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 lase...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.展开更多
We report the results of a comparative study of Fourier domain analysis(FDA)and texture analysis(TA)of optical coherence tomography(OCT)images of resected human breast tissues for binary classification between normal...We report the results of a comparative study of Fourier domain analysis(FDA)and texture analysis(TA)of optical coherence tomography(OCT)images of resected human breast tissues for binary classification between normalabnormal classes and benignmalignant classes.With the incorporation of Fisher linear discriminant analysis(FLDA)in TA for feature extraction,the TA-based algorithm provided improved diagnostic performance as compared to the FDAbased algorithm in discriminating OCT images corresponding to breast tissues with three different pathologies.The specificity and sensitivity values obtained for normalabnormal classification were both 100%,whereas they were 90% and 85%,respectively for benignmalignant classification.展开更多
基金This paper is based upon work supported by the Air Force Office of Scientific Research under award number FA9550-14-1-0045The project was also supported by the NNSA coop-erative agreement DE-NA0002008the Defense Advanced Research Projects Agency's PULSE program(12-63-PULSE-FP014).
文摘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.
文摘We report the results of a comparative study of Fourier domain analysis(FDA)and texture analysis(TA)of optical coherence tomography(OCT)images of resected human breast tissues for binary classification between normalabnormal classes and benignmalignant classes.With the incorporation of Fisher linear discriminant analysis(FLDA)in TA for feature extraction,the TA-based algorithm provided improved diagnostic performance as compared to the FDAbased algorithm in discriminating OCT images corresponding to breast tissues with three different pathologies.The specificity and sensitivity values obtained for normalabnormal classification were both 100%,whereas they were 90% and 85%,respectively for benignmalignant classification.
