1
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Wong CS, Strehlow J, Broughton DP, Luedtke SV, Huang CK, Bogale A, Fitzgarrald R, Nedbailo R, Schmidt JL, Schmidt TR, Twardowski J, Van Pelt A, Alvarez MA, Junghans A, Mix LT, Reinovsky RE, Rusby DR, Wang Z, Wolfe B, Albright BJ, Batha SH, Palaniyappan S. Robust unfolding of MeV x-ray spectra from filter stack spectrometer data. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2024; 95:023301. [PMID: 38341719 DOI: 10.1063/5.0190679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 01/17/2024] [Indexed: 02/13/2024]
Abstract
We present an inversion method capable of robustly unfolding MeV x-ray spectra from filter stack spectrometer (FSS) data without requiring an a priori specification of a spectral shape or arbitrary termination of the algorithm. Our inversion method is based upon the perturbative minimization (PM) algorithm, which has previously been shown to be capable of unfolding x-ray transmission data, albeit for a limited regime in which the x-ray mass attenuation coefficient of the filter material increases monotonically with x-ray energy. Our inversion method improves upon the PM algorithm through regular smoothing of the candidate spectrum and by adding stochasticity to the search. With these additions, the inversion method does not require a physics model for an initial guess, fitting, or user-selected termination of the search. Instead, the only assumption made by the inversion method is that the x-ray spectrum should be near a smooth curve. Testing with synthetic data shows that the inversion method can successfully recover the primary large-scale features of MeV x-ray spectra, including the number of x-rays in energy bins of several-MeV widths to within 10%. Fine-scale features, however, are more difficult to recover accurately. Examples of unfolding experimental FSS data obtained at the Texas Petawatt Laser Facility and the OMEGA EP laser facility are also presented.
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Affiliation(s)
- C-S Wong
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - J Strehlow
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - D P Broughton
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - S V Luedtke
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - C-K Huang
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - A Bogale
- Center for Energy Research, University of California - San Diego, La Jolla, California 92093, USA
| | - R Fitzgarrald
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - R Nedbailo
- Center for High Energy Density Science, University of Texas, Austin, Texas 78712, USA
| | - J L Schmidt
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - T R Schmidt
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - J Twardowski
- Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43210, USA
| | - A Van Pelt
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
- Center for High Energy Density Science, University of Texas, Austin, Texas 78712, USA
| | | | - A Junghans
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - L T Mix
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - R E Reinovsky
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - D R Rusby
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - Z Wang
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - B Wolfe
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - B J Albright
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - S H Batha
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - S Palaniyappan
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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2
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Temperature evolution of dense gold and diamond heated by energetic laser-driven aluminum ions. Sci Rep 2022; 12:15173. [PMID: 36071154 PMCID: PMC9452511 DOI: 10.1038/s41598-022-18758-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 08/18/2022] [Indexed: 11/24/2022] Open
Abstract
Recent studies have shown that energetic laser-driven ions with some energy spread can heat small solid-density samples uniformly. The balance among the energy losses of the ions with different kinetic energies results in uniform heating. Although heating with an energetic laser-driven ion beam is completed within a nanosecond and is often considered sufficiently fast, it is not instantaneous. Here we present a theoretical study of the temporal evolution of the temperature of solid-density gold and diamond samples heated by a quasimonoenergetic aluminum ion beam. We calculate the temporal evolution of the predicted temperatures of the samples using the available stopping power data and the SESAME equation-of-state tables. We find that the temperature distribution is initially very uniform, which becomes less uniform during the heating process. Then, the temperature uniformity gradually improves, and a good temperature uniformity is obtained toward the end of the heating process.
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3
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3D isotope density measurements by energy-resolved neutron imaging. Sci Rep 2022; 12:6648. [PMID: 35459915 PMCID: PMC9033771 DOI: 10.1038/s41598-022-10085-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 03/10/2022] [Indexed: 01/07/2023] Open
Abstract
Tools for three-dimensional elemental characterization are available on length scales ranging from individual atoms, using electrons as a probe, to micrometers with X-rays. However, for larger volumes up to millimeters or centimeters, quantitative measurements of elemental or isotope densities were hitherto only possible on the surface. Here, a novel quantitative elemental characterization method based on energy-resolved neutron imaging, utilizing the known neutron absorption cross sections with their 'finger-print' absorption resonance signatures, is demonstrated. Enabled by a pixilated time-of-flight neutron transmission detector installed at an intense short-pulsed spallation neutron source, for this demonstration 3.25 million state-of-the-art nuclear physics neutron transmission analyses were conducted to derive isotopic densities for five isotopes in 3D in a volume of 0.25 cm3. The tomographic reconstruction of the isotope densities provides elemental maps similar to X-ray microprobe maps for any cross section in the probed volume. The bulk isotopic density of a U-20Pu-10Zr-3Np-2Am nuclear transmutation fuel sample was measured, agrees well with mass-spectrometry and is evidence of the accuracy of the method.
