Unfolding core asymmetries with x-ray emission images in symmetry diagnostic experiments.
A novel inversion technique is proposed to unfold core asymmetries at the source with x-ray emission images, which were obtained from imploded surrogate capsules in symmetry diagnostic experiments. The axisymmetrical core emission can be expanded as a Fourier series, with Legendre polynomials and spherical Bessel functions as bases concerned with polar angle and radius, respectively. A least-squares estimator is employed to obtain the unknown coefficients from its two-dimensional image data. The unfolded Legendre coefficients can be further used to test modeling of drive asymmetries in hohlraums. This technique is also demonstrated with a proof-of-principle experiment performed on the Shenguang II laser facility [L. Zunqi et al., Chin. J. Lasers B10, 6 (2001)].
National Key Laboratory of Laser Fusion, Research Center of Laser Fusion, CAEP, PO Box 919-986, Mianyang 621900, People's Republic of China.
T X
TX
Huang
Y K
YK
Ding
Z J
ZJ
Zheng
W Y
WY
Miao
Z R
ZR
Cao
S E
SE
Jiang
S Y
SY
Liu
Z L
ZL
Liu