ray azitha kusinthasintha nthawi zonse.
Zotsatira ndi Mapulogalamu
Kupezeka kwa ma X-ray kwakhudza kwambiri magawo osiyanasiyana, makamaka sayansi ya zamankhwala ndi zida. Mu zamankhwala, ma X-ray amagwiritsidwa ntchito pozindikira matenda komanso kuchiza. X-ray radiography imalola kujambula kapangidwe ka mkati mwa thupi, kuthandiza madokotala kuzindikira kusweka kwa mafupa, zotupa, ndi matenda ena osiyanasiyana. Chithandizo cha radiation chimagwiritsa ntchito ma X-ray amphamvu kwambiri kuti awononge maselo a khansa.
Mu sayansi ya zinthu, ma X-ray amagwiritsidwa ntchito mu X-ray crystallography kuti adziwe kapangidwe ka atomu ndi mamolekyu a makristalo. Njira imeneyi ndi chida chofunikira kwambiri mu chemistry, biology, ndi sayansi ya zinthu, zomwe zimathandiza kuti Rosalind Franklin, James Watson, ndi Francis Crick apeze kapangidwe ka DNA.
Mapeto
Mphamvu ya kuwala kwa dzuwa, mphamvu ya Compton, ndi ma X-ray ndi zinthu zazikulu zomwe zatithandiza kumvetsetsa bwino za mtundu wa kuwala ndi zinthu zina. Mphamvu ya kuwala kwa dzuwa inasonyeza mtundu wa kuwala kwa quantum, mphamvu ya Compton inatsimikizira mphamvu ya ma photon, ndipo ma X-ray anatsegula maiko atsopano mu kujambula ndi kusanthula kapangidwe ka zinthu.
Kupezeka ndi kumvetsetsa zinthu zimenezi kwapangitsa kuti pakhale ukadaulo wambiri womwe wasintha kwambiri madera osiyanasiyana a sayansi ndi uinjiniya. Kuyambira kugwiritsa ntchito zamankhwala mpaka kafukufuku wa sayansi, mphamvu ya photoelectric, mphamvu ya Compton, ndi ma X-ray zikupitirizabe kugwira ntchito yofunika kwambiri pakupititsa patsogolo ukadaulo ndi chidziwitso cha anthu.
