CaltechAUTHORS
Published March 1, 2021 | Version Published
Journal Article Open

Enhancing positron production using front surface target structures

Creators

  • 1. ROR icon Lawrence Livermore National Laboratory
  • 2. ROR icon University of Rochester
  • 3. ROR icon General Atomics (United States)
  • 4. ROR icon California Institute of Technology
  • 5. ROR icon University of California, San Diego

Abstract

We report a target design which produced a substantial gain in relativistic electron-positron pair production using high-intensity lasers and targets with large-scale micro-structures on their surface. Comparing to an unstructured target, a selected Si microwire array target yielded a near 100% increase in the laser-to-positron conversion efficiency and produced a 10 MeV increase in the average emitted positron energy under nominally the same experimental conditions. We had established a multi-scale particle-in-cell simulation scheme to simulate both the laser absorption and the subsequent pair productions in a thick metal target. The experimental results are supported by the simulations demonstrating the performance increase is due to a higher conversion efficiency of laser energy into electrons with kinetic energies greater than 10 MeV due to enhanced direct laser acceleration of electrons enabled by the microwire array.

Additional Information

© 2021 Published under license by AIP Publishing. Submitted: 19 November 2020; Accepted: 8 February 2021; Published Online: 2 March 2021. We thank the OMEGA EP team for laser operation and technical support. This work was performed under the auspices of the U.S. DOE by LLNL under Contract No. DEAC5207NA27344, and funded by LDRD (No. 17ERD010). The fabrication of Si microwire arrays was supported through the Office of Science of the U.S. Department of Energy under Award No. DE- SC0004993. Additional support for this work was provided by the Lockheed Martin Corporation (Award No. 4103810021). We thank the staff at the Kavli Nanoscience Institute at Caltech for their technical assistance with fabrication. Data Availability: The data that support the findings of this study are available from the corresponding author upon reasonable request.

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Published - 094101_1_online.pdf

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Additional details

Identifiers

Eprint ID
108282
Resolver ID
CaltechAUTHORS:20210303-071742285

Funding

Department of Energy (DOE)
DE-AC52-07NA27344
Los Alamos National Laboratory
17ERD010
Department of Energy (DOE)
DE-SC0004993
Lockheed Martin
4103810021

Dates

Created
2021-03-03
Created from EPrint's datestamp field
Updated
2023-10-02
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Kavli Nanoscience Institute