Disorder-induced heating as a mechanism for fast neutral gas heating in atmospheric pressure plasmas

Journal Article · 07 February 2024 · Plasma Sources Science and Technology

DOI: https://doi.org/10.1088/1361-6595/ad257e · OSTI ID:2293604

Acciarri, M. D. ; Moore, C. ; Baalrud, S. D.

Abstract Recent findings suggest that ions are strongly correlated in atmospheric pressure plasmas if the ionization fraction is sufficiently high ( $\gtrsim {10}^{-5}$ ). A consequence is that ionization causes disorder-induced heating (DIH), which triggers a significant rise in ion temperature on a picosecond timescale. This is followed by a rise in the neutral gas temperature on a longer timescale of up to nanoseconds due to ion–neutral temperature relaxation. The sequence of DIH and ion–neutral temperature relaxation suggests a new mechanism for ultrafast neutral gas heating. Previous work considered only the case of an instantaneous ionization pulse, whereas the ionization pulse extends over nanoseconds in many experiments. Here, molecular dynamics simulations are used to analyze the evolution of ion and neutral gas temperatures for a gradual ionization over several nanoseconds. The results are compared with published experimental results from a nanosecond pulsed discharge, showing good agreement with a measurement of fast neutral gas heating.

• Research Organization: Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Univ. of Michigan, Ann Arbor, MI (United States)
• Sponsoring Organization: USDOE; USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Fusion Energy Sciences (FES)
• Grant/Contract Number: NA0003525; SC0022201
• OSTI ID: 2293604
• Report Number(s): SAND-2024-01480J
• Journal Information: Plasma Sources Science and Technology, Journal Name: Plasma Sources Science and Technology Journal Issue: 2 Vol. 33; ISSN 0963-0252
• Publisher: IOP PublishingCopyright Statement
• Country of Publication: United Kingdom
• Language: English