Coded imaging of thermonuclear neutrons (invited)

Nugent, Keith A.

doi:10.1063/1.1140125

Cited by 15 publications

(9 citation statements)

References 10 publications

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“…Before presenting our CMD reconstruction method, we will briefly introduce the general principle of penumbral imaging [4,8], and then focus on the CMD reconstruction method in Section 3.…”

Section: Principle Of Fast Neutron Penumbral Imaging and Experimentalmentioning

confidence: 99%

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A new reconstruction method based on classical molecular dynamics of neutron penumbral imaging in ICF

Dongjian¹,

Zhou²,

Tang³

et al. 2007

Nuclear Instruments and Methods in Physics Research Section A:

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“…Before presenting our CMD reconstruction method, we will briefly introduce the general principle of penumbral imaging [4,8], and then focus on the CMD reconstruction method in Section 3.…”

Section: Principle Of Fast Neutron Penumbral Imaging and Experimentalmentioning

confidence: 99%

“…At present, pinhole imaging and coded aperture imaging methods are widely used in diagnosis [4]. For pinhole imaging, a long hole, which is yet difficult to fabricate, is needed to ensure sufficient resolution.…”

Section: Introductionmentioning

confidence: 99%

A new reconstruction method based on classical molecular dynamics of neutron penumbral imaging in ICF

Dongjian¹,

Zhou²,

Tang³

et al. 2007

Nuclear Instruments and Methods in Physics Research Section A:

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“…It utilizes a "maximum entropy" technique to find an estimate for the source surface brightness that has the least possible structure consistent with the structure and the statistical errors of the penumbral image. 9 An initial guess for the source is used to stimulate penumbral image data, and the difference between the real and simulated penumbral images is used to find a more accurate source estimate; the process is repeated until convergence. This approach has been used in imaging with DD protons and DT ␣ particles.…”

Section: Introductionmentioning

confidence: 99%

D 3 He -proton emission imaging for inertial-confinement-fusion experiments (invited)

Séguin

Deciantis

Frenje

et al. 2004

Review of Scientific Instruments

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Proton emission imaging cameras, in combination with proton spectrometers and a proton temporal diagnostic, provide a great deal of information about the spatial structure and time evolution of inertial-confinement fusion capsule implosions. When used with D 3 He-filled capsules, multiple proton emission imaging cameras measure the spatial distribution of fusion burn, with three-dimensional information about burn symmetry. Simultaneously, multiple spectrometers measure areal density as a function of angle around the imploded capsule. Experiments at the OMEGA laser facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] have already proven the utility of this approach. An introduction to the hardware used for penumbral imaging, and algorithms used to create images of the burn region, are provided here along with simple scaling laws relating image resolution and signal-to-noise ratio to characteristics of the cameras and the burn region.

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“…The results on neutron penumbral imaging at the Nova laser fusion device in Livermore Laboratory (LLNL) was reported by Ress et al [2] The feasibility of 14 MeV fusion neutron imaging was proved. Subsequently Dsieder et al [5][6][7][8][9] also did some study on neutron penumbral imaging at OMEGA laser device in the United States. Chen et al [11,12] made a lot of researches on SG-II fusion facility using neutron penumbral imaging.…”

mentioning

confidence: 95%

“…A variety of methods were tried since 1970s and 1980s of the last century, a lot of experiences and results [1][2][3][4][5][6] accumulated in the last 40 years at the institutes in The United States, Japan, European countries [7][8][9][10] . Compared to the X-rays from the target capsule plasma, the fusion neutrons can bring out better information about spatial scale, shape, and uniformity of the implosion compression area of target pill.…”

mentioning

confidence: 99%

Penumbral imaging and numerical evaluation of large area source neutron imaging system

Zhang

et al. 2009

Sci. China Ser. E-Technol. Sci.

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The fusion neutron penumbral imaging system Monte Carlo model was established. The transfer functions of the two discrete units in the neutron source were obtained in two situations: Imaging in geometrical near-optical and real situation. The spatial resolutions of the imaging system in two situations were evaluated and compared. The penumbral images of four units in the source were obtained by means of 2-dimensional (2D) convolution and Monte Carlo simulation. The penumbral images were reconstructed with the same method of filter. The same results were confirmed. The encoding essence of penumbral imaging was revealed. With MCNP(Monte Carlo N-particle) simulation, the neutron penumbral images of the large area source (200 μm×200 μm) on scintillation fiber array were obtained. The improved Wiener filter method was used to reconstruct the penumbral image and the source image was obtained. The results agree with the preset neutron source image. The feasibility of the neutron imaging system was verified.penumbral imaging, reconstruction, unit source, spatial invariance, spatial resolution, MCNP codeIn inertial confinement fusion (ICF) experiment, through detecting the thermonuclear release, such as neutrons, protons and X-rays, a great deal of diagnostic information was obtained. A variety of methods were tried since 1970s and 1980s of the last century, a lot of experiences and results [1][2][3][4][5][6] accumulated in the last 40 years at the institutes in The United States, Japan, European countries [7][8][9][10] . Compared to the X-rays from the target capsule plasma, the fusion neutrons can bring out better information about spatial scale, shape, and uniformity of the implosion compression area of target pill. The detection efficiency is not high enough because the existing detector materials cross section to 14 MeV neutron between fast and ultra-fast neutrons is low. In order to obtain 14 MeV neutron image of thermonuclear fusion, reaction efficiency or neutron yield is improved in efforts, moreover, optimization design is also being made for the imaging aperture. As a result, the aperture diameter is larger than the fusion subject, and so pinhole imaging changes into penumbral imaging, which is the inheritance and development of pinhole image, and has the following advantages: Firstly, the neutron transports efficiency is much improved and appropriate for the diagnosis process at the low-yield neutrons; secondly, the detection limit of dynamic range can be reasonably as low as possible; thirdly, the penumbral image is larger than pinhole image, the resolution of source region can be upgraded moderately; lastly, the aperture is much larger than the fusion source, and so the mechanic requirements were reduced with respect to other encoding pinhole. The penumbral imaging geometric principle is shown in Figure 1. Penumbral image is a complex en-

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Coded imaging of thermonuclear neutrons (invited)

Cited by 15 publications

References 10 publications

A new reconstruction method based on classical molecular dynamics of neutron penumbral imaging in ICF

A new reconstruction method based on classical molecular dynamics of neutron penumbral imaging in ICF

D 3 He -proton emission imaging for inertial-confinement-fusion experiments (invited)

Penumbral imaging and numerical evaluation of large area source neutron imaging system

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