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Bachmann B, MacLaren SA, Bhandarkar S, Briggs T, Casey D, Divol L, Döppner T, Fittinghoff D, Freeman M, Haan S, Hall GN, Hammel B, Hartouni E, Izumi N, Geppert-Kleinrath V, Khan S, Kozioziemski B, Krauland C, Landen O, Mariscal D, Marley E, Masse L, Meaney K, Mellos G, Moore A, Pak A, Patel P, Ratledge M, Rice N, Rubery M, Salmonson J, Sater J, Schlossberg D, Schneider M, Smalyuk VA, Trosseille C, Volegov P, Weber C, Williams GJ, Wray A. Measurement of Dark Ice-Ablator Mix in Inertial Confinement Fusion. Phys Rev Lett 2022; 129:275001. [PMID: 36638294 DOI: 10.1103/physrevlett.129.275001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 11/29/2022] [Indexed: 06/17/2023]
Abstract
We present measurements of ice-ablator mix at stagnation of inertially confined, cryogenically layered capsule implosions. An ice layer thickness scan with layers significantly thinner than used in ignition experiments enables us to investigate mix near the inner ablator interface. Our experiments reveal for the first time that the majority of atomically mixed ablator material is "dark" mix. It is seeded by the ice-ablator interface instability and located in the relatively cooler, denser region of the fuel assembly surrounding the fusion hot spot. The amount of dark mix is an important quantity as it is thought to affect both fusion fuel compression and burn propagation when it turns into hot mix as the burn wave propagates through the initially colder fuel region surrounding an igniting hot spot. We demonstrate a significant reduction in ice-ablator mix in the hot-spot boundary region when we increase the initial ice layer thickness.
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Affiliation(s)
- B Bachmann
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - S A MacLaren
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - S Bhandarkar
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - T Briggs
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - D Casey
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - L Divol
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - T Döppner
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - D Fittinghoff
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - M Freeman
- Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA
| | - S Haan
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - G N Hall
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - B Hammel
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - E Hartouni
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - N Izumi
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | | | - S Khan
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - B Kozioziemski
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - C Krauland
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - O Landen
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - D Mariscal
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - E Marley
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - L Masse
- Commissariat à l'Energie Atomique, DAM, DIF, F-91297 Arpajon, France
| | - K Meaney
- Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA
| | - G Mellos
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - A Moore
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - A Pak
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - P Patel
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - M Ratledge
- General Atomics, San Diego, California 92121, USA
| | - N Rice
- General Atomics, San Diego, California 92121, USA
| | - M Rubery
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - J Salmonson
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - J Sater
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - D Schlossberg
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - M Schneider
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - V A Smalyuk
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - C Trosseille
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - P Volegov
- Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA
| | - C Weber
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - G J Williams
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - A Wray
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
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Jeet J, Zylstra AB, Rekow V, Hardy CM, Pelepchan N, Eckart M, Kim Y, Rubery M, Moore AS, Schlossberg DJ, Folsom E. The Vacuum Cherenkov Detector (VCD) for γ-ray measurements in inertial confinement fusion experiments. Rev Sci Instrum 2022; 93:103543. [PMID: 36319345 DOI: 10.1063/5.0101830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 08/11/2022] [Indexed: 06/16/2023]
Abstract
Inertial confinement fusion experiments at both the National Ignition Facility (NIF) and the Laboratory for Laser Energetics OMEGA laser facility currently utilize Cherenkov detectors, with fused silica as the Cherenkov medium. At the NIF, the Quartz Cherenkov Detectors improve the precision of neutron time-of-flight measurements; and at OMEGA, the Diagnostic for Areal Density provides measurements of capsule shell areal densities. An inherent property of fused silica is the radiator's relatively low energy threshold for Cherenkov photon production (Ethreshold < 1 MeV), making it advantageous over gas-based Cherenkov detectors for experiments requiring low-energy γ detection. The Vacuum Cherenkov Detector (VCD) has been specifically designed for efficient detection of low energy γ's. Its primary use is in implosion experiments, which will study reactions relevant to stellar and big-bang nucleosynthesis, such as T(4He,γ)7Li, 4He(3He,γ)7Be, and 12C(p,γ)13N. The VCD is compatible with LLE's standard Ten-Inch Manipulator diagnostic insertion module. This work will outline the design and characterization of the VCD as well as provide results from recent experiments conducted at the OMEGA laser facility.