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4
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Zimmer M, Scheuren S, Kleinschmidt A, Mitura N, Tebartz A, Schaumann G, Abel T, Ebert T, Hesse M, Zähter Ş, Vogel SC, Merle O, Ahlers RJ, Duarte Pinto S, Peschke M, Kröll T, Bagnoud V, Rödel C, Roth M. Demonstration of non-destructive and isotope-sensitive material analysis using a short-pulsed laser-driven epi-thermal neutron source. Nat Commun 2022; 13:1173. [PMID: 35246525 PMCID: PMC8897477 DOI: 10.1038/s41467-022-28756-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 02/01/2022] [Indexed: 11/09/2022] Open
Abstract
Neutrons are a valuable tool for non-destructive material investigation as their interaction cross sections with matter are isotope sensitive and can be used complementary to x-rays. So far, most neutron applications have been limited to large-scale facilities such as nuclear research reactors, spallation sources, and accelerator-driven neutron sources. Here we show the design and optimization of a laser-driven neutron source in the epi-thermal and thermal energy range, which is used for non-invasive material analysis. Neutron resonance spectroscopy, neutron radiography, and neutron resonance imaging with moderated neutrons are demonstrated for investigating samples in terms of isotope composition and thickness. The experimental results encourage applications in non-destructive and isotope-sensitive material analysis and pave the way for compact laser-driven neutron sources with high application potential.
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Affiliation(s)
- Marc Zimmer
- Technische Universität Darmstadt, Institut für Kernphysik, Darmstadt, 64289, Germany.
| | - Stefan Scheuren
- Technische Universität Darmstadt, Institut für Kernphysik, Darmstadt, 64289, Germany
| | - Annika Kleinschmidt
- GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, 64291, Germany.,Helmholtz Institut Jena, Jena, 07743, Germany
| | - Nikodem Mitura
- Technische Universität Darmstadt, Institut für Kernphysik, Darmstadt, 64289, Germany
| | - Alexandra Tebartz
- Technische Universität Darmstadt, Institut für Kernphysik, Darmstadt, 64289, Germany
| | - Gabriel Schaumann
- Technische Universität Darmstadt, Institut für Kernphysik, Darmstadt, 64289, Germany
| | - Torsten Abel
- Technische Universität Darmstadt, Institut für Kernphysik, Darmstadt, 64289, Germany
| | - Tina Ebert
- Technische Universität Darmstadt, Institut für Kernphysik, Darmstadt, 64289, Germany
| | - Markus Hesse
- Technische Universität Darmstadt, Institut für Kernphysik, Darmstadt, 64289, Germany
| | - Şêro Zähter
- GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, 64291, Germany
| | - Sven C Vogel
- Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | | | | | | | | | - Thorsten Kröll
- Technische Universität Darmstadt, Institut für Kernphysik, Darmstadt, 64289, Germany
| | - Vincent Bagnoud
- GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, 64291, Germany
| | - Christian Rödel
- Technische Universität Darmstadt, Institut für Kernphysik, Darmstadt, 64289, Germany
| | - Markus Roth
- Technische Universität Darmstadt, Institut für Kernphysik, Darmstadt, 64289, Germany
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5
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Monte Carlo Study of Imaging Plate Response to Laser-Driven Aluminum Ion Beams. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11020820] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
We measured the response of BAS-TR imaging plate (IP) to energetic aluminum ions up to 222 MeV, and compared it with predictions from a Monte Carlo simulation code using two different IP response models. Energetic aluminum ions were produced with an intense laser pulse, and the response was evaluated from cross-calibration between CR-39 track detector and IP energy spectrometer. For the first time, we obtained the response function of the BAS-TR IP for aluminum ions with a kinetic energy as high as 222 MeV. On close examination of the two IP response models, we confirm that the exponential model fits our experimental data better. Moreover, we find that the IP sensitivity in the exponential model is nearly constant in this energy range, suggesting that the response function can be determined even with little experimental data.
