TW class attosecond X-ray pulse laser

TW class attosecond X-ray pulse laser
Attosecond X-raymem tes lasernrog lub zog siab thiab lub sijhawm luv mem tes yog tus yuam sij kom ua tiav ultrafast nonlinear spectroscopy thiab X-ray diffraction imaging. Pab neeg tshawb fawb hauv Tebchaws Meskas tau siv lub cascade ntawm ob-theemX-ray dawb electron laserskom tso zis discrete attosecond pulses. Piv nrog rau cov ntawv ceeb toom uas twb muaj lawm, qhov nruab nrab lub zog siab ntawm cov pulses yog nce los ntawm qhov kev txiav txim ntawm qhov loj, qhov siab tshaj plaws lub zog yog 1.1 TW, thiab lub zog nruab nrab yog ntau tshaj 100 μJ. Txoj kev tshawb no tseem muab pov thawj muaj zog rau kev coj tus cwj pwm zoo li solitone superradiation hauv X-ray.High-zog laserstau tsav ntau qhov chaw tshiab ntawm kev tshawb fawb, suav nrog kev ua haujlwm siab physics, attosecond spectroscopy, thiab laser particle accelerators. Ntawm txhua hom lasers, X-rays tau siv dav hauv kev kuaj mob, kuaj pom qhov tsis zoo, kev tshuaj xyuas kev nyab xeeb thiab kev tshawb fawb tshawb fawb. X-ray dawb-electron laser (XFEL) tuaj yeem ua rau lub siab X-ray lub zog los ntawm ntau qhov kev txiav txim ntawm qhov loj dua piv rau lwm cov X-ray tiam thev naus laus zis, yog li txuas ntxiv daim ntawv thov X-rays rau thaj tsam ntawm nonlinear spectroscopy thiab ib leeg- particle diffraction imaging qhov twg siab zog yuav tsum tau. Qhov kev vam meej attosecond XFEL tsis ntev los no yog qhov ua tiav loj hauv attosecond science thiab thev naus laus zis, ua kom muaj lub zog siab tshaj plaws los ntawm ntau dua rau qhov kev txiav txim siab ntawm qhov loj dua piv rau cov khoom siv X-ray.

Dawb electron laserstuaj yeem tau txais lub zog pulse ntau qhov kev txiav txim siab ntau dua li qib emissions spontaneous siv cov kev tsis sib haum xeeb, uas yog tshwm sim los ntawm kev cuam tshuam tsis tu ncua ntawm cov hluav taws xob hluav taws xob hauv cov kab hluav taws xob sib txuas thiab cov hlau nplaum oscillator. Nyob rau hauv qhov nyuaj X-ray ntau (txog 0.01 nm txog 0.1 nm wavelength), FEL tau ua tiav los ntawm cov khoom ntim compression thiab cov txheej txheem tom qab saturation coning. Hauv qhov muag xoo hluav taws xob (li 0.1 nm txog 10 nm wavelength), FEL yog siv los ntawm cascade tshiab-slice technology. Tsis ntev los no, attosecond pulses nrog lub siab tshaj plaws lub zog ntawm 100 GW tau tshaj tawm tias tau tsim los siv txoj kev txhim kho tus kheej-amplified spontaneous emission (ESASE).

Pab neeg tshawb fawb tau siv ob-theem amplification system raws li XFEL los ua kom nrov X-ray attosecond mem tes tso zis los ntawm linac coherent.qhov kajmus rau theem TW, ib qho kev txiav txim ntawm qhov loj hlob ntawm kev txhim kho ntau tshaj qhov tau tshaj tawm cov txiaj ntsig. Qhov kev sim teeb tsa tau pom nyob rau hauv daim duab 1. Raws li ESASE txoj kev, lub photocathode emitter yog modulated kom tau ib tug electron beam nrog ib tug siab tam sim no spikes, thiab yog siv los tsim attosecond X-ray pulses. Tus mem tes pib yog nyob rau pem hauv ntej ntawm tus ntsia hlau loj ntawm cov nqaj hlau electron, raws li qhia nyob rau sab laug sab sauv ntawm daim duab 1. Thaum XFEL ncav cuag saturation, lub nqaj hluav taws xob tau ncua sij hawm txheeb ze rau X-ray los ntawm cov hlau nplaum compressor, thiab tom qab ntawd cov mem tes cuam tshuam nrog lub teeb hluav taws xob (cov hlais tshiab) uas tsis hloov kho los ntawm ESASE modulation lossis FEL laser. Thaum kawg, tus thib ob sib nqus undulator yog siv los txuas ntxiv rau X-rays los ntawm kev sib cuam tshuam ntawm attosecond pulses nrog cov hlais tshiab.

