TW chav kawm attosecond X-ray pulse laser

TW chav kawm attosecond X-ray pulse laser
Attosecond X-raylaser mem tesnrog lub zog siab thiab lub sijhawm luv luv yog qhov tseem ceeb rau kev ua tiav ultrafast nonlinear spectroscopy thiab X-ray diffraction imaging. Pab pawg tshawb fawb hauv Tebchaws Meskas tau siv cov txheej txheem ntawm ob theemCov lasers hluav taws xob tsis muaj hluav taws xob X-raykom tso tawm cov pulses attosecond sib cais. Piv nrog cov ntawv ceeb toom uas twb muaj lawm, lub zog nruab nrab ntawm cov pulses tau nce ntxiv los ntawm qhov kev txiav txim ntawm qhov loj, lub zog siab tshaj plaws yog 1.1 TW, thiab lub zog nruab nrab yog ntau dua 100 μJ. Txoj kev tshawb fawb kuj muab cov pov thawj muaj zog rau tus cwj pwm zoo li soliton hauv thaj teb X-ray.Cov lasers muaj zog heevtau tsav ntau qhov chaw tshawb fawb tshiab, suav nrog kev tshawb fawb siab heev, attosecond spectroscopy, thiab laser particle accelerators. Ntawm txhua hom lasers, X-rays siv dav hauv kev kuaj mob, kev tshawb pom qhov tsis zoo hauv kev lag luam, kev tshuaj xyuas kev nyab xeeb thiab kev tshawb fawb. Lub X-ray free-electron laser (XFEL) tuaj yeem ua rau lub zog X-ray siab tshaj plaws ntau dua li lwm cov thev naus laus zis tsim X-ray, yog li txuas ntxiv kev siv X-rays mus rau thaj chaw ntawm nonlinear spectroscopy thiab ib leeg-particle diffraction imaging qhov twg xav tau lub zog siab. Lub attosecond XFEL ua tiav tsis ntev los no yog qhov ua tiav loj hauv kev tshawb fawb thiab thev naus laus zis attosecond, ua rau lub zog siab tshaj plaws muaj ntau dua rau qhov kev txiav txim siab piv rau cov chaw X-ray benchtop.

Cov lasers hluav taws xob dawbtuaj yeem tau txais lub zog pulse ntau qhov kev txiav txim siab ntawm qhov loj dua li qib kev tso tawm spontaneous siv kev tsis ruaj khov, uas yog tshwm sim los ntawm kev sib cuam tshuam tas mus li ntawm lub tshav pob hluav taws xob hauv lub teeb hluav taws xob relativistic thiab lub oscillator magnetic. Hauv qhov nyuaj X-ray ntau yam (kwv yees li 0.01 nm txog 0.1 nm wavelength), FEL yog ua tiav los ntawm kev sib sau ua ke thiab cov txheej txheem post-saturation coning. Hauv qhov mos X-ray ntau yam (kwv yees li 0.1 nm txog 10 nm wavelength), FEL yog siv los ntawm cascade fresh-slice technology. Tsis ntev los no, attosecond pulses nrog lub zog siab tshaj plaws ntawm 100 GW tau tshaj tawm tias tau tsim los ntawm kev siv txoj kev txhim kho tus kheej-amplified spontaneous emission (ESASE).

Cov pab pawg tshawb fawb tau siv ob-theem amplification system raws li XFEL los ua kom lub zog ntawm X-ray attosecond pulse output los ntawm linac coherent.lub teeb cimus rau theem TW, qhov kev txhim kho loj dua li cov txiaj ntsig tau tshaj tawm. Kev teeb tsa sim tau pom hauv Daim Duab 1. Raws li txoj kev ESASE, lub photocathode emitter raug modulated kom tau txais lub teeb hluav taws xob nrog lub zog siab tam sim no, thiab siv los tsim cov attosecond X-ray pulses. Lub pulse pib nyob ntawm ntug pem hauv ntej ntawm lub spike ntawm lub teeb hluav taws xob, raws li pom hauv kaum sab laug saum toj ntawm Daim Duab 1. Thaum XFEL mus txog qhov saturation, lub teeb hluav taws xob raug ncua sijhawm piv rau X-ray los ntawm lub tshuab nqus hlau nplaum, thiab tom qab ntawd lub pulse cuam tshuam nrog lub teeb hluav taws xob (cov hlais tshiab) uas tsis tau hloov kho los ntawm ESASE modulation lossis FEL laser. Thaum kawg, lub undulator sib nqus thib ob yog siv los ua kom cov X-rays loj dua los ntawm kev cuam tshuam ntawm attosecond pulses nrog cov hlais tshiab.

