Optimizing MeV photon dose generation in laser-solid interactions via stable beam propagation
Bremsstrahlung MeV x rays with high doses are essential for radiography of dense objects. Intense, short-pulse laser-driven MeV x-ray sources offer a promising solution, but understanding how the dose scales with laser intensity is crucial for their development. While theory predicts a square root scaling with laser intensity, experimental verification has been hindered by significant shot-to-shot variations, often exacerbated by long preplasma scale lengths from low laser contrast. Here, we demonstrate low shot-to-shot dose variation and confirm the theoretical scaling using high-contrast OMEGA EP laser interactions with millimeter-thick tantalum foils, achieving MeV x-ray doses up to 5.4 rad at 1 m for <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:msub><a:mi>E</a:mi><a:mi>photon</a:mi></a:msub><a:mspace width="4pt"/><a:mo>></a:mo></a:mrow></a:math> 500 keV. Simulations reveal that the unique focal spot of the OMEGA EP laser enables efficient x-ray generation and reduced variability by facilitating deeper laser penetration into dense plasma, even with shorter preplasma scale lengths.
Authors
- A. Van Pelt (ORCID: https://orcid.org/0009-0009-0843-9943)
- D. C. Gautier (ORCID: https://orcid.org/0000-0001-7778-311X)
- D. J. Stark (ORCID: https://orcid.org/0000-0002-0364-2733)
- J. Strehlow (ORCID: https://orcid.org/0000-0001-5576-0945)
- J. C. Fernández (ORCID: https://orcid.org/0000-0002-1438-1815)
- J Twardowski (ORCID: https://orcid.org/0000-0002-0246-6782)
- A. Bogale (ORCID: https://orcid.org/0000-0003-0601-1512)
- Scott V. Luedtke (ORCID: https://orcid.org/0000-0003-1670-2835)
- S. Palaniyappan (ORCID: https://orcid.org/0000-0001-6377-1206)
- Lin Yin (ORCID: https://orcid.org/0000-0002-8978-5320)
- L. Tyler Mix (ORCID: https://orcid.org/0000-0002-8136-3457)
- Chun-Shang Wong (ORCID: https://orcid.org/0000-0002-2698-7208)
- B. J. Albright (ORCID: https://orcid.org/0000-0002-7789-6525)
- Rebecca Fitzgarrald (ORCID: https://orcid.org/0000-0003-1633-8113)
- F. N. Beg (ORCID: https://orcid.org/0000-0003-0391-8944)
Institutions
- Los Alamos National Laboratory (US)
- University of Michigan (US)
- University of California San Diego (US)
- The Ohio State University (US)
Publication Details
- Journal
- Physical Review Research
- Published
- 2025-05-19
- DOI
- https://doi.org/10.1103/physrevresearch.7.023169
- Citations
- 5
- Primary Topic
- Laser-Plasma Interactions and Diagnostics
- Type
- article
- Field-Weighted Citation Impact
- 3.74
Funders
- U.S. Department of Energy
- University of Rochester
- National Nuclear Security Administration
- Office of the President, University of California
- Laboratory Directed Research and Development
- Los Alamos National Laboratory