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6
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Manuel MJE, Tang H, Russell BK, Willingale L, Maksimchuk A, Green JS, Alfonso EL, Jaquez J, Carlson L, Neely D, Ma T. Enhanced spatial resolution of Eljen-204 plastic scintillators for use in rep-rated proton diagnostics. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:103301. [PMID: 33138566 DOI: 10.1063/5.0014949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 09/23/2020] [Indexed: 06/11/2023]
Abstract
A pixelated scintillator has been designed, fabricated, and tested using a laser-accelerated proton source for use in proton diagnostics at rep-rated laser facilities. The work presented here demonstrates the enhanced spatial resolution of thin, organic scintillators through a novel pixelation technique. Experimental measurements using laser-generated protons incident onto 130 μm-thick scintillators indicate a >20% reduction in the scintillator point spread function (PSF) for the detectors tested. The best performing pixelated detector reduced the ∼200 μm PSF of the stock material to ∼150 μm. The fabrication technique may be tailored to reduce the pixel size and achieve higher spatial resolutions.
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Affiliation(s)
- M J-E Manuel
- General Atomics, San Diego, California 92121, USA
| | - H Tang
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - B K Russell
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - L Willingale
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - A Maksimchuk
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - J S Green
- Central Laser Facility, STFC, Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX, United Kingdom
| | - E L Alfonso
- General Atomics, San Diego, California 92121, USA
| | - J Jaquez
- General Atomics, San Diego, California 92121, USA
| | - L Carlson
- General Atomics, San Diego, California 92121, USA
| | - D Neely
- Central Laser Facility, STFC, Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX, United Kingdom
| | - T Ma
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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7
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Gong Z, Mackenroth F, Wang T, Yan XQ, Toncian T, Arefiev AV. Direct laser acceleration of electrons assisted by strong laser-driven azimuthal plasma magnetic fields. Phys Rev E 2020; 102:013206. [PMID: 32795027 DOI: 10.1103/physreve.102.013206] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 06/09/2020] [Indexed: 06/11/2023]
Abstract
A high-intensity laser beam propagating through a dense plasma drives a strong current that robustly sustains a strong quasistatic azimuthal magnetic field. The laser field efficiently accelerates electrons in such a field that confines the transverse motion and deflects the electrons in the forward direction. Its advantage is a threshold rather than resonant behavior, accelerating electrons to high energies for sufficiently strong laser-driven currents. We study the electron dynamics via a test-electron model, specifically deriving the corresponding critical current density. We confirm the model's predictions by numerical simulations, indicating energy gains two orders of magnitude higher than achievable without the magnetic field.
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Affiliation(s)
- Z Gong
- SKLNPT, KLHEDP and CAPT, School of Physics, Peking University, Beijing 100871, China
- Center for High Energy Density Science, The University of Texas at Austin, Austin, Texas 78712, USA
| | - F Mackenroth
- Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California 92093, USA
| | - T Wang
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California 92093, USA
| | - X Q Yan
- SKLNPT, KLHEDP and CAPT, School of Physics, Peking University, Beijing 100871, China
| | - T Toncian
- Institute for Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf e.V., 01328 Dresden, Germany
| | - A V Arefiev
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California 92093, USA
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8
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Vogel SC, Fernandez JC, Gautier DC, Mitura N, Roth M, Schoenberg KF. Short-Pulse Laser-Driven Moderated Neutron Source. EPJ WEB OF CONFERENCES 2020. [DOI: 10.1051/epjconf/202023101008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Neutron production with laser-driven neutron sources was demonstrated. We outline the basics of laser-driven neutron sources, highlight some fundamental advantages, and quantitatively compare the neutron production at the TRIDENT laser sources with the well-established LANSCE pulsed neutron spallation source. Ongoing efforts by our team to continue development of these sources, in particular the LANSCE-ina-box instrument, are described. The promise of ultra-intense lasers as drivers for brilliant, compact, and highly efficient particle accelerators portends driving next-generation neutron sources, potentially replacing in some cases much larger conventional accelerators.
