A uniformly redundant imaging array of penumbral apertures coupled with a heuristic reconstruction for hard x-ray and neutron imaging.
A coded imaging and decoding (image reconstruction) scheme was developed for diagnosing a hot and dense region emitting hard x-rays and neutrons in laser-fusion plasmas. Because the imager was a uniformly redundant array of penumbral aperture (URPA) arranged in an M-matrix, URPA leads to N times (N: the total number of apertures) enhancement of signal intensity in comparison with a single penumbral aperture. A recorded penumbral image was reconstructed by a computer-based heuristic method to reduce artifacts caused by noises contained in a penumbral image. Applicability of this technique was investigated by imaging x-rays emitted from laser-produced plasmas, demonstrating a spatial resolution of 16 microm. Under the present conditions, the spatial resolution was determined dominantly by a detector resolution (10.5 microm) and a signal-to-noise ratio of the obtained penumbral image.
Ueda
Tatsuki
T
Institute of Laser Engineering, Osaka University, 2-6, Yamada-oka, Suita, Osaka, 565-0871, Japan.
Fujioka
Shinsuke
S
Nozaki
Shinya
S
Azuma
Rumiko
R
Chen
Yen-Wei
YW
Nishimura
Hiroaki
H