Microturbulence

Nowadays, Microturbulence is a topic that attracts the attention of many people around the world. From its origins to its impact on today's society, Microturbulence has been the subject of numerous debates and has aroused great interest in different fields. Whether due to its historical relevance, its influence on popular culture or its importance in science and technology, Microturbulence is a phenomenon that continues to intrigue experts and fans alike. In this article, we will explore different aspects of Microturbulence and analyze its impact in different areas, in order to better understand its meaning and its reach in contemporary society.

Microturbulence is a form of turbulence that varies over small distance scales. (Large-scale turbulence is called macroturbulence.)

Stellar

Microturbulence is one of several mechanisms that can cause broadening of the absorption lines in the stellar spectrum. Stellar microturbulence varies with the effective temperature and the surface gravity.

The microturbulent velocity is defined as the microscale non-thermal component of the gas velocity in the region of spectral line formation. Convection is the mechanism believed to be responsible for the observed turbulent velocity field, both in low mass stars and massive stars. When examined by a spectroscope, the velocity of the convective gas along the line of sight produces Doppler shifts in the absorption bands. It is the distribution of these velocities along the line of sight that produces the microturbulence broadening of the absorption lines in low mass stars that have convective envelopes. In massive stars convection can be present only in small regions below the surface; these sub-surface convection zones can excite turbulence at the stellar surface through the emission of acoustic and gravity waves. The strength of the microturbulence (symbolized by ξ, in units of km s−1) can be determined by comparing the broadening of strong lines versus weak lines.

Magnetic nuclear fusion

Microturbulence plays a critical role in energy transport during magnetic nuclear fusion experiments, such as the Tokamak.

References

  1. ^ De Jager, C. (1954). "High-energy Microturbulence in the Solar Photosphere". Nature. 173 (4406): 680–1. Bibcode:1954Natur.173..680D. doi:10.1038/173680b0. S2CID 4188420.
  2. ^ Montalban, J.; Nendwich, J.; Heiter, U.; Kupka, F.; et al. (1999). "The Effect of the microturbulence parameter on the Color-Magnitude Diagram". Reports on Progress in Physics. 61 (S239): 77–115. Bibcode:2007IAUS..239..166M. doi:10.1017/S1743921307000361.
  3. ^ Cantiello, M. et al. (2008) (15 February 2024). "On the origin of Microturbulence in hot stars" (PDF). {{cite journal}}: Cite journal requires |journal= (help)CS1 maint: numeric names: authors list (link)
  4. ^ Cantiello, M. et al. (2009); Langer, N.; Brott, I.; De Koter, A.; Shore, S. N.; Vink, J. S.; Voegler, A.; Lennon, D. J.; Yoon, S.-C. (2009). "Sub-surface convection zones in hot massive stars and their observable consequences". Astronomy and Astrophysics. 499 (1): 279. arXiv:0903.2049. Bibcode:2009A&A...499..279C. doi:10.1051/0004-6361/200911643. S2CID 55396719.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  5. ^ Briley, Michael (July 13, 2006). "Stellar Properties from Spectral Lines: Introduction". University of Wisconsin. Archived from the original on November 23, 2007. Retrieved 2007-05-21.
  6. ^ Nevins, W.M. (August 21, 2006). "The Plasma Microturbulence Project". Lawrence Livermore National Laboratory. Archived from the original on July 20, 2011. Retrieved 2007-05-21.

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