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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. Rev Sci Instrum 2024; 95:023301. [PMID: 38341719 DOI: 10.1063/5.0190679] [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: 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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von der Leyen MW, Holloway J, Ma Y, Campbell PT, Aboushelbaya R, Qian Q, Antoine AF, Balcazar M, Cardarelli J, Feng Q, Fitzgarrald R, Hou BX, Kalinchenko G, Latham J, Maksimchuk AM, McKelvey A, Nees J, Ouatu I, Paddock RW, Spiers B, Thomas AGR, Timmis R, Krushelnick K, Norreys PA. Observation of Monoenergetic Electrons from Two-Pulse Ionization Injection in Quasilinear Laser Wakefields. Phys Rev Lett 2023; 130:105002. [PMID: 36962018 DOI: 10.1103/physrevlett.130.105002] [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: 11/09/2021] [Revised: 01/31/2023] [Accepted: 02/09/2023] [Indexed: 06/18/2023]
Abstract
The generation of low emittance electron beams from laser-driven wakefields is crucial for the development of compact x-ray sources. Here, we show new results for the injection and acceleration of quasimonoenergetic electron beams in low amplitude wakefields experimentally and using simulations. This is achieved by using two laser pulses decoupling the wakefield generation from the electron trapping via ionization injection. The injection duration, which affects the beam charge and energy spread, is found to be tunable by adjusting the relative pulse delay. By changing the polarization of the injector pulse, reducing the ionization volume, the electron spectra of the accelerated electron bunches are improved.
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Affiliation(s)
- M W von der Leyen
- Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom
- John Adams Institute for Accelerator Science, Denys Wilkinson Building, Oxford OX1 3RH, United Kingdom
| | - J Holloway
- Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom
| | - Y Ma
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - P T Campbell
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - R Aboushelbaya
- Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom
| | - Q Qian
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - A F Antoine
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - M Balcazar
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - J Cardarelli
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Q Feng
- Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom
| | - R Fitzgarrald
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - B X Hou
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - G Kalinchenko
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - J Latham
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - A M Maksimchuk
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - A McKelvey
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - J Nees
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - I Ouatu
- Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom
| | - R W Paddock
- Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom
| | - B Spiers
- Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom
| | - A G R Thomas
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - R Timmis
- Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom
| | - K Krushelnick
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - P A Norreys
- Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom
- John Adams Institute for Accelerator Science, Denys Wilkinson Building, Oxford OX1 3RH, United Kingdom
- Central Laser Facility, STFC, Rutherford Appleton Laboratory, Didcot, OX11 0QX, United Kingdom
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