Simulations of radiatively cooled magnetic reconnection driven by pulsed power
Magnetic reconnection is an important process in astrophysical environments, as it reconfigures magnetic field topology and converts magnetic energy into thermal and kinetic energy. In extreme astrophysical systems, such as black hole coronae and pulsar magnetospheres, radiative cooling modifies the...
| Main Authors: | , , , , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Published: |
Cambridge University Press
2024
|
| Online Access: | https://hdl.handle.net/1721.1/155295 |
| _version_ | 1811097817909821440 |
|---|---|
| author | Datta, Rishabh Crilly, Aidan Chittenden, Jeremy P. Chowdhry, Simran Chandler, Katherine Chaturvedi, Nikita Myers, Clayton E. Fox, William R. Hansen, Stephanie B. Jennings, Chris A. Ji, Hantao Kuranz, Carolyn C. Lebedev, Sergey V. Uzdensky, Dmitri A. Hare, Jack D. |
| author_facet | Datta, Rishabh Crilly, Aidan Chittenden, Jeremy P. Chowdhry, Simran Chandler, Katherine Chaturvedi, Nikita Myers, Clayton E. Fox, William R. Hansen, Stephanie B. Jennings, Chris A. Ji, Hantao Kuranz, Carolyn C. Lebedev, Sergey V. Uzdensky, Dmitri A. Hare, Jack D. |
| author_sort | Datta, Rishabh |
| collection | MIT |
| description | Magnetic reconnection is an important process in astrophysical environments, as it reconfigures magnetic field topology and converts magnetic energy into thermal and kinetic energy. In extreme astrophysical systems, such as black hole coronae and pulsar magnetospheres, radiative cooling modifies the energy partition by radiating away internal energy, which can lead to the radiative collapse of the reconnection layer. In this paper, we perform two- and three-dimensional simulations to model the MARZ (Magnetic Reconnection on Z) experiments, which are designed to access cooling rates in the laboratory necessary to investigate reconnection in a previously unexplored radiatively cooled regime. These simulations are performed in GORGON, an Eulerian two-temperature resistive magnetohydrodynamic code, which models the experimental geometry comprising two exploding wire arrays driven by 20 MA of current on the Z machine (Sandia National Laboratories). Radiative losses are implemented using non-local thermodynamic equilibrium tables computed using the atomic code Spk, and we probe the effects of radiation transport by implementing both a local radiation loss model and 𝑃1/3
multi-group radiation transport. The load produces highly collisional, super-Alfvénic (Alfvén Mach number 𝑀𝐴≈1.5
), supersonic (Sonic Mach number 𝑀𝑆≈4−5
) strongly driven plasma flows which generate an elongated reconnection layer (Aspect Ratio 𝐿/𝛿≈100
, Lundquist number 𝑆𝐿≈400
). The reconnection layer undergoes radiative collapse when the radiative losses exceed the rates of ohmic and compressional heating (cooling rate/hydrodynamic transit rate = 𝜏−1cool/𝜏−1𝐻≈100
); this generates a cold strongly compressed current sheet, leading to an accelerated reconnection rate, consistent with theoretical predictions. Finally, the current sheet is also unstable to the plasmoid instability, but the magnetic islands are extinguished by strong radiative cooling before ejection from the layer. |
| first_indexed | 2024-09-23T17:05:06Z |
| format | Article |
| id | mit-1721.1/155295 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T17:05:06Z |
| publishDate | 2024 |
| publisher | Cambridge University Press |
| record_format | dspace |
| spelling | mit-1721.1/1552952024-09-20T04:07:49Z Simulations of radiatively cooled magnetic reconnection driven by pulsed power Datta, Rishabh Crilly, Aidan Chittenden, Jeremy P. Chowdhry, Simran Chandler, Katherine Chaturvedi, Nikita Myers, Clayton E. Fox, William R. Hansen, Stephanie B. Jennings, Chris A. Ji, Hantao Kuranz, Carolyn C. Lebedev, Sergey V. Uzdensky, Dmitri A. Hare, Jack D. Magnetic reconnection is an important process in astrophysical environments, as it reconfigures magnetic field topology and converts magnetic energy into thermal and kinetic energy. In extreme astrophysical systems, such as black hole coronae and pulsar magnetospheres, radiative cooling modifies the energy partition by radiating away internal energy, which can lead to the radiative collapse of the reconnection layer. In this paper, we perform two- and three-dimensional simulations to model the MARZ (Magnetic