FIG. 1 Cov duab kos duab sim; Cov duab qhia tau hais tias qhov chaw nyob ntev (lub sij hawm-zog daim duab ntawm lub electron, ntsuab), qhov profile tam sim no (xiav), thiab cov hluav taws xob tsim los ntawm thawj qhov kev txiav txim siab amplification (ntsuab). XTCAV, X-band transverse kab noj hniav; cVMI, coaxial ceev daim ntawv qhia qhov system; FZP, Fresnel band phaj spectrometer

Tag nrho cov pulses attosecond yog tsim los ntawm lub suab nrov, yog li txhua tus mem tes muaj qhov sib txawv spectral thiab lub sij hawm-sau lub zog, uas cov kws tshawb fawb tau tshawb fawb ntau ntxiv. Nyob rau hauv cov nqe lus ntawm spectra, lawv siv Fresnel band phaj spectrometer los ntsuas lub spectrum ntawm ib tug neeg pulses ntawm txawv sib npaug undulator lengths, thiab pom tias cov spectra tuav du waveforms txawm tias tom qab theem nrab amplification, qhia tias pulses tseem unimodal. Nyob rau hauv lub sij hawm sau, lub angular fringe yog ntsuas thiab lub sij hawm domain waveform ntawm lub mem tes yog characterized. Raws li pom hauv daim duab 1, X-ray pulse yog sib tshooj nrog lub voj voog polarized infrared laser mem tes. Lub photoelectrons ionized los ntawm X-ray mem tes yuav tsim streaks nyob rau hauv cov kev taw qhia opposite rau vector peev xwm ntawm lub infrared laser. Vim hais tias lub teb hluav taws xob ntawm lub laser tig nrog lub sij hawm, lub zog faib ntawm lub photoelectron yog txiav txim los ntawm lub sij hawm ntawm electron emission, thiab kev sib raug zoo ntawm lub angular hom ntawm lub sij hawm emission thiab lub zog faib ntawm lub photoelectron yog tsim. Kev faib tawm ntawm photoelectron momentum yog ntsuas siv lub coaxial ceev daim ntawv qhia spectrometer. Raws li kev faib tawm thiab cov txiaj ntsig spectral, lub sij hawm-domain waveform ntawm attosecond pulses tuaj yeem rov tsim dua. Daim duab 2 (a) qhia txog kev faib cov mem tes ntev, nrog qhov nruab nrab ntawm 440 li. Thaum kawg, lub tshuab ntsuas roj tau siv los ntsuas lub zog ntawm cov mem tes, thiab cov phiaj xwm tawg ntawm lub siab pulse zog thiab lub sijhawm mem tes raws li qhia hauv daim duab 2 (b) tau suav. Peb qhov kev teeb tsa sib raug rau cov kab hluav taws xob sib txawv ntawm cov teeb pom kev zoo, cov xwm txheej tsis sib xws thiab sib nqus compressor ncua sijhawm. Peb qhov kev teeb tsa tau ua rau lub zog nruab nrab ntawm 150, 200, thiab 260 µJ, feem, nrog lub siab tshaj plaws lub zog ntawm 1.1 TW.

Daim duab 2. (a) Distribution histogram of half-height Full width (FWHM) pulse duration; (b) Scatter zajlus sib raug rau lub zog siab tshaj plaws thiab lub sijhawm mem tes

Tsis tas li ntawd, txoj kev tshawb no kuj tau pom thawj zaug ntawm qhov tshwm sim ntawm soliton-zoo li superemission nyob rau hauv X-ray band, uas tshwm sim raws li ib tug tas mus li mem tes shortening thaum lub sij hawm amplification. Nws yog tshwm sim los ntawm kev sib cuam tshuam ntawm cov hluav taws xob thiab hluav taws xob muaj zog, nrog lub zog nrawm nrawm ntawm electron mus rau lub taub hau ntawm X-ray pulse thiab rov qab mus rau electron los ntawm tus Tsov tus tw ntawm lub mem tes. Los ntawm kev kawm tob ntawm qhov tshwm sim no, nws xav tias X-ray pulses nrog lub sijhawm luv dua thiab lub zog siab dua tuaj yeem paub ntxiv los ntawm kev nthuav dav cov txheej txheem superradiation amplification thiab ua kom zoo dua ntawm pulse shortening hauv soliton-zoo li hom.