scholarly journals Measuring x-ray burn history with the Streaked Polar Instrumentation for Diagnosing Energetic Radiation (SPIDER) at the National Ignition Facility (NIF)

2012 ◽  
Author(s):  
S. F. Khan ◽  
P. M. Bell ◽  
D. K. Bradley ◽  
S. R. Burns ◽  
J. R. Celeste ◽  
...  
Keyword(s):  
National Ignition Facility ◽  
X Ray ◽  
Energetic Radiation

scholarly journals Investigation of high X-ray conversion efficiency Kr filled gas sources at the National Ignition Facility

2019 ◽  
Vol 26 (6) ◽  
pp. 063105 ◽  
Author(s):  
M. J. May ◽  
G. E. Kemp ◽  
J. D. Colvin ◽  
D. A. Liedahl ◽  
P. L. Poole ◽  
...  
Keyword(s):  
Conversion Efficiency ◽  
National Ignition Facility ◽  
X Ray

scholarly journals Multi-keV x-ray source development experiments on the National Ignition Facility

2010 ◽  
Vol 17 (8) ◽  
pp. 082701 ◽  
Author(s):  
K. B. Fournier ◽  
M. J. May ◽  
J. D. Colvin ◽  
J. O. Kane ◽  
M. Schneider ◽  
...  
Keyword(s):  
National Ignition Facility ◽  
X Ray

scholarly journals Capsule design for the National Ignition Facility

1999 ◽  
Vol 17 (2) ◽  
pp. 217-224 ◽  
Author(s):  
T.R. DITTRICH ◽  
S.W. HAAN ◽  
M.M. MARINAK ◽  
D.E. HINKEL ◽  
S.M. POLLAINE ◽  
...  
Keyword(s):  
Dopant Concentration ◽  
Three Dimensions ◽  
Initial Surface ◽  
National Ignition Facility ◽  
X Ray ◽  
Ongoing Effort ◽  
Surface Finishes ◽  
Material Homogeneity ◽  
Indirect Drive ◽  
Reduced Scale

Several choices exist in the design and production of capsules intended to ignite and propagate fusion burn of the deuterium–tritium (D–T) fuel when imploded by indirect drive at the National Ignition Facility (NIF). These choices include ablator material, ablator dopant concentration and distribution, capsule dimensions, and X-ray drive profile (shock timings and strengths). The choice of ablator material must also include fabrication and material characteristics, such as attainable surface finishes, permeability, strength, transparency to radio frequency and infrared radiation, thermal conductivity, and material homogeneity. Understanding the advantages and/or limitations of these choices is an ongoing effort for LLNL and LANL designers. At this time, simulations in one-, two-, and three-dimensions show that capsules with either a copper-doped beryllium or a polyimide (C22H10N2O4) ablator material have both the least sensitivity to initial surface roughnesses and favorable fabrication qualities. Simulations also indicate the existence of capsule designs based on these ablator materials which ignite and burn when imploded by less than nominal laser performance (900-kJ energy, 250-TW power, producing 250-eV peak radiation temperature). We will describe and compare these reduced-scale capsules, in addition to several designs which use the expected 300-eV peak X-ray drive obtained from operating the NIF laser at 1.3 MJ and 500 TW.

scholarly journals Bremsstrahlung x-ray generation for high optical depth radiography applications on the National Ignition Facility

2018 ◽  
Vol 89 (10) ◽  
pp. 10G121 ◽  
Author(s):  
C. M. Huntington ◽  
J. M. McNaney ◽  
E. Gumbrell ◽  
A. Krygier ◽  
C. Wehrenberg ◽  
...  
Keyword(s):  
Optical Depth ◽  
National Ignition Facility ◽  
X Ray

scholarly journals Combined neutron and x-ray imaging at the National Ignition Facility (invited)

2016 ◽  
Vol 87 (11) ◽  
pp. 11D703 ◽  
Author(s):  
C. R. Danly ◽  
K. Christensen ◽  
V. E. Fatherley ◽  
D. N. Fittinghoff ◽  
G. P. Grim ◽  
...  
Keyword(s):  
National Ignition Facility ◽  
X Ray ◽  
X Ray Imaging

scholarly journals Radiation-hydrodynamical models of X-ray photoevaporation in carbon-depleted circumstellar discs

2019 ◽  
Vol 490 (4) ◽  
pp. 5596-5614 ◽  
Author(s):  
Lisa Wölfer ◽  
Giovanni Picogna ◽  
Barbara Ercolano ◽  
Ewine F van Dishoeck
Keyword(s):  
Mass Loss ◽  
Gas Phase ◽  
Central Star ◽  
X Rays ◽  
Hydrodynamical Models ◽  
X Ray ◽  
Energetic Radiation ◽  
Low Metallicity ◽  
Penetration Depths ◽  
Loss Rates

ABSTRACT The so-called transition discs provide an important tool to probe various mechanisms that might influence the evolution of protoplanetary discs and therefore the formation of planetary systems. One of these mechanisms is photoevaporation due to energetic radiation from the central star, which can in principal explain the occurrence of discs with inner cavities like transition discs. Current models, however, fail to reproduce a subset of the observed transition discs, namely objects with large measured cavities and vigorous accretion. For these objects the presence of (multiple) giant planets is often invoked to explain the observations. In our work, we explore the possibility of X-ray photoevaporation operating in discs with different gas-phase depletion of carbon and show that the influence of photoevaporation can be extended in such low-metallicity discs. As carbon is one of the main contributors to the X-ray opacity, its depletion leads to larger penetration depths of X-rays in the disc and results in higher gas temperatures and stronger photoevaporative winds. We present radiation-hydrodynamical models of discs irradiated by internal X-ray + EUV radiation assuming carbon gas-phase depletions by factors of three, 10, and 100 and derive realistic mass-loss rates and profiles. Our analysis yields robust temperature prescriptions as well as photoevaporative mass-loss rates and profiles which may be able to explain a larger fraction of the observed diversity of transition discs.

scholarly journals Absolute calibration of the continuum x-ray spectrometer (ConSpec) at the National Ignition Facility

2019 ◽  
Vol 14 (12) ◽  
pp. P12009-P12009 ◽  
Author(s):  
M.J. MacDonald ◽  
B. Kozioziemski ◽  
A.G. MacPhee ◽  
M.B. Schneider ◽  
J. Ayers ◽  
...  
Keyword(s):  
Absolute Calibration ◽  
National Ignition Facility ◽  
X Ray ◽  
The Continuum

scholarly journals X-ray driven implosions at ignition relevant velocities on the National Ignition Facility

2013 ◽  
Vol 20 (5) ◽  
pp. 056311 ◽  
Author(s):  
N. B. Meezan ◽  
A. J. MacKinnon ◽  
D. G. Hicks ◽  
E. L. Dewald ◽  
R. Tommasini ◽  
...  
Keyword(s):  
National Ignition Facility ◽  
X Ray
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