Tsis ntev los no, cov kws tshawb fawb los ntawm University of Quebec tau ua qhov kev sim ua tiav ntawm Advanced Laser Light Source Laboratory ntawm National Research Council of Canada (INRS), ua qauv qhia kev cog lus siv ultrafast laser technology rau kev kho mob qog noj ntshav.
"Peb tau ua pov thawj thawj zaug tias nyob rau hauv qee qhov xwm txheej, lub teeb laser nruj nreem tsom rau ntawm huab cua puag ncig tuaj yeem ua kom cov hluav taws xob mus rau MeV (mega-electron volt) lub zog ntau yam, uas yog tib lub zog ib yam li qee lub tshuab hluav taws xob siv hauv hluav taws xob hluav taws xob. kev kho mob." hais tias Franois Légaré, INRS tus xibfwb thiab tus thawj coj tshawb fawb ntawm Lub Tsev Haujlwm Saib Xyuas Lub Teeb Tseem Ceeb (ALLS).
Los ntawm nruj tsom mus rau ntau lub voj voog ntawm millijoule (mJ)-theem, femtosecond (fs), infrared (IR) laser, cov kws tshawb fawb tsim cov kab hluav taws xob sib txuas hauv cov huab cua puag ncig thiab ua tiav cov koob tshuaj siab txog li 0.15 Grey per second (Gy/s). Ntawm atmospheric siab, lawv cov laser siv tau mus txog 1 × 1019 watts ib square centimeter (W/cm-2). Pab pawg tau ntsuas qhov tshwm sim ntawm cov kab hluav taws xob thiab pom tias nws muaj lub zog siab tshaj plaws txog li 1.4 MeV.
Pab neeg no tau pom tias yuav ua li cas lub laser lub teeb pom kev zoo, qhov ntev wavelength, thiab luv luv-lub voj voog mem tes ntev ua ke los txwv qhov cuam tshuam ntawm b-kev koom ua ke ntawm lub teeb tsom laser. Lub siab ceev ntawm huab cua molecules nyob rau hauv lub ionizable focal ntim yog txaus los tsim ib lub plasma ze rau qhov tseem ceeb ceev, uas muab ib tug siab conversion efficiency ntawm lasers rau electrons. Los ntawm peb-dimensional particle-in-cell simulations, cov kws tshawb fawb tau lees paub tias lub tshuab acceleration yog relativistically raws li, muaj ib tug loj-txoj kev muaj peev xwm, thiab yog theoretically raws li kev ntsuas electron energies thiab tawg.
Schematic ntawm kev sim teeb: pulses ntawm ultrashort infrared laser lub teeb yog nruj nreem tsom rau cov huab cua nyob ib puag ncig, ua ib tug high koob ntawm ionizing hluav taws xob.
Cov kws tshawb fawb ntseeg tias lub zog ntawm qhov laser-tsav hluav taws xob hluav taws xob no yog los ntawm nws txoj kev yooj yim. Ib qho kev tsom teeb pom kev zoo nyob rau hauv ib puag ncig huab cua tuaj yeem tsim hluav taws xob hluav taws xob uas xa tawm ib xyoos ntawm cov nqi hluav taws xob rau tus neeg sawv cev ib meter deb hauv tsawg tshaj li ib ob. Tsis muaj teeb meem nyuaj lossis lub tshuab nqus tsev yuav tsum tau ua, ua cov qauv no haum rau ntau daim ntawv thov irradiation los ntawm kev txo cov kev xav tau los tsim cov khoom siv hluav taws xob ultrafast MeV.
Kev nce qib hauv laser thev naus laus zis tau ua kom lub zog ua kom lub zog ntawm laser - cov txheej txheem uas ua kom cov hluav taws xob ua kom lub zog siab hauv lub sijhawm luv luv los ntawm kev tsim cov ntshav ntshav - ua haujlwm hauv nruab nrab-infrared nrog mJ-chav kawm systems los tsim cov particle fluxes ntawm MeV electrons. uas tuaj yeem siv rau hauv kev tshawb fawb radiobiology. Txawm li cas los xij, cov khoom siv hluav taws xob laser-tsav hluav taws xob no yuav tsum muaj kev sib txuas thiab loj hauv lub tshuab nqus tsev, uas txwv tsis pub nkag mus rau cov nqaj.
