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1. In the national pulse MHD generators with power from 10 to 600 MW, solid plasmagenerating propellants (SPPs) are used, which contain dibasic ballistite powders with an aluminum content of up to 21% (in mass) and an easily ionized seed like cesium or potassium nitrates (1-3). New SPPs should have increased values of the energy complex σv 2 (σ is the electrical conductivity, and v is the velocity) and the heat content of combustion products, which depends on their heat capacitance at constant pressure and the calorific power of the fuel. The value of the complex σv 2 depends mainly on temperature, while the heat capacitance is related to the combustionproduct composition and their degree of dissociation, which depends on the oxidizer excess factor α. The prelimi� nary study of new SPP compositions shows the possi� bility of a substantial increase in both the complex σv 2 and the coefficient α.

The sensitivity of the albedo electron method in density determinations on some P/M materials is equal to 0.1%. The method offers an accurate and rapid nondestructive means of examining the distribution of porosity in specimens. Use of an accelerator in determinations by this method ensures an appreciable depth of control, enables the size of the control zone to be varied, and increases control rate tens of times compared with the hydrostatic weighing technique.

The paper reports the results of measurements of the space-time properties of space charges in polymethyl methacrylate (PMMA) disks after a high-energy injection of electrons. Investigations by four independent methods (i.e., the through-probing, current, electrostatic, and sectioning methods) reveal that, first, the charge distribution is radially inhomogeneous regardless of the small ratio of the specimen thickness to diameter (1/10 to 1/30) and, second, space-time relaxation of charges occurs in a singular manner at diameters of 32, 65, and 130 mm.