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9
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Gong Z, Mackenroth F, Yan XQ, Arefiev AV. Radiation reaction as an energy enhancement mechanism for laser-irradiated electrons in a strong plasma magnetic field. Sci Rep 2019; 9:17181. [PMID: 31748597 PMCID: PMC6868192 DOI: 10.1038/s41598-019-53644-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 11/04/2019] [Indexed: 11/15/2022] Open
Abstract
Conventionally, friction is understood as a mechanism depleting a physical system of energy and as an unavoidable feature of any realistic device involving moving parts. In this work, we demonstrate that this intuitive picture loses validity in nonlinear quantum electrodynamics, exemplified in a scenario where spatially random friction counter-intuitively results in a highly directional energy flow. This peculiar behavior is caused by radiation friction, i.e., the energy loss of an accelerated charge due to the emission of radiation. We demonstrate analytically and numerically how radiation friction can dramatically enhance the energy gain by electrons from a laser pulse in a strong magnetic field that naturally arises in dense laser-irradiated plasma. We find the directional energy boost to be due to the transverse electron momentum being reduced through friction whence the driving laser can accelerate the electron more efficiently. In the considered example, the energy of the laser-accelerated electrons is enhanced by orders of magnitude, which then leads to highly directional emission of gamma-rays induced by the plasma magnetic field.
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Affiliation(s)
- Z Gong
- SKLNPT, KLHEDP and CAPT, School of Physics, Peking University, Beijing, 100871, China.,Center for High Energy Density Science, The University of Texas at Austin, Austin, TX, 78712, USA
| | - F Mackenroth
- Max Planck Institute for the Physics of Complex Systems, 01187, Dresden, Germany.,Department of Mechanical and Aerospace Engineering, University of California at San Diego, La Jolla, CA, 92093, USA
| | - X Q Yan
- SKLNPT, KLHEDP and CAPT, School of Physics, Peking University, Beijing, 100871, China
| | - A V Arefiev
- Department of Mechanical and Aerospace Engineering, University of California at San Diego, La Jolla, CA, 92093, USA. .,Center for Energy Research, University of California at San Diego, La Jolla, CA, 92093, USA.
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10
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A physically cryptographic warhead verification system using neutron induced nuclear resonances. Nat Commun 2019; 10:4433. [PMID: 31570714 PMCID: PMC6769018 DOI: 10.1038/s41467-019-12386-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 09/06/2019] [Indexed: 11/09/2022] Open
Abstract
Arms control treaties are necessary to reduce the large stockpiles of the nuclear weapons that constitute one of the biggest dangers to the world. However, an impactful treaty hinges on effective inspection exercises to verify the participants’ compliance to the treaty terms. Such procedures would require verification of the authenticity of a warhead undergoing dismantlement. Previously proposed solutions lacked the combination of isotopic sensitivity and information security. Here we present the experimental feasibility proof of a technique that uses neutron induced nuclear resonances and is sensitive to the combination of isotopics and geometry. The information is physically encrypted to prevent the leakage of sensitive information. Our approach can significantly increase the trustworthiness of future arms control treaties while expanding their scope to include the verified dismantlement of nuclear warheads themselves. Inspection and authentication of warheads is important for nuclear safety and security. Here the authors report experimental scheme for the verification of nuclear warheads using the neutron resonance transmission analysis of a reference and candidate objects while preserving the sensitive information.
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11
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Fernández JC, Barnes CW, Mocko MJ, Zavorka L. Requirements and sensitivity analysis for temporally- and spatially-resolved thermometry using neutron resonance spectroscopy. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:094901. [PMID: 31575282 DOI: 10.1063/1.5031038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 08/21/2019] [Indexed: 06/10/2023]
Abstract
Neutron resonance spectroscopy (NRS) has been used extensively to make temperature measurements that are accurate, absolute, and nonperturbative within the interior of material samples under extreme conditions applied quasistatically. Yet NRS has seldom been used in dynamic experiments. There is a compelling incentive to do so because of the significant shortcomings of alternative techniques. An important barrier to adopting dynamic NRS thermometry is the difficulty in fielding it with conventional spallation neutron sources. To enable time-dependent and spatially resolved temperature measurements in dynamic environments, more compact neutron sources that can be used at user facilities in conjunction with other diagnostic probes (such as x-ray light sources) are required. Such sources may be available using ultrafast high-intensity optical lasers. We evaluate such possibilities by determining the sensitivities of the temperature estimate on neutron-beam and diagnostic parameters. Based on that evaluation, requirements are set on a pulsed neutron-source and diagnostics to make a meaningful dynamic temperature measurement. Dynamic thermometry measurements are examined in this context when driven by two alternative fast-neutron sources: the Los Alamos Neutron Scattering Center (LANSCE) proton accelerator driving isotropic spallation neutrons as a baseline and a laser-plasma ion accelerator driving a neutron beam from deuterium breakup. Strategies to close the gap between the required and demonstrated performance of laser-based fast-neutron sources are presented. A short-pulse high-intensity laser with state-of-the-art pulse contrast and an energy of a few hundred Joules would drive a compact neutron source suitable for NRS thermometry that could transform the dynamic study of materials.
