A tabletop, ultrashort pulse photoneutron source driven by electrons from laser wakefield acceleration  

作　　者：X.J.Jiao J.M.Shaw T.Wang X.M.Wang H.Tsai P.Poth I.Pomerantz L.A.Labun T.Toncian M.C.Downer B.M.Hegelich 

机构地区：[1]Center for High Energy Density Science,University of Texas,Austin,TX 78712,USA [2]Institut fur Kernphysik,Technische Universitat Darmstadt,Germany [3]The School of Physics and Astronomy,Tel-Aviv University,Tel-Aviv,69978,Israel

出　　处：《Matter and Radiation at Extremes》2017年第6期296-302,共7页极端条件下的物质与辐射（英文）

基　　金：This paper is based upon work supported by the Air Force Office of Scientific Research under award number FA9550-14-1-0045;The project was also supported by the NNSA coop-erative agreement DE-NA0002008;the Defense Advanced Research Projects Agency's PULSE program(12-63-PULSE-FP014).

摘　　要：Relativistic electron beams driven by laser wakefield acceleration were utilized to produce ultrashort neutron sources.The experiment was carried out on the 38 fs,~0.5 J,800 nm Ti:Sapphire laser in the 10 TW UT 3 laser lab at University of Texas at Austin.The target gas was a high density pulsed gas jet composed of 90%He and 10%N 2.The laser pulse with a peak intensity of 1.5×10^(18) W/cm^(2) interacted with the target to create a cylindrical plasma channel of 60 mm radius(FWHM)and 1.5 mm length(FWHM).Electron beams of~80 pC with the Gaussian energy distribution centered at 37 MeV and a width of 30 MeV(FWHM)were produced via laser wakefield acceleration.Neutron fluences of~2.4×10^(6) per shot with hundreds of ps temporal length were generated through bremsstrahlung and subsequent photoneutron reactions in a 26.6 mm thick tungsten converter.Results were compared with those of simulations using EPOCH and GEANT4,showing agreement in electron spectrum,neutron fluence,neutron angular distribution and conversion rate.

关 键 词：Neutron source LWFA Photoneutron reaction 

分 类 号：O57[理学—粒子物理与原子核物理]