Speaker
Hang Li
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P5.2021.pdf
Using laser-driven magnetized hohlraum to make a high temperature
symmetrical clean X-ray radiation source
Hang LI 1,2, Longyu KUANG 1,2, Longfei JING 1, Zhiwei LIN 1, Feng WANG 1, Shaoen JIANG 1,
Jian ZHENG 2, Ke LAN 3, Jie LIU 3, Yongkun DING 1,2,3 and B. Grant LOGAN 4
1
Research Center of Laser Fusion, China Academy of Engineering Physics, China
2
CAS Key Laboratory of Basic Plasma Physics and Department of Modern Physics,
University of Science and Technology of China, China
3
Institute of Applied Physics and Computational Mathematics, China
4
Lawrence Berkeley National Laboratory, USA
Strong magnetic fields in high power laser laboratories play a prominent role in high energy
density physics, while interaction of high power laser with high Z hohlraum is one effective way
of converting laser energy to high temperature X-ray radiation source. To obtain high temperature
symmetrical clean radiation source, capacitor-hohlraum target was designed based on
capacitor-coil target, so megagauss axial magnetic field can be generated in hohlraum by the
interaction of high power laser with the capacitor part. Then, interaction of laser with the
magnetized hohlraum can be studied. Firstly, compared with the traditional hohlraum, the strong
magnetic field in magnetized hohlraum can limit the plasma electron heat conduction in the laser
channels, increase the plasma temperature, and reduce scattering laser. Secondly, magnetic
pressure can suppress the hohlraum wall plasma motion, provide channels for laser injection, and
avoid plasma filling and large-scale laser-plasma interactions. Lastly, strong magnetic field can
guide hot electron out of hohlraum along the magnetic field lines, which provide clean hohlraum
radiation. These are of great significance in hohlraum energetics and laser interaction with
magnetized plasma.
500-700 T magnetic field was generated in a cylindrical hohlraum by the interaction of 1.8
kJ-1.0 ns-1064 nm laser with capacitor-coil target on SG-II laser facility, which was proven by
B-dot probe. Magnetic field suppressed plasma filling, forming a hollow region of the plasma
corona in the vacuum hohlraum, which was observed by an x-ray framing camera. Therefore,
strong magnetic field is proven to effectively suppress the plasma filling in vacuum hohlraum
instead of gas, providing an important potential way for hohlraum design in the laser
indirect-drive inertial confinement fusion.
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