Laser-driven neutron sources could offer a promising alternative to those based on conventional accelerator technologies in delivering compact beams of high brightness and short duration.We examine this through particle-in-cell and Monte Carlo simulations that model,respectively,the laser acceleration of protons from thin-foil targets and their subsequent conversion into neutrons in secondary lead targets.Laser parameters relevant to the 0.5 PW LMJ-PETAL and 0.6-6 PW Apollon systems are considered.Owing to its high intensity,the 20-fs-duration 0.6 PW Apollon laser is expected to accelerate protons up to above 100 MeV,thereby unlocking efficient neutron generation via spallation reactions.As a result,despite a 30-fold lower pulse energy than the LMJ-PETAL laser,the 0.6 PW Apollon laser should perform comparably well both in terms of neutron yield and flux.Notably,we predict that very compact neutron pulses,of～10 ps duration and～100 μm spot size,can be released provided the lead convertor target is thin enough(～100 μm).These sources are characterized by extreme fluxes,of the order of 1023 n cm-2 s-1,and even ten times higher when using the 6 PW Apollon laser.Such values surpass those currently achievable at large-scale accelerator-based neutron sources(～1016 n cm-2 s-1),or reported from previous laser experiments using low-Z converters(～1018 n cm-2 s-1).By showing that such laser systems can produce neutron pulses significantly brighter than existing sources,our findings open a path toward attractive novel applications,such as flash neutron radiography and laboratory studies of heavy-ion nucleosynthesis.

B.Martinez;S.N.Chen;S.Bola?os;N.Blanchot;G.Boutoux;W.Cayzac;C.Courtois;X.Davoine;A.Duval;V.Horny;I.Lantuejoul;L.Le Deroff;P.E.Masson-Laborde;G.Sary;B.Vauzour;R.Smets;L.Gremillet;J.Fuchs

LULI-CNRS,CEA,UPMC Univ Paris 06:Sorbonne Université,Ecole Polytechnique,Institut Polytechnique de Paris,F-91128 Palaiseau Cedex,France;CEA,DAM,DIF,F-91297 Arpajon,France;Horia Hulubei National Institute of Physics and Nuclear Engineering,Bucharest-Magurele,Romania;CEA,DAM,CESTA,F-33114 Le Barp,France;Université Paris-Saclay,CEA,LMCE,91680 Bruyères-le-Chatel,France;LPP,Sorbonne Université,CNRS,Ecole Polytechnique,F-91128 Palaiseau Cedex,France

极端条件下的物质与辐射（英文）

[1]B.Martinez;S.N.Chen;S.Bola?os;N.Blanchot;G.Boutoux;W.Cayzac;C.Courtois;X.Davoine;A.Duval;V.Horny;I.Lantuejoul;L.Le Deroff;P.E.Masson-Laborde;G.Sary;B.Vauzour;R.Smets;L.Gremillet;J.Fuchs-.Numerical investigation of spallation neutrons generated from petawatt-scale laser-driven proton beams)[J].极端条件下的物质与辐射（英文）,2022(02):8-17

LMJ,PETAL,Apollon

Numerical,investigation,spallation,neutrons,generated,from,petawatt,scale,laser,driven,beams,Laser,sources,could,offer,promising,alternative,those,conventional,accelerator,technologies,delivering,compact,brightness,short,duration,We,examine,this,through,particle,cell,Monte,Carlo,simulations,that,model,respectively,acceleration,protons,thin,foil,targets,their,subsequent,conversion,into,secondary,lead,parameters,relevant,PW,systems,are,considered,Owing,its,intensity,fs,expected,accelerate,up,above,MeV,thereby,unlocking,efficient,generation,via,reactions,result,despite,fold,lower,energy,than,should,perform,comparably,well,both,terms,yield,Notably,predict,very,pulses,ps,spot,size,released,provided,convertor,enough,These,characterized,extreme,fluxes,order,even,times,higher,when,using,Such,values,surpass,currently,achievable,large,reported,previous,experiments,converters,By,showing,such,produce,significantly,brighter,existing,findings,open,path,toward,attractive,novel,applications,flash,radiography,laboratory,studies,heavy,nucleosynthesis

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