Theses - Dept. of Physics
http://hdl.handle.net/1721.1/7608
2017-03-29T05:28:33ZInertial tearing modes in magnetically-confined plasmas
http://hdl.handle.net/1721.1/107542
Inertial tearing modes in magnetically-confined plasmas
Montag, Peter Katsumi
In this thesis, I analyzed the behavior of the plasma instability known as the tearing mode in parameter regimes relevant to magnetically-confined fusion plasmas. This included a derivation of the relevant equations and a method of solving them using Fourier analysis. This method allowed the derivation of several analytic results and efficient calculation of numeric results about the growth rates and frequencies of the analyzed modes, and demonstrated the existence of a second type of unstable tearing mode related to electron inertia. The results of the analysis of this inertial mode proved consistent with experimental data on the tearing mode from JET, and suggests further analysis in the nonlinear regime to verify this consistency.
Thesis: S.M., Massachusetts Institute of Technology, Department of Physics, 2016.; Cataloged from PDF version of thesis.; Includes bibliographical references (pages 91-92).
2016-01-01T00:00:00ZThe thermal conductivity of magnesium between one and four degrees Kelvin
http://hdl.handle.net/1721.1/107504
The thermal conductivity of magnesium between one and four degrees Kelvin
Sharkoff, Eugene G. (Eugene Gibb)
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Physics, 1952.; Includes bibliographical references (leaf 21).
1952-01-01T00:00:00ZFluid dynamics in action
http://hdl.handle.net/1721.1/107318
Fluid dynamics in action
Glorioso, Paolo
In this thesis we formulate an effective field theory for nonlinear dissipative fluid dynamics. The formalism incorporates an action principle for the classical equations of motion as well as a systematic approach to thermal and quantum fluctuations around the classical motion of fluids. The dynamical degrees of freedom are Stuckelberg-like fields associated with diffeomorphisms and gauge transformations, and are related to the conservation of the stress tensor and a U(1) current if the fluid possesses a charge. This inherently geometric construction gives rise to an emergent "fluid space-time", similar to the Lagrangian description of fluids. We develop the variational formulation based on symmetry principles defined on such fluid space-time. Through a prescribed correspondence, the dynamical fields are mapped to the standard fluid variables, such as temperature, chemical potential and velocity. This allows to recover the standard equations of fluid dynamics in the limit where fluctuations are negligible. Demanding the action to be invariant under a discrete transformation, which we call local KMS, guarantees that the correlators of the stress tensor and the current satisfy the fluctuation-dissipation theorem. Local KMS invariance also automatically ensures that the constitutive relations of the conserved quantities satisfy the standard constraints implied e.g. by the second law of thermodynamics, and leads to a new set of constraints which we call generalized Onsager relations. Requiring the above properties to hold beyond tree-level leads to introducing fermionic partners of the original degrees of freedom, and to an emergent supersymmetry. We also outline a procedure for obtaining the effective field theory for fluid dynamics by applying the holographic Wilsonian renormalization group to systems with a gravity dual.
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Physics, 2016.; Cataloged from PDF version of thesis.; Includes bibliographical references (pages 207-213).
2016-01-01T00:00:00ZThreshold electrodisintegration of the deuteron at high momentum transfer
http://hdl.handle.net/1721.1/107303
Threshold electrodisintegration of the deuteron at high momentum transfer
Schmitt, William Michael, 1965-
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 1993.; Includes bibliographical references (p. 201-206).
1993-01-01T00:00:00Z