Using multiple secondary fusion products to evaluate fuel <i>ρR</i>, electron temperature, and mix in deuterium-filled implosions at the NIF

Rinderknecht, H. G.; Rosenberg, Michael J.; Zylstra, A. B.; Lahmann, B.; Séguin, F.H.; Frenje, J. A.; Li, C. K.; Johnson, M. Gatu; Petrasso, R. D.; Hopkins, L. F. Berzak; Caggiano, J. A.; Divol, L.; Hartouni, E. P.; Hatarik, R.; Hatchett, S.; Pape, S. Le; Mackinnon, A. J.; McNaney, J. M.; Meezan, N. B.; Moran, M. J.; Bradley, P. A.; Kline, J. L.; Крашенинникова, Н. С.; Kyrala, G. A.; Murphy, T. J.; Schmitt, Mark J.; Tregillis, I. L.; Batha, S. H.; Knauer, J. P.; Kilkenny, J. D.

doi:10.1063/1.4928382

Cited by 24 publications

(11 citation statements)

References 49 publications

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“…Now the question is whether or not the secondary fusions produced by the energetic 3 H and 3 He can affect this energy value. The very recent studies point out that the total probability of these secondary fusions is generally on the order of 10 −2 or less [2] [26].…”

Section: Resultsmentioning

confidence: 99%

Achievement of Laser Fusion with High Energy Efficiency Using a Mixture of D and T Ions

Youssef¹,

Haparir²

2016

OJEE

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A mixture of deuterium (D) and tritium (T) is the most likely fuel for laser-driven inertial confinement fusion (ICF) reactors and hence DD and DT are the fusion reactions that will fire these reactors in the future. Neutrons produced from the two reactions will escape from the burning plasma, in the reactor core, and they are the only products possible to be measured directly. DT/DD neutron ratio is crucial for evaluation of T/D fuel ratio, burn control, tritium cycle and alpha particle self-heating power. To measure this ratio experimentally, the neutron spectra of DD and DT reactions have to be measured separately and simultaneously under high neutron counting with sufficient statistics (typically within 10% error) in a very short time and these issues are mutually contradicted. That is why it is not plausible to measure this high priority ratio for reactor performance accurately. Precise calculations of the DT/DD neutron ratio are needed. Here, we introduce such calculations using a three dimensional (3-D) Monte Carlo code at energies up to 40 MeV (the predicted maximum ion acceleration energy with the available laser systems). In addition, the fusion power ratio of DD and DT reactions is calculated for the same energy range. The study indicates that for a mixture of 50% deuterium and 50% triton, with taking into account the reactions D(d,n) 3 He and T(d,n) 4 He, the optimum energy value for achieving the most efficient laser-driven ICF is 0.08 MeV.

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Section: Resultsmentioning

confidence: 99%

Achievement of Laser Fusion with High Energy Efficiency Using a Mixture of D and T Ions

Youssef¹,

Haparir²

2016

OJEE

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“…[10][11][12] Next, we would like to extend the application of this detector to also measure particle yields. The fuel areal density (ρR) in deuterium gas filled ICF surrogate implosions can be inferred from the ratio of primary DD-n to secondary fusion products, both D 3 He-p and DT-n. 13 If the sensitivity of pTOF to protons Note: Contributed paper, published as part of the Proceedings of the 21st Topical Conference on High-Temperature Plasma Diagnostics, Madison, Wisconsin, USA, June 2016. and neutrons is determined, the detector could be used to diagnose fuel ρR. This would allow the measurement of shockbang time and fuel ρR using a single diagnostic and along a single line-of-sight.…”

Section: Background and Motivationmentioning

confidence: 99%

Sensitivity of chemical vapor deposition diamonds to DD and DT neutrons at OMEGA and the National Ignition Facility

Kabadi

Sio

Glebov

et al. 2016

Review of Scientific Instruments

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The particle-time-of-flight (pTOF) detector at the National Ignition Facility (NIF) is used routinely to measure nuclear bang-times in inertial confinement fusion implosions. The active detector medium in pTOF is a chemical vapor deposition diamond. Calibration of the detectors sensitivity to neutrons and protons would allow measurement of nuclear bang times and hot spot areal density (ρR) on a single diagnostic. This study utilizes data collected at both NIF and Omega in an attempt to determine pTOF's absolute sensitivity to neutrons. At Omega pTOF's sensitivity to DT-n is found to be stable to within 8% at different bias voltages. At the NIF pTOF's sensitivity to DD-n varies by up to 59%. This variability must be decreased substantially for pTOF to function as a neutron yield detector at the NIF. Some possible causes of this variability are ruled out.

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“…[20] The National Ignition Facility [21] (NIF) PDD experiments began with exploding-pusher capsules to generate a large amount of neutrons and protons for diagnostic calibration purpose. It was also used to develop the nuclear science platform [22,23] to probe the ion kinetic effects, [24,25] infer mixed mass, [26,27] and study the nuclear reaction relevant to stellar nucleosynthesis [28] and big-bang nucleosynthesis. [2] This article introduces our first PDD, DT fuel implosion experiments on the ShenGuang (SG) laser facility.…”

Section: Introductionmentioning

confidence: 99%

First polar direct-drive exploding-pusher target experiments on the ShenGuang laser facility*

Yang

Huang

et al. 2019

Chinese Phys. B

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Low density and low convergence implosion occurs in the exploding-pusher target experiment, and generates neutrons isotropically to develop a high yield platform. In order to validate the performance of ShenGuang (SG) laser facility and test nuclear diagnostics, all 48-beam lasers with an on-target energy of 48 kJ were firstly used to drive room-temperature, DT gas-filled glass targets. The optimization has been carried out and optimal drive uniformity was obtained by the combination of beam repointing and target. The final irradiation uniformity of less than 5% on polar direct-drive capsules of 540 μ m in diameter was achieved, and the highest thermonuclear yield of the polar direct-drive DT fuel implosion at the SG was 1.04×1013. The experiment results show neutron yields severely depend on the irradiation uniformity and laser timing, and decrease with the increase of the diameter and fuel pressure of the target. The thin CH ablator does not impact the implosion performance, but the laser drive uniformity is important. The simulated results validate that the cos γ distribution laser design is reasonable and can achieve a symmetric pressure distribution. Further optimization will focus on measuring the symmetry of the hot spot by self-emission imaging, increasing the diameter, and decreasing the fuel pressure.

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Using multiple secondary fusion products to evaluate fuel ρR, electron temperature, and mix in deuterium-filled implosions at the NIF

Cited by 24 publications

References 49 publications

Achievement of Laser Fusion with High Energy Efficiency Using a Mixture of D and T Ions

Achievement of Laser Fusion with High Energy Efficiency Using a Mixture of D and T Ions

Sensitivity of chemical vapor deposition diamonds to DD and DT neutrons at OMEGA and the National Ignition Facility

First polar direct-drive exploding-pusher target experiments on the ShenGuang laser facility*

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