Title: Computational investigation of ion cyclotron heating on Proto-MPEX

Abstract

Ion cyclotron heating (ICH) on the Prototype Material Plasma Exposure eXperiment (Proto-MPEX) is to be accomplished using the “beach-heating” technique. Beach heating has not been previously demonstrated to efficiently heat core ions at the high electron density values present in Proto-MPEX. This work numerically investigates the wave propagation characteristics of the ICH region on Proto-MPEX to explore avenues for efficient core ion heating. The analysis reveals that finite electron temperature effects are required to predict core ion heating. Cold plasma dispersion analysis and full-wave simulations show that the inertial Alfvén wave (IAW) is restricted from coupling power into the core plasma because (1) the group velocity is too shallow for its energy to penetrate into the core before damping in the periphery and (2) when operating in a magnetic field where ω/ω_ci ≳ 0.7, the IAW is cut off from the core plasma by the Alfvén resonance. However, including kinetic effects shows that the kinetic Alfvén wave (KAW) can propagate in the electron temperature regime in Proto-MPEX. Full-wave simulations show that when the electron temperature is increased to T_e > 2 eV and the edge electron density is sufficiently high n_eedge > 1 × 10¹⁷ m^-3, ion power absorption inmore » the core increases substantially (≈25% of total power). Here, the increase in ion power absorption in the core is attributed to the propagation of the KAW. Calculations of electron and ion power absorption show that the electron heating is localized around the Alfvén resonance, while the ion heating is localized at the fundamental ion cyclotron resonance.« less

Authors:

Piotrowicz, Pawel A.  ^[1];

• Search DOE PAGES for author "Piotrowicz, Pawel A."
• Search DOE PAGES for ORCID "0000-0001-7871-6971"

Goulding, Richard H.  ^[2];

• Search DOE PAGES for author "Goulding, Richard H."
• Search DOE PAGES for ORCID "0000-0002-1776-7983"

Caneses, Juan F.  ^[2];

• Search DOE PAGES for author "Caneses, Juan F."
• Search DOE PAGES for ORCID "0000-0001-6123-2081"

Green, D. L.  ^[2];

• Search DOE PAGES for author "Green, D. L."
• Search DOE PAGES for ORCID "0000-0003-3107-1170"

Caughman, John B. O.  ^[2];

• Search DOE PAGES for author "Caughman, John B. O."
• Search DOE PAGES for ORCID "0000-0002-0609-1164"

Lau, Cornwall  ^[2];

• Search DOE PAGES for author "Lau, Cornwall"
• Search DOE PAGES for ORCID "0000-0002-8576-5867"

Rapp, Juergen  ^[2];

• Search DOE PAGES for author "Rapp, Juergen"
• Search DOE PAGES for ORCID "0000-0003-2785-9280"

Ruzic, David N. ^[3]

---

+ Show Author Affiliations

1. Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); University of Illinois Urbana-Champaign, IL (United States)
2. Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
3. University of Illinois Urbana-Champaign, IL (United States)

Publication Date:

Thu Mar 21 00:00:00 EDT 2019

Research Org.:

Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:

USDOE Office of Science (SC)

OSTI Identifier:

1649631

Alternate Identifier(s):

OSTI ID: 1502273

Grant/Contract Number:  

AC05-00OR22725

Resource Type:

Accepted Manuscript

Journal Name:

Physics of Plasmas

Additional Journal Information:

Journal Volume: 26; Journal Issue: 3; Journal ID: ISSN 1070-664X

Publisher:

American Institute of Physics (AIP)

Country of Publication:

United States

Language:

English

Subject:

70 PLASMA PHYSICS AND FUSION TECHNOLOGY; Frequency measurement; wave model; wave mechanics; dispersion function; plasma waves; electron density; dielectric properties