National Academies Press: OpenBook

Plasma Science: From Fundamental Research to Technological Applications (1995)

Chapter: Terrestrial Observation Networks

« Previous: In Situ Observations
Suggested Citation:"Terrestrial Observation Networks." National Research Council. 1995. Plasma Science: From Fundamental Research to Technological Applications. Washington, DC: The National Academies Press. doi: 10.17226/4936.
×
Page 116

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

SPACE PLASMAS 116 In Situ Experiments The previous section concentrated on passive observations of natural processes acting in space. It is also possible to conduct in situ, or active, experiments whereby artificial injections of charged particles, neutral gases, or electro-magnetic waves are used to alter natural processes or to stimulate new processes in the ambient plasma medium. It is possible to contemplate a rich selection of potential in situ experiments capable of exploring new areas of plasmas in space. NASA is the principal sponsor of such work, but for the past four years, as a matter of policy, NASA has restricted its funding to those projects that explore natural processes, rather than artificially induced behaviors. However, since many of the results of the latter types of experiments have important implications for plasmas in different space environments, it is hoped that this policy will be reviewed. Here we give brief outlines of some possible in situ experiments that have special merit. Space vehicles offer the promise of performing three-dimensional experiments in unbounded plasmas with varying mixtures of neutral gas. These can be done on a scale size that should make the instrumentation easy to build. In addition, the relevant time scales are microseconds or longer, which are easily measured and recorded. In spite of these advantages, plasma experiments in space have not been easy to perform. The principal reasons are that diagnostic instruments are difficult to place accurately and the space platforms that carry them may be big enough to interfere with the experiment. By using space platforms with suitable resources, it should be possible to investigate steady-state diamagnetic cavities in space plasmas. In this situation, the plasma effusion speed from its source can be made larger than the diffusion speed of the magnetic field. A complex region of low magnetic field is maintained by plasma pressure against the flowing ambient plasma and ambient magnetic field. This is an unstable situation, which opens the way to investigation of various types of instabilities. It is likely that these will reveal the presence of many new high-beta plasma-magnetic field interactions that depend on various plasma and magnetic field parameters. Magnetic field interactions, analogous to the solar wind-geomagnetic field coupling, can also be anticipated as the capability to construct and operate large magnets in space evolves. These experiments, involving a variety of plasmas and magnetic field configurations, will have relevance to a wide range of astrophysical situations. Terrestrial Observation Networks Support for the existing standard observatories, which provide the long- term monitoring of fundamental parameters of the upper atmosphere, ionosphere, and magnetosphere, is a key part of a scientific strategy that recognizes the importance of time series data relating to the geophysical environment. Optical, radar,

Next: Laboratory Experiments »
Plasma Science: From Fundamental Research to Technological Applications Get This Book
×
Buy Paperback | $65.00 Buy Ebook | $54.99
MyNAP members save 10% online.
Login or Register to save!
Download Free PDF

Plasma science is the study of ionized states of matter. This book discusses the field's potential contributions to society and recommends actions that would optimize those contributions. It includes an assessment of the field's scientific and technological status as well as a discussion of broad themes such as fundamental plasma experiments, theoretical and computational plasma research, and plasma science education.

  1. ×

    Welcome to OpenBook!

    You're looking at OpenBook, NAP.edu's online reading room since 1999. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website.

    Do you want to take a quick tour of the OpenBook's features?

    No Thanks Take a Tour »
  2. ×

    Show this book's table of contents, where you can jump to any chapter by name.

    « Back Next »
  3. ×

    ...or use these buttons to go back to the previous chapter or skip to the next one.

    « Back Next »
  4. ×

    Jump up to the previous page or down to the next one. Also, you can type in a page number and press Enter to go directly to that page in the book.

    « Back Next »
  5. ×

    To search the entire text of this book, type in your search term here and press Enter.

    « Back Next »
  6. ×

    Share a link to this book page on your preferred social network or via email.

    « Back Next »
  7. ×

    View our suggested citation for this chapter.

    « Back Next »
  8. ×

    Ready to take your reading offline? Click here to buy this book in print or download it as a free PDF, if available.

    « Back Next »
Stay Connected!