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Affiliation(s)
- Juan C Fernández
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Cris W Barnes
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Michael J Mocko
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Lukas Zavorka
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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12
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Characterizing laser-plasma ion accelerators driving an intense neutron beam via nuclear signatures. Sci Rep 2019; 9:2004. [PMID: 30765811 PMCID: PMC6375962 DOI: 10.1038/s41598-019-39054-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 01/09/2019] [Indexed: 11/08/2022] Open
Abstract
Compact, bright neutron sources are opening up several emerging applications including detection of nuclear materials for national security applications. At Los Alamos National Laboratory, we have used a short-pulse laser to accelerate deuterons in the relativistic transparency regime. These deuterons impinge on a beryllium converter to generate neutrons. During the initial experiments where these neutrons were used for active interrogation of uranium and plutonium, we observed β-delayed neutron production from decay of 9Li, formed by the high-energy deuteron bombardment of the beryllium converter. Analysis of the delayed neutrons provides novel evidence of the divergence of the highest energy portion of the deuterons (i.e., above 10 MeV/nucleon) from the laser axis, a documented feature of the breakout afterburner laser-plasma ion acceleration mechanism. These delayed neutrons form the basis of non-intrusive diagnostics for determining the features of deuteron acceleration as well as monitoring neutron production for the next generation of laser-driven neutron sources.
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13
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Matsui R, Fukuda Y, Kishimoto Y. Quasimonoenergetic Proton Bunch Acceleration Driven by Hemispherically Converging Collisionless Shock in a Hydrogen Cluster Coupled with Relativistically Induced Transparency. PHYSICAL REVIEW LETTERS 2019; 122:014804. [PMID: 31012641 DOI: 10.1103/physrevlett.122.014804] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Indexed: 06/09/2023]
Abstract
An approach for accelerating a quasimonoenergetic proton bunch via a hemispherically converging collisionless shock created in laser-cluster interactions at the relativistically induced transparency (RIT) regime is studied using three-dimensional particle-in-cell simulations. By the action of focusing a petawatt class laser pulse onto a micron-size spherical hydrogen cluster, a crescent-shaped collisionless shock is launched at the laser-irradiated hemisphere and propagates inward. The shock converges at the sphere center in concurrence with the onset of the RIT, thereby allowing the proton bunch to be pushed out from the shock surface in the laser propagation direction. The proton bunch experiences further acceleration both inside and outside of the cluster to finally exhibit a quasimonoenergetic spectral peak around 300 MeV while maintaining a narrow energy spread (∼10%) and a small half-divergence angle (∼5°) via the effect of the RIT. This mechanism works for finite ranges of parameters with threshold values concerning the laser peak intensity and the cluster radius, resulting from the synchronization of the multiple processes in a self-consistent manner. The present scheme utilizing the internal and external degrees of freedom ascribed to the spherical cluster leads to the proton bunch alternative to the plain target, which allows the operation with a high repetition rate and impurity free.
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Affiliation(s)
- Ryutaro Matsui
- Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
- Kansai Photon Science Institute (KPSI), National Institutes for Quantum and Radiological Science and Technology (QST), 8-1-7 Umemidai, Kizugawa, Kyoto 619-0215, Japan
| | - Yuji Fukuda
- Kansai Photon Science Institute (KPSI), National Institutes for Quantum and Radiological Science and Technology (QST), 8-1-7 Umemidai, Kizugawa, Kyoto 619-0215, Japan
| | - Yasuaki Kishimoto
- Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
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14
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