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Affiliation(s)
- J Jeet
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - A B Zylstra
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - V Rekow
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - C M Hardy
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - N Pelepchan
- Laboratory for Laser Energetics, Rochester, New York 14623, USA
| | - M Eckart
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Y Kim
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - M Rubery
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - A S Moore
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - D J Schlossberg
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - E Folsom
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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Jeet J, Eckart M, Gjemso J, Hahn K, Hartouni EP, Kerr S, Mariscal E, Moore AS, Rubery M, Schlossberg DJ. Proof-of-concept of a neutron time-of-flight ellipsoidal detector. Rev Sci Instrum 2021; 92:043555. [PMID: 34243390 DOI: 10.1063/5.0043829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 04/03/2021] [Indexed: 06/13/2023]
Abstract
The time-resolved measurement of neutrons emitted from nuclear implosions at inertial confinement fusion facilities is used to characterize the fusing plasma. Several significant quantities are routinely measured by neutron time-of-flight (nToF) detectors in these experiments. Current nToF detectors use scintillators as well as solid-state Cherenkov radiators. The latter has an inherently faster time response and can provide a co-registered γ-ray measurement as well as improved precision in the bulk hot-spot velocity. This work discusses a nToF ellipsoidal detector that also utilizes a solid-state Cherenkov radiator. The detector has the potential to achieve a fast instrument response function allowing for characterization of the γ-ray burn history as well as the ability to field the detector closer to the fusion source. Proof-of-concept testing of the nToF ellipsoidal detector has been conducted at the National Ignition Facility using commercial optics. A time-resolved neutron signal has been measured from the diagnostic. Preliminary simulations corroborate the results.
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Affiliation(s)
- J Jeet
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - M Eckart
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - J Gjemso
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - K Hahn
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - E P Hartouni
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - S Kerr
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - E Mariscal
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - A S Moore
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - M Rubery
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - D J Schlossberg
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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Zylstra AB, Herrmann HW, Kim YH, McEvoy A, Meaney K, Glebov VY, Forrest C, Rubery M. Improved calibration of the OMEGA gas Cherenkov detector. Rev Sci Instrum 2019; 90:123504. [PMID: 31893806 DOI: 10.1063/1.5128765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Accepted: 11/24/2019] [Indexed: 06/10/2023]
Abstract
Inertial fusion implosions are diagnosed using γ rays to characterize the implosion physics or measure basic nuclear properties, including cross sections. For the latter, previously reported measurements at laser facilities using gas Cherenkov detectors are limited by a large systematic uncertainty in the detector response. We present a novel in situ calibration technique using neutron inelastic scattering, which we apply to the new GCD-3 detector. The calibration accuracy is improved by ∼3× over the previous method.
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Affiliation(s)
- A B Zylstra
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - H W Herrmann
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Y H Kim
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - A McEvoy
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - K Meaney
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - V Yu Glebov
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - C Forrest
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - M Rubery
- Plasma Physics Department, AWE plc, Reading RG7 4PR, United Kingdom
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Hartouni EP, Beeman B, Eckart MJ, Grim GP, Hatarik R, Moore AS, Rubery M, Sayre D, Schlossberg DJ, Waltz C. Uncertainty analysis of response functions and γ -backgrounds on T ion and t 0 measurements from Cherenkov neutron detectors at the National Ignition Facility (NIF). Rev Sci Instrum 2018; 89:10I140. [PMID: 30399962 DOI: 10.1063/1.5038816] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Accepted: 07/10/2018] [Indexed: 06/08/2023]
Abstract
Cherenkov radiators deployed to measure the neutron time-of-flight spectrum have response times associated with the neutron transit across the detector and are free from long time response tails characteristic of scintillation detectors. The Cherenkov radiation results from simple physical processes which makes them amenable to high fidelity Monte Carlo simulation. The instrument response function of neutron time-of-flight systems is a major contributor to both the systematic and statistical uncertainties of the parameters used to describe these spectra; in particular, the first and second moments of these distributions are associated with arrival time, t0, and ion temperature, Tion. We present the results of uncertainty analysis showing the significant reduction of the uncertainty in determining these quantities in the Cherenkov detector system recently deployed at NIF. The increased sensitivity to gamma radiation requires additional consideration of the effect of this background to the uncertainties in both t0 and Tion.
