X-rays

X-rays tau sab los ntawm cov WK Roentgen nyob rau hauv 1895 thiab muaj npe lub X-rays. Nyob rau lub ob xyoos tom ntej, ib tus paub txog kev koom tes nyob rau hauv lawv cov kev tshawb fawb. Thaum lub sij hawm lub sij hawm no, tus thawj raug tsim X-ray hlab. Lawv yog cov feem ntau qhov chaw ntawm hluav taws xob.

Nws tau raug qhia hais tias lub zog X-rays yuav tau txeem ib tug ntau yam ntawm cov ntaub ntawv, raws li tau zoo raws li mos mos tib neeg cov ntaub so ntswg. Cov yav tas qhov tseeb sai sai pom daim ntawv thov nyob rau hauv cov tshuaj.

Tus foundations ntawm X-rays ntes tau thaum cov xim zaum ib ncig ntawm lub ntiaj teb no. Cov nram qab no tom qab lawv discovery, lub loj loj nyiaj ua hauj lwm rau lawv txoj kev kawm thiab siv luam tawm.

Muaj ntau zaum kawm lub thaj chaw ntawm X-rays.

J .. Stokes kwv yees lawv electromagnetic xwm, nws tau raug paub tseeb hais tias experimentally Charles Barkley, uas kuj qhib thiab polarization. German physicists Knipping, Friedrich, Laue diffraction qhia (qhov tshwm sim nrog rau lub sib txawv los ntawm rectilinear hais tawm). Nyob rau hauv 1913, lub ywj siab los ntawm txhua lwm yam thiab Bragg Wolfe sab ib tug yooj yim kev sib raug zoo ntawm cov wavelength, diffraction kaum sab xis thiab qhov kev ncua deb ntawm neighboring atomic dav hlau nyob rau hauv lub siv lead ua. Tag nrho cov saum toj no ua hauj lwm tsim lub hauv paus ntawm cov yam ntxwv X-ray tsom xam. Siv cov spectra rau elemental tsom xam ntawm cov ntaub ntawv uas pib nyob rau hauv lub 20s. Nyob rau hauv txoj kev loj hlob ntawm txoj kev kawm thiab daim ntawv thov ntawm hluav taws xob ua si ib tug loj luag hauj lwm Physico-Technical lub koom haum, uas yog founded A. F. Ioffe.

Feem ntau qhov chaw beam yog ib tug X-ray raj. Txawm li cas los, cov kev pab tej zaum yuav ib tug neeg tej isotopes. Yog li ib tug ncaj qha emit X-rays, thiab lwm yam nuclear tawg (a-hais los yog electrons) emitting tawg bombard cov hlau lub hom phiaj. Lub raj muaj ib tug tshuam ntau dua tawg siv tshaj qhov isotopic qhov chaw. Nyob rau tib lub sij hawm, loj, me, nqi, qhov hnyav ntawm isotopic qhov chaw deb tsawg tshaj nrog lub installation raj.

Qhov chaw ntawm mos X-ray tej zaum yuav synchrotrons thiab hluav taws xob drives. Cov kev siv ntawm lub synchrotron tawg ntawm ob los yog peb kev txiav txim ntawm qhov ntau ntau dua tshaj tawg raj rau hauv lub chav ntawm ib tug cheeb tsam.

Lub ntuj qhov chaw, uas emit X-rays muaj xws li lub hnub thiab lwm yam khoom nyob rau hauv lub cosmos.

Nyob rau hauv raws li cov mechanism ntawm tshwm sim ntawm emission spectra lawv tus kheej tej zaum yuav yam ntxwv (kav) thiab nres (tas mus li).

Nyob rau hauv lub thib ob cov ntaub ntawv, X-ray spectrum tawm txim liab los ntawm lub ceev ceev hais (them) tshuav rau lawv inhibition nyob rau hauv tus txheej txheem ntawm kev sis raug zoo nrog lub hom phiaj atoms.

Kab emission yog generated raws li ib tug tshwm sim ntawm atomic ionization nrog electron ncaws los ntawm ib tug ntawm cov neeg zoo li ntawm lub atom. Qhov no tshwm sim tej zaum yuav ib tug rau txim ntawm ib tug kev sib tsoo, thiab ceev ceev atom hais, piv txwv li, nrog rau ib qho electron (thawj X-rays), los yog atom haum ntawm ib tug photon (fluorescence X-rays).

Sis rays nrog teeb meem muaj peev xwm tsim ib tug photoelectric nyhuv uas accompanies lawv haum los yog dissipation. Qhov no tshwm sim yog kuaj nyob rau hauv lub rooj plaub uas tus haum ntawm ib tug photon nrog ib tug atom emits ib tug ua ntej ib tug ntawm lub puab electrons. Nws yuav ces tshwm sim yog radiative hloov nrog emission ntawm cov yam ntxwv atom photon emission los yog ncaws tawm ntawm ib tug thib ob electron nyob rau hauv radiationless hloov.

Nyob rau hauv tus ntawm ib tug X-ray siv lead ua nonmetallic (e.g., pob zeb ntsev) nyob rau hauv ib co ntshav nyob rau hauv lub atomic lattice ntawm ions tsim, muaj ib tug ntxiv zoo xwb, thiab nyob ze lawv los muaj ntau heev electrons.