Background pressure effects on MeV protons accelerated via relativistically intense laser-plasma interactions
| Autor: | Joseph Snyder, William M. Roquemore, Chris Orban, Gregory Ngirmang, Kyle Frische, John C. Morrison, Scott Feister, Enam Chowdhury, Kevin George, Manh Le |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Multidisciplinary
Materials science Proton lcsh:R Ultra-high vacuum Energy conversion efficiency lcsh:Medicine Plasma Laser-produced plasmas Laser 01 natural sciences Article 010305 fluids & plasmas law.invention Ion law Torr 0103 physical sciences lcsh:Q Atomic physics lcsh:Science 010306 general physics Energy (signal processing) Plasma-based accelerators |
| Zdroj: | Scientific Reports Scientific Reports, Vol 10, Iss 1, Pp 1-7 (2020) |
| ISSN: | 2045-2322 |
| Popis: | We present how chamber background pressure affects energetic proton acceleration from an ultra-intense laser incident on a thin liquid target. A high-repetition-rate (100 Hz), 3.5 mJ laser with peak intensity of $$8 \times 10^{18}\,\text {Wcm}^{-2}$$ 8 × 10 18 Wcm - 2 impinged on a 450 nm sheet of flowing liquid ethylene glycol. For these parameters, we experimentally demonstrate a threshold in laser-to-proton conversion efficiency at background pressures $$< 8\,\text {Torr}$$ < 8 Torr , wherein the overall energy in ions $$>1\,\text {MeV}$$ > 1 MeV increases by an order of magnitude. Proton acceleration becomes increasingly efficient at lower background pressures and laser-to-proton conversion efficiency approaches a constant as the vacuum pressure decreases. We present two-dimensional particle-in-cell simulations and a charge neutralization model to support our experimental findings. Our experiment demonstrates that high vacuum is not required for energetic ion acceleration, which relaxes target debris requirements and facilitates applications of high-repetition rate laser-based proton accelerators. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|