title: A uniformly redundant imaging array of penumbral apertures coupled with a heuristic reconstruction for hard x-ray and neutron imaging.
abstract: 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.
authors.affiliation: Institute of Laser Engineering, Osaka University, 2-6, Yamada-oka, Suita, Osaka, 565-0871, Japan.
authors.forename: Tatsuki
authors.initials: T
authors.lastname: Ueda
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Fujioka
authors.forename: Shinya
authors.initials: S
authors.lastname: Nozaki
authors.forename: Rumiko
authors.initials: R
authors.lastname: Azuma
authors.forename: Yen-Wei
authors.initials: YW
authors.lastname: Chen
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nishimura