title: Measurements of X-ray doses and spectra produced by picosecond laser-irradiated solid targets.
abstract: Experiments have shown that high-intensity laser interaction with a solid target can generate significant X-ray doses. This study was conducted to determine the X-ray doses and spectra produced for picosecond laser-irradiated solid targets. The photon doses and X-ray spectra in the laser forward and side directions were measured using an XG III ps 300 TW laser system. For laser intensities of 7×1018-4×1019W/cm2, the maximum photon dose was 16.8 mSv at 50cm with a laser energy of ~153J on a 1-mm Ta target. The photon dose in the forward direction increased more significantly with increasing laser intensity than that in the side direction. For photon energies >300keV, the X-ray spectrum can be fit with an effective temperature distribution of the exponential form, dN/dE = k× exp(-E/Tx). The X-ray temperature Txincreased with the laser intensity in the forward direction with values of 0.46-0.75MeV. Txwas less strongly correlated with the laser intensity in the side direction with values of 0.29-0.32MeV. The escaping electron spectrum was also measured. The measured electron temperature was correlated with the electron temperature predicted by the ponderomotive law. The observations in this experiment were also investigated numerically. A good agreement was observed between the experimental and simulation results.
authors.affiliation: Department of Engineering Physics, Tsinghua University, Beijing 100084, China; Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Yang
authors.affiliation: Department of Engineering Physics, Tsinghua University, Beijing 100084, China; Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing, China. Electronic address: qiurui@tsinghua.edu.cn.
authors.forename: Rui
authors.initials: R
authors.lastname: Qiu
authors.affiliation: Science and Technology on Plasma Physics Laboratory, Laser Fusion Research Center, China Academy of Engineering Physics, Mianyang 621900, China.
authors.forename: Minghai
authors.initials: M
authors.lastname: Yu
authors.affiliation: Science and Technology on Plasma Physics Laboratory, Laser Fusion Research Center, China Academy of Engineering Physics, Mianyang 621900, China.
authors.forename: Jinlong
authors.initials: J
authors.lastname: Jiao
authors.affiliation: Department of Engineering Physics, Tsinghua University, Beijing 100084, China; Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing, China; Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Lu
authors.affiliation: Science and Technology on Plasma Physics Laboratory, Laser Fusion Research Center, China Academy of Engineering Physics, Mianyang 621900, China.
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Yan
authors.affiliation: Science and Technology on Plasma Physics Laboratory, Laser Fusion Research Center, China Academy of Engineering Physics, Mianyang 621900, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Science and Technology on Plasma Physics Laboratory, Laser Fusion Research Center, China Academy of Engineering Physics, Mianyang 621900, China.
authors.forename: Zhimeng
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Science and Technology on Plasma Physics Laboratory, Laser Fusion Research Center, China Academy of Engineering Physics, Mianyang 621900, China; IFSA, Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Weimin
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Department of Engineering Physics, Tsinghua University, Beijing 100084, China; Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing, China.
authors.forename: Junli
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Engineering Physics, Tsinghua University, Beijing 100084, China; Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
keywords: Dosimetry; Hard X-ray; Picosecond laser; X-ray spectrometry