DUAB 1 Daim duab qhia txog lub cuab yeej sim; Daim duab qhia txog qhov chaw ntev (daim duab qhia txog lub sijhawm-zog ntawm lub electron, ntsuab), qhov profile tam sim no (xiav), thiab qhov hluav taws xob tsim los ntawm thawj-txheej txheem amplification (ntshav). XTCAV, X-band transverse cavity; cVMI, coaxial rapid mapping imaging system; FZP, Fresnel band plate spectrometer

Txhua lub attosecond pulses yog tsim los ntawm suab nrov, yog li txhua lub pulse muaj cov yam ntxwv sib txawv ntawm spectral thiab lub sijhawm-domain, uas cov kws tshawb fawb tau tshawb nrhiav ntau ntxiv. Hauv cov ntsiab lus ntawm spectra, lawv tau siv Fresnel band plate spectrometer los ntsuas cov spectra ntawm cov pulses ib leeg ntawm qhov sib txawv ntawm undulator ntev, thiab pom tias cov spectra no tswj cov waveforms du txawm tias tom qab secondary amplification, qhia tias cov pulses tseem unimodal. Hauv lub sijhawm domain, lub angular fringe raug ntsuas thiab lub sijhawm domain waveform ntawm lub pulse yog tus cwj pwm. Raws li pom hauv Daim Duab 1, lub X-ray pulse yog overlapped nrog lub circularly polarized infrared laser pulse. Cov photoelectrons ionized los ntawm X-ray pulse yuav tsim cov streaks hauv qhov kev taw qhia rov qab rau lub vector potential ntawm infrared laser. Vim tias lub teb hluav taws xob ntawm lub laser tig nrog lub sijhawm, qhov kev faib tawm ntawm lub zog ntawm photoelectron yog txiav txim siab los ntawm lub sijhawm ntawm electron emission, thiab kev sib raug zoo ntawm hom angular ntawm lub sijhawm emission thiab qhov kev faib tawm ntawm lub zog ntawm photoelectron yog tsim. Qhov kev faib tawm ntawm photoelectron momentum yog ntsuas siv lub coaxial fast mapping imaging spectrometer. Raws li qhov kev faib tawm thiab spectral cov txiaj ntsig, lub sijhawm-domain waveform ntawm attosecond pulses tuaj yeem rov tsim dua. Daim duab 2 (a) qhia txog kev faib tawm ntawm lub sijhawm pulse, nrog rau qhov nruab nrab ntawm 440 li. Thaum kawg, lub tshuab ntsuas roj tau siv los ntsuas lub zog pulse, thiab daim phiaj xwm scatter ntawm lub zog pulse ncov thiab lub sijhawm pulse raws li pom hauv Daim duab 2 (b) tau suav. Peb qhov kev teeb tsa sib xws rau cov xwm txheej sib txawv ntawm electron beam focusing, waver coning thiab magnetic compressor delay conditions. Peb qhov kev teeb tsa tau muab qhov nruab nrab pulse energies ntawm 150, 200, thiab 260 µJ, feem, nrog rau lub zog siab tshaj plaws ntawm 1.1 TW.

Daim Duab 2. (a) Daim duab qhia txog kev faib tawm ntawm ib nrab qhov siab Qhov dav tag nrho (FWHM) lub sijhawm ntawm lub zog; (b) Daim duab qhia txog qhov tawg uas sib raug rau lub zog siab tshaj plaws thiab lub sijhawm ntawm lub zog

Ntxiv rau qhov ntawd, txoj kev tshawb fawb kuj tau pom thawj zaug qhov tshwm sim ntawm soliton-zoo li superemission hauv X-ray band, uas zoo li lub zog luv luv tas mus li thaum lub sijhawm amplification. Nws yog tshwm sim los ntawm kev sib cuam tshuam muaj zog ntawm electrons thiab hluav taws xob, nrog lub zog hloov pauv sai sai los ntawm electron mus rau lub taub hau ntawm X-ray pulse thiab rov qab mus rau electron los ntawm tus tw ntawm lub pulse. Los ntawm kev kawm tob txog qhov tshwm sim no, nws xav tias X-ray pulses nrog lub sijhawm luv dua thiab lub zog siab dua tuaj yeem ua tiav ntxiv los ntawm kev txuas ntxiv cov txheej txheem superradiation amplification thiab siv qhov zoo ntawm lub zog luv luv hauv hom soliton.