Reconnection on Z) experiments, which are designed to access cooling rates in the laboratory necessary to investigate reconnection in a previously unexplored radiatively cooled regime. These simulations are performed in GORGON, an Eulerian two-temperature resistive magnetohydrodynamic code, which models the experimental geometry comprising two exploding wire arrays driven by 20 MA of current on the Z machine (Sandia National Laboratories). Radiative losses are implemented using non-local thermodynamic equilibrium tables computed using the atomic code Spk, and we probe the effects of radiation transport by implementing both a local radiation loss model and 𝑃1/3 multi-group radiation transport. The load produces highly collisional, super-Alfvénic (Alfvén Mach number 𝑀𝐴≈1.5 ), supersonic (Sonic Mach number 𝑀𝑆≈4−5 ) strongly driven plasma flows which generate an elongated reconnection layer (Aspect Ratio 𝐿/𝛿≈100 , Lundquist number 𝑆𝐿≈400 ). The reconnection layer undergoes radiative collapse when the radiative losses exceed the rates of ohmic and compressional heating (cooling rate/hydrodynamic transit rate = 𝜏−1cool/𝜏−1𝐻≈100 ); this generates a cold strongly compressed current sheet, leading to an accelerated reconnection rate, consistent with theoretical predictions. Finally, the current sheet is also unstable to the plasmoid instability, but the magnetic islands are extinguished by strong radiative cooling before ejection from the layer. National Science Foundation (NSF) NNSA 2024-06-21T18:13:36Z 2024-06-21T18:13:36Z 2024-04 Article http://purl.org/eprint/type/JournalArticle 0022-3778 1469-7807 https://hdl.handle.net/1721.1/155295 Datta R, Crilly A, Chittenden JP, et al. Simulations of radiatively cooled magnetic reconnection driven by pulsed power. Journal of Plasma Physics. 2024;90(2):905900215. 10.1017/S0022377824000448 10.1017/s0022377824000448 Journal of Plasma Physics Creative Commons Attribution-Noncommercial-ShareAlike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Cambridge University Press Author |
| spellingShingle | Datta, Rishabh Crilly, Aidan Chittenden, Jeremy P. Chowdhry, Simran Chandler, Katherine Chaturvedi, Nikita Myers, Clayton E. Fox, William R. Hansen, Stephanie B. Jennings, Chris A. Ji, Hantao Kuranz, Carolyn C. Lebedev, Sergey V. Uzdensky, Dmitri A. Hare, Jack D. Simulations of radiatively cooled magnetic reconnection driven by pulsed power |
| title | Simulations of radiatively cooled magnetic reconnection driven by pulsed power |
| title_full | Simulations of radiatively cooled magnetic reconnection driven by pulsed power |
| title_fullStr | Simulations of radiatively cooled magnetic reconnection driven by pulsed power |
| title_full_unstemmed | Simulations of radiatively cooled magnetic reconnection driven by pulsed power |
| title_short | Simulations of radiatively cooled magnetic reconnection driven by pulsed power |
| title_sort | simulations of radiatively cooled magnetic reconnection driven by pulsed power |
| url | https://hdl.handle.net/1721.1/155295 |
| work_keys_str_mv | AT dattarishabh simulationsofradiativelycooledmagneticreconnectiondrivenbypulsedpower AT crillyaidan simulationsofradiativelycooledmagneticreconnectiondrivenbypulsedpower AT chittendenjeremyp simulationsofradiativelycooledmagneticreconnectiondrivenbypulsedpower AT chowdhrysimran simulationsofradiativelycooledmagneticreconnectiondrivenbypulsedpower AT chandlerkatherine simulationsofradiativelycooledmagneticreconnectiondrivenbypulsedpower AT chaturvedinikita simulationsofradiativelycooledmagneticreconnectiondrivenbypulsedpower AT myersclaytone simulationsofradiativelycooledmagneticreconnectiondrivenbypulsedpower AT foxwilliamr simulationsofradiativelycooledmagneticreconnectiondrivenbypulsedpower AT hansenstephanieb simulationsofradiativelycooledmagneticreconnectiondrivenbypulsedpower AT jenningschrisa simulationsofradiativelycooledmagneticreconnectiondrivenbypulsedpower AT jihantao simulationsofradiativelycooledmagneticreconnectiondrivenbypulsedpower AT kuranzcarolync simulationsofradiativelycooledmagneticreconnectiondrivenbypulsedpower AT lebedevsergeyv simulationsofradiativelycooledmagneticreconnectiondrivenbypulsedpower AT uzdenskydmitria simulationsofradiativelycooledmagneticreconnectiondrivenbypulsedpower AT harejackd simulationsofradiativelycooledmagneticreconnectiondrivenbypulsedpower |