Laser-tsav MeV cov khoom siv hluav taws xob tuaj yeem muab txoj hauv kev tshiab rau kev kho mob qog noj ntshav, xws li FLASH radiation therapy, ib txoj hauv kev kho cov qog uas tiv taus cov pa hluav taws xob kho. Nrog kev kho FLASH, cov koob tshuaj hluav taws xob ntau tuaj yeem xa hauv microseconds es tsis txhob feeb. Qhov kev xa khoom ceev no pab tiv thaiv cov ntaub so ntswg noj qab haus huv nyob ib puag ncig cov qog los ntawm cov teebmeem ntawm hluav taws xob. Txawm hais tias qhov cuam tshuam ntawm FLASH tsis nkag siab tag nrho, cov kws tshawb fawb ntseeg tias FLASH tuaj yeem ua rau deoxygenation sai ntawm cov ntaub so ntswg noj qab haus huv, txo cov ntaub so ntswg rhiab heev rau hluav taws xob.
Kev ntsuas hluav taws xob ntsuas tus nqi (logarithmic scale) raws li kev ua haujlwm ntawm kev ncua deb ntawm qhov chaw focal rau peb lub zog sib txawv laser mem tes.
"Tsis muaj kev tshawb fawb tseem tsis tau piav qhia txog qhov tshwm sim ntawm cov nyhuv flash," tus kws tshawb fawb Simon Vallières tau hais tias, "Txawm li cas los xij, cov khoom siv hluav taws xob siv hauv FLASH hluav taws xob kho mob muaj cov yam ntxwv zoo ib yam li qhov peb tsim los ntawm kev tsom lub laser hnyav ntawm huab cua ambient. Thaum cov chaw hluav taws xob tswj tau zoo dua, cov kev tshawb fawb ntxiv yuav tso cai rau peb tshawb xyuas qhov ua rau lub zog flash thiab thaum kawg muab kev kho hluav taws xob zoo dua rau cov neeg mob qog noj ntshav. "
Cov kws tshawb fawb ntseeg tias qhov scalability ntawm lawv txoj hauv kev yuav nce ntxiv nrog kev txhim kho txuas ntxiv ntawm lub zog nruab nrab ntawm lub zog lasers hauv mJ chav kawm. Txoj kev loj hlob sai ntawm cov khoom siv laser, tsom mus rau qhov muaj zog ntawm cov mem tes thiab cov nqi rov ua dua, tuaj yeem tso cai rau INRS cov txheej txheem txuas mus rau cov hluav taws xob ntau dua thiab cov koob tshuaj ntau dua.
Cov kws tshawb fawb tseem tau hais txog qhov tseem ceeb ntawm kev nyab xeeb thaum cuam tshuam nrog cov kab teeb laser nruj nreem tsom rau cov huab cua ib puag ncig. Thaum kev ntsuas tau raug coj mus rau ib puag ncig ntawm qhov chaw hluav taws xob, pab pawg tau pom cov nqi hluav taws xob los ntawm cov hluav taws xob uas muaj peb mus rau plaub npaug ntau dua li cov kev siv hluav taws xob zoo li qub.
Vallières tau hais tias "Qhov pom lub zog ntawm cov hluav taws xob (MeV) tso cai rau lawv txav ntau dua 3 meters hauv huab cua lossis ob peb millimeters hauv qab ntawm daim tawv nqaij," uas ua rau muaj kev pheej hmoo ntawm hluav taws xob raug rau cov neeg siv lub teeb pom kev zoo. Qhov kev puas tsuaj hluav taws xob no yog lub sijhawm los ua kom muaj kev nyab xeeb dua hauv chav kuaj. "
