Iterambere mu ikoranabuhanga rikoresha urumuri rwa ultraviolet rukabije

Iterambere mu miterere y'imirasire y'urumuri ikabijeikoranabuhanga rikoresha urumuri

Mu myaka ya vuba aha, amasoko menshi ya harmonic ya ultraviolet yakuruye abantu benshi mu bijyanye n'imikorere ya electron bitewe n'uko ihuza neza, igihe gito cy'umutima n'ingufu nyinshi za photon, kandi byakoreshejwe mu bushakashatsi butandukanye bwa spectral na image. Bitewe n'iterambere ry'ikoranabuhanga, ibiisoko y'urumuriIri gutera imbere rigana ku nshuro nyinshi zo gusubiramo, flux nyinshi ya fotoni, ingufu nyinshi za fotoni n'ubugari bugufi bw'amajwi. Iri terambere ntirinongera gusa ubushobozi bwo gupima amasoko y'urumuri rwa ultraviolet rukabije, ahubwo rinatanga amahirwe mashya ku iterambere ry'ikoranabuhanga mu gihe kizaza. Kubwibyo, kwiga byimbitse no gusobanukirwa isoko y'urumuri rwa ultraviolet rukabije rugaruka kenshi ni ingenzi cyane mu kumenya no gukoresha ikoranabuhanga rigezweho.

Ku bipimo bya electron spectroscopy ku bipimo by'igihe cya femtosecond na attosecond, umubare w'ibintu bipimwa mu rumuri rumwe akenshi ntuba uhagije, bigatuma amasoko y'urumuri ruto asubiramo inshuro nyinshi adahagije kugira ngo haboneke imibare yizewe. Muri icyo gihe, isoko ry'urumuri rifite flux nke ya photon izagabanya igipimo cy'urusaku hagati y'ibimenyetso bya microscope mu gihe gito cyo kwigaragaza. Binyuze mu bushakashatsi n'igerageza rihoraho, abashakashatsi bakoze byinshi mu kunoza umusaruro no gukwirakwiza urumuri rwa ultraviolet rusubiramo inshuro nyinshi. Ikoranabuhanga rigezweho ryo gusesengura spectral hamwe n'isoko ry'urumuri rwa ultraviolet rusubiramo inshuro nyinshi ryakoreshejwe kugira ngo hagerwe ku gupima neza imiterere y'ibikoresho n'imikorere y'ikoranabuhanga.

Gukoresha amasoko y'urumuri rwa ultraviolet rukabije, nka electron spectroscopy (ARPES) yafashwe na angular resolved electron, bisaba urumuri rwa ultraviolet rukabije kugira ngo rumurikire icyitegererezo. Electron ziri ku buso bw'icyitegererezo zishishikazwa n'urumuri rwa ultraviolet rukabije, kandi ingufu za kinetic n'ingufu za fotoelectron zikubiyemo amakuru y'imiterere y'icyitegererezo. Electron analyzer ifite function ya Angle resolution yakira fotoelectron zarashwe kandi ikabona imiterere y'icyitegererezo hafi y'icyitegererezo cya valence. Ku nshuro nke zo gusubiramo, isoko y'urumuri rwa ultraviolet rukabije, kubera ko pulse yayo imwe irimo fotoni nyinshi, izakurura fotoelectron nyinshi ku buso bw'icyitegererezo mu gihe gito, kandi imikoranire ya Coulomb izazana kwaguka gukomeye kw'ikwirakwizwa ry'ingufu za fotoelectron kinetic, byitwa space charge effect. Kugira ngo tugabanye ingaruka z'ingaruka za space charge, ni ngombwa kugabanya fotoelectron ziri muri buri pulse mugihe ukomeza flux ya foton ihoraho, bityo ni ngombwa gutwaralaserhamwe n'inshuro nyinshi zo gusubiramo kugira ngo habeho urumuri rwinshi rwa ultraviolet rufite inshuro nyinshi zo gusubiramo.

Ikoranabuhanga ryo kongera ubushobozi bwo gupima imiterere y'amajwi (Resonance) rituma habaho uburyo bwo gupima imiterere y'amajwi ku buryo bwo hejuru ku buryo bwo gusubiramo MHz.
Kugira ngo babone isoko ry'urumuri rwa ultraviolet rukabije rufite umuvuduko wo gusubiramo kugeza kuri 60 MHz, itsinda rya Jones ryo muri Kaminuza ya British Columbia mu Bwongereza ryakoze umushinga wo guteranya urumuri rw'urumuri mu buryo bworoshye mu buryo bwa femtosecond resonance enhancement cavity (fsEC) kugira ngo bagere ku isoko ry'urumuri rwa ultraviolet rufatika kandi barukoresheje mu igerageza rya electron spectroscopy (Tr-ARPES) ryafashwe na time-resolved. Isoko ry'urumuri rishobora gutanga flux ya fotoni irenga 1011 kuri segonda hamwe na harmonic imwe ku muvuduko wo gusubiramo wa 60 MHz mu rwego rw'ingufu kuva kuri 8 kugeza kuri 40 eV. Bakoresheje sisitemu ya laser ya fiber doped ytterbium nk'isoko y'imbuto kuri fsEC, kandi bagenzura imiterere ya pulse binyuze mu gishushanyo cya sisitemu ya laser yihariye kugira ngo bagabanye urusaku rw'umuvuduko wa carrier envelope offset (fCEO) no kugumana imiterere myiza ya pulse ku mpera y'umuyoboro wa amplifier. Kugira ngo bagere ku kongera imbaraga mu buryo buhamye muri fsEC, bakoresha imiyoboro itatu yo kugenzura imikorere ya servo mu kugenzura ibitekerezo, bigatuma habaho gutuza ku rugero rubiri rw'ubwisanzure: igihe cyo kugaruka mu gusimbuka kw'amajwi muri fsEC gihuye n'igihe cyo gusimbuka kwa laser, n'impinduka mu gice cy'amashanyarazi ugereranije n'ibahasha y'amajwi (ni ukuvuga, ibahasha y'amajwi, ϕCEO).

Bakoresheje gaze ya krypton nk'umwuka ukora, itsinda ry'abashakashatsi ryageze ku gukora harmonics zo mu rwego rwo hejuru muri fsEC. Bakoze ibipimo bya Tr-ARPES bya grafiti kandi babona ko thermiation yihuta ndetse no kongera guhindagurika buhoro buhoro kw'ama-electron adashyushye cyane, ndetse n'imikorere y'ibintu bidashyushye cyane hafi y'urwego rwa Fermi ruri hejuru ya 0.6 eV. Iyi soko y'urumuri itanga igikoresho cy'ingenzi cyo kwiga imiterere y'ibikoresho bigoye. Ariko, gukora harmonics zo mu rwego rwo hejuru muri fsEC bifite ibisabwa byinshi byo kugarura urumuri, gupima gutatana, guhindura neza uburebure bw'aho hantu no gufunga aho hantu, bizagira ingaruka cyane ku kongera imbaraga z'aho hantu hashyushye cyane. Muri icyo gihe, igisubizo cy'urwego rudahuje n'umurongo wa plasma ku gice cy'ibanze cy'aho hantu nacyo ni ikibazo. Kubwibyo, ubu bwoko bw'urumuri ntibwabaye ultraviolet ikomeye cyane.isoko y'urumuri rufite harmonic nyinshi.