Enabling Discoveries in Heliospheric Science through Laboratory Plasma Experiments

2010

Plasma experiments in laboratory settings offer the opportunity to address fundamental aspects of the solar dynamo and magnetism in the solar atmosphere. Experiments are currently under construction that can investigate the self-generation of magnetic fields and related processes in large, weakly magnetized, fast flowing, and hot (conducting) plasmas. These and future experiments will probe questions that are of crucial importance to heliophysics in the solar interior, atmosphere and wind. Uniquely, laboratory plasma experiments coupled with theoretical explorations can serve to calibrate the simulation codes which are being used to understand the solar dynamo, magnetic reconnection and flares in the solar atmosphere, the nature of CMEs, and the interactions between planetary magnetospheres and the solar wind. Laboratory plasma experiments are likely to contribute new understanding complementary to the traditional observational and modeling approach normally used by space physicists. We argue here that ground-based laboratory experiments have direct connections to NASA based missions and NSF programs, and that a small investment in laboratory heliophysics may have a high payoff. We will use the Madison Plasma Dynamo Experiment (MPDX) 1 as an example, but advocate here for broad involvement in community-scale plasma experiments. 1 This work builds upon excitement in recent years of using liquid metals to study dynamos and will extend these studies to more astrophysically relevant parameters. Use of a plasma for such experiments allows the magnetic Reynolds number (the dimensionless parameter governing self-excitation of magnetic fields) to be approximately a factor of 10 larger than in liquid metal experiments. These experiments will be the first to investigate self-excited dynamos in a plasma, the state of matter that makes up most naturally occurring astrophysical dynamos.

arXiv: Space Physics, 2020

Magnetic reconnection underlies many explosive phenomena in the heliosphere and in laboratory plasmas. The new research capabilities in theory/simulations, observations, and laboratory experiments provide the opportunity to solve the grand scientific challenges summarized in this whitepaper. Success will require enhanced and sustained investments from relevant funding agencies, increased interagency/international partnerships, and close collaborations of the solar, heliospheric, and laboratory plasma communities. These investments will deliver transformative progress in understanding magnetic reconnection and related explosive phenomena including space weather events.

arXiv (Cornell University), 2022

Owing to the ever-present solar wind, our vast solar system is full of plasmas. The turbulent solar wind, together with sporadic solar eruptions, introduces various space plasma processes and phenomena in the solar atmosphere all the way to the Earth's ionosphere and atmosphere and outward to interact with the interstellar media to form the heliopause and termination shock. Remarkable progress has been made in space plasma physics in the last 65 years, mainly due to sophisticated in-situ measurements of plasmas, plasma waves, neutral particles, energetic particles, and dust via space-borne satellite instrumentation. Additionally high technology ground-2 To appear in IEEE Transactions on Plasma Science

Symposium - International Astronomical Union

We summarize the discussion of the current status and future prospects of space and astrophysical plasma research prepared by the Panel on Space and Astrophysical plasmas, a part of the study on Physics administered by the National Research Council of the National Academy of Sciences. The Study on Physics is chaired by W. Brinkman of Bell Laboratories and will be completed in 1984.

Journal of Plasma Physics, 2015

The Wisconsin Plasma Astrophysics Laboratory (WiPAL) is a flexible user facility designed to study a range of astrophysically relevant plasma processes as well as novel geometries that mimic astrophysical systems. A multi-cusp magnetic bucket constructed from strong samarium cobalt permanent magnets now confines a$10~\text{m}^{3}$, fully ionized, magnetic-field-free plasma in a spherical geometry. Plasma parameters of$T_{e}\approx 5$to$20~\text{eV}$and$n_{e}\approx 10^{11}$to$5\times 10^{12}~\text{cm}^{-3}$provide an ideal testbed for a range of astrophysical experiments, including self-exciting dynamos, collisionless magnetic reconnection, jet stability, stellar winds and more. This article describes the capabilities of WiPAL, along with several experiments, in both operating and planning stages, that illustrate the range of possibilities for future users.

Proceedings of the International Astronomical Union, 2005

Commission 49 covers research on the solar wind, shocks and particle acceleration, both transient and steady-state, e.g., corotating, structures within the heliosphere, and the termination shock and boundary of the heliosphere. During the last three years there was considerable progress made in studies of solar energetic particles, compositional and other signatures in the heliosphere, solar wind pickup ions, the termination shock, which was finally crossed by a spacecraft, and the boundary between the heliosphere and interstellar medium, and in solar wind modeling and space weather. These topics have been summarized here in five articles, each with extensive references that will guide the reader who wants further details. Observations from the following spacecraft have extensively used during this period: Ulysses, Cassini, Voyager 1 and 2, MESSENGER, ACE, Genesis, SOHO, Wind, and RHESSI.

2009

Plasma and the Universe, 1988

Magnetohydrodynamics (MHD) is a fairly recent extension of the field of fluid mechanics. While much remains to be done, it has successfully been applied to the contemporary field of heliospheric space plasma research to evaluate the 'macroscopic picture' of some vital topics via the use of conducting fluid equations and numerical modeling and simulations. Some representative examples from solar and interplanetary physics are described to demonstrate that the continuum approach to global problems (while keeping in mind the assumptions and limitations therein) can be very successful in providing insight and large scale interpretations of otherwise intractable problems in space physics. * Paper dedicated to Professor Hannes Alfv6n on the occasion of his 80th birthday, 30 May 1988.

Proceedings of the International Astronomical Union, 2015

After a little more than forty years of work related to the interplanetary plasma and the heliosphere the IAU's Commission 49 was formally discontinued in 2015. The commission started its work when the first spacecraft were launched to measure the solar wind in–situ away from Earth orbit, both inward and outward from 1 AU. It now hands over its activities to a new commission during an era of space research when Voyager 1 measures in–situ the parameters of the local interstellar medium at the edge of the heliosphere. The commission will be succeeded by C.E3 with a similar area of responsibility but with more focused specific tasks that the community intends to address during the coming several years. This report includes a short description of the motivation for this commission and of the historical context. It then describes work from 2012 to 2015 during the present solar cycle 24 that has been the weakest in the space era so far. It gave rise to a large number of studies on sol...

The Astrophysical Journal, 2011

Sound numerical modeling is capable of providing important predictive information about the solar wind interaction with the local interstellar medium. The results of our three-dimensional simulation show a good agreement with Voyager observations from 2007 to 2010. We analyze the termination shock properties at the Voyager crossing points and juxtapose them with the observed data. The heliospheric current sheet structure in the inner heliosheath is examined.