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Affiliation(s)
- E P Hartouni
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - B Beeman
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - M J Eckart
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - G P Grim
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - R Hatarik
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - A S Moore
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - M Rubery
- Atomic Weapons Establishment, Aldermaston, Reading RG7 4PR, United Kingdom
| | - D Sayre
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - D J Schlossberg
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - C Waltz
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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Zylstra AB, Herrmann HW, Johnson MG, Kim YH, Frenje JA, Hale G, Li CK, Rubery M, Paris M, Bacher A, Brune CR, Forrest C, Glebov VY, Janezic R, McNabb D, Nikroo A, Pino J, Sangster TC, Séguin FH, Seka W, Sio H, Stoeckl C, Petrasso RD. Using Inertial Fusion Implosions to Measure the T+^{3}He Fusion Cross Section at Nucleosynthesis-Relevant Energies. Phys Rev Lett 2016; 117:035002. [PMID: 27472118 DOI: 10.1103/physrevlett.117.035002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Indexed: 06/06/2023]
Abstract
Light nuclei were created during big-bang nucleosynthesis (BBN). Standard BBN theory, using rates inferred from accelerator-beam data, cannot explain high levels of ^{6}Li in low-metallicity stars. Using high-energy-density plasmas we measure the T(^{3}He,γ)^{6}Li reaction rate, a candidate for anomalously high ^{6}Li production; we find that the rate is too low to explain the observations, and different than values used in common BBN models. This is the first data directly relevant to BBN, and also the first use of laboratory plasmas, at comparable conditions to astrophysical systems, to address a problem in nuclear astrophysics.
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Affiliation(s)
- A B Zylstra
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - H W Herrmann
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - M Gatu Johnson
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Y H Kim
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - J A Frenje
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - G Hale
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - C K Li
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - M Rubery
- Plasma Physics Department, AWE plc, Reading RG7 4PR, United Kingdom
| | - M Paris
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - A Bacher
- Indiana University, Bloomington, Indiana 47405, USA
| | - C R Brune
- Ohio University, Athens, Ohio 45701, USA
| | - C Forrest
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - V Yu Glebov
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - R Janezic
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - D McNabb
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - A Nikroo
- General Atomics, San Diego, California 92186, USA
| | - J Pino
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - T C Sangster
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - F H Séguin
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - W Seka
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - H Sio
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - C Stoeckl
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - R D Petrasso
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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Herrmann HW, Hoffman N, Wilson DC, Stoeffl W, Dauffy L, Kim YH, McEvoy A, Young CS, Mack JM, Horsfield CJ, Rubery M, Miller EK, Ali ZA. Diagnosing inertial confinement fusion gamma ray physics (invited). Rev Sci Instrum 2010; 81:10D333. [PMID: 21033853 DOI: 10.1063/1.3495770] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The gamma reaction history (GRH) diagnostic is a multichannel, time-resolved, energy-thresholded γ-ray spectrometer that provides a high-bandwidth, direct-measurement of fusion reaction history in inertial confinement fusion implosion experiments. 16.75 MeV deuterium+tritium (DT) fusion γ-rays, with a branching ratio of the order of 10(-5)γ/(14 MeV n), are detected to determine fundamental burn parameters, such as nuclear bang time and burn width, critical to achieving ignition at the National Ignition Facility. During the tritium/hydrogen/deuterium ignition tuning campaign, an additional γ-ray line at 19.8 MeV, produced by hydrogen+tritium fusion with a branching ratio of unity, will increase the available γ-ray signal and may allow measurement of reacting fuel composition or ion temperature. Ablator areal density measurements with the GRH are also made possible by detection of 4.43 MeV γ-rays produced by inelastic scatter of DT fusion neutrons on (12)C nuclei in the ablating plastic capsule material.
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Affiliation(s)
- H W Herrmann
- Los Alamos National Laboratory, P.O. Box 1663, M/S E526, Los Alamos, New Mexico 87545, USA.
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McEvoy AM, Herrmann HW, Horsfield CJ, Young CS, Miller EK, Mack JM, Kim Y, Stoeffl W, Rubery M, Evans S, Sedillo T, Ali ZA. Gamma bang time analysis at OMEGA. Rev Sci Instrum 2010; 81:10D322. [PMID: 21033846 DOI: 10.1063/1.3485083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Absolute bang time measurements with the gas Cherenkov detector (GCD) and gamma reaction history (GRH) diagnostic have been performed to high precision at the OMEGA laser facility at the University of Rochester with bang time values for the two diagnostics agreeing to within 5 ps on average. X-ray timing measurements of laser-target coupling were used to calibrate a facility-generated laser timing fiducial with rms spreads in the measured coupling times of 9 ps for both GCD and GRH. Increased fusion yields at the National Ignition Facility (NIF) will allow for improved measurement precision with the GRH easily exceeding NIF system design requirements.
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Affiliation(s)
- A M McEvoy
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
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Herrmann HW, Young CS, Mack JM, Kim YH, McEvoy A, Evans S, Sedillo T, Batha S, Schmitt M, Wilson DC, Langenbrunner JR, Malone R, Kaufman MI, Cox BC, Frogget B, Miller EK, Ali ZA, Tunnell TW, Stoeffl W, Horsfield CJ, Rubery M. ICF gamma-ray reaction history diagnostics. ACTA ACUST UNITED AC 2010. [DOI: 10.1088/1742-6596/244/3/032047] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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