摘要
The target backsheath field acceleration mechanism is one of the main mechanisms of laser-driven proton acceleration(LDPA)and strongly depends on the comprehensive performance of the ultrashort ultra-intense lasers used as the driving sources.The successful use of the SG-II Peta-watt(SG-II PW)laser facility for LDPA and its applications in radiographic diagnoses have been manifested by the good performance of the SG-II PW facility.Recently,the SG-II PW laser facility has undergone extensive maintenance and a comprehensive technical upgrade in terms of the seed source,laser contrast and terminal focus.LDPA experiments were performed using the maintained SG-II PW laser beam,and the highest cutoff energy of the proton beam was obviously increased.Accordingly,a double-film target structure was used,and the maximum cutoff energy of the proton beam was up to 70 MeV.These results demonstrate that the comprehensive performance of the SG-II PW laser facility was improved significantly.
基金
National Natural Science Foundation of China(Grant No.12075227)
the National Natural Science Foundation of China-NSAF(Grant No.U2130121)
the National Key Research and Development Program of China(Grant No.2016YFA0401102)
the Science Challenge Project(Grant No.TZ2018005).
