"Adlam and Allen and Davis, Lust, and Schluter have studied nonlinear plane-waves, propagating normal to the magnetic field, in a cold plasma. One solution of particular interest is a solitary wave, or single pulse. We present a method for solving the analogous problem for a plasma with finite temperature, in the limiting case where the amplitude of the wave is small and where, consequently, the width of the waver is very large."

Both in magnetohydrodynamic shocks and in accelerated partially ionized gas flow across a magnetic field, space charge separation occurs that establishes very large electric fields in the direction of motion. The width of the current layers associated with the acceleration is never less than the electron Larmor radius with no collisions and is broadened by electron collisions to a width solely determined by the effective resistivity. The electrons gain an energy regardless of collisions equal to the electric potential difference across the layer. This potential corresponds to the change in kinetic energy of mass motion per ion. For slightly ionized gases, the additional stress of neutral ion collisions within the layer can make the electric potential and hence gain in electron energy very large for only modest changes in mass velocity. Hence ionization may occur when the change in kinetic energy of the ions is small compared to the ionization potential.

"A finite difference approximation to a non-linear set of parabolic differential equations arising in shallow water theory is given. These difference equations were used to determine the shape and rate of propagation of a hum of fluid down a channel of constant depth. The hump of fluid was found to spread instead of steepen, as is the case in the usual shallow water theory."

This report follows experiments concerned with a particular proposal or set of related proposals of means for the production of plasma with density above 10-11 particles per cm-3 with a temperature of the order of a few electron volts.

Monoclinic FeSO4·7H2O is the stable solid phase between -1.82° and 56.6° C in contact with a saturated water solution of FeSO4. It occurs in nature as an oxidation product of Fe-containing sulfides an is called melanterite. FeSO4·7H2O belongs to a series of compounds Me2+SO4·nH2O, where Mn2+ is a cation with an approximate ionic radius of 0.7Å. The 1-, 4- and 5-hydrates are known to crystalize each in only one form, whereas the hexa- and the heptahydrates occur both in two different forms. The crystal structure of the tetragonal NiSO4·6H2O; Zalkin, Ruben and Templeton reported the structure of the monoclinic CoSO·6H2O. Of the structure of the heptahydrates but one was described: the orthorhombic form of NiSO4·7H2O. No details were known about one of the monoclinic heptahydrates, though Leonhardt and Ness published the cell constants and the space group of FeSO4·7H2O.. In addition they stated essentially correct positional parameters for the sulfur atom and gave the correct positions of the iron atoms. The present investigation has been undertaken as part of an extensive study of salt hydrates. A preliminary account has been published before.

"We compute the equilibrium configuration of a collision-free plasma contained in an axially symmetric magnetic field. The plasma is characterized by a non-scalar pressure tensor which is obtained from a microscopic distribution function in a form suggested b the guiding center approximation. The solution is calculated in the limit where the ratio of the width to the length of the plasma region and the ratio of the gas to the magnetic pressure are both small. Boundary values at the midplane as well as the shape of the plasma appear as arbitrary parameters in the solution. We give the solution to a corresponding scalar pressure problem for comparison."