D. J. BenDaniel

NONEQUILIBRIUM IONIZATION IN A HIGH-PRESSURE CESIUM-HELIUM TRANSIENT DISCHARGE

Voltage gradient vs current density measurements of a discharge in helium seeded with cesium are given over the range of current densities of 0.1 to 20 A/cm2, cesium densities of 4.0 × 1013 to 2.8 × 1015/cm3 and at helium densities of 2.5 and 5.0 × 1018/cm3. Readings are taken at a time (50 μsec) sufficiently long to allow electron temperature and ionization to be established but short in comparison with the heating time of the gas. Results compare quite favorably with the theory of nonequilibrium ionization, also discussed. A positive resistance characteristic is observed in most of the regime.

Concentration in the Venture Capital Industry

This article examines historical data characterizing the U.S. venture capital industry from 1961 to the present. It shows that concentration has existed in the industry for at least a decade, and this concentration continues to grow and become more pronounced. Capital is raised by an elite few of the venture capital firms currently in operation. This group of very large venture capital firms has consistently shown an IRR exceeding that of the rest of the industry. In general, these larger firms tend to focus on later stage deals. In what might be characterized as a disequilibrium, venture capital IRRs in later stage deals have been higher than those captured by early stage deals. Factors maintaining this disequilibrium are discussed along with the potential industry implications associated with concentration.

CYCLOTRON RESONANCE PROPULSION SYSTEM

A desciiption is given of a system in which plasma is generated and accelerated by a combination of a d-c magnetic field and a c-w, high-frequency electromagnetic field. Theoretical analysis of the processes by which energy is transferred from the electromagnetic field to the plasma is included. Some practical considerations concerning application of this system are also mentioned. The theoretical conclusion is reached that under proper conditions energy can be efficiently transferred to the plasma. A further conclusion is that the system operation is most favorable at power levels of 50 kw and more. (auth)

Plasma potential in a magnetic mirror system

An estimate is made of the plasma potential created by the more rapid initial loss of electrons from magnetic mirror confinement. The effects of this potential on the mirror ratio of the system is discussed. Calculations of this potential as a function of position in the magnetic mirror system are presented for two cases of interest.

Electron Conductivity at Cyclotron Resonance

The electron conductivity of an ionized gas for electromagnetic radiation of frequency omega circularly polarized in the right-handed sense propagating along a uniform mag netic field is estimated for a plasma of nonzero temperature. Collisions are included. It is also shown that in the limit where the collision frequency becomes small and omega = omega /sub c/ there remains a nonvanishing real part of the form sigma = (ne/sup 2//km) (1/v/sub th/) alpha where k is the propagation constant, v/sub th/ is the speed which characterizes the thermal spread of the electrons velocity component in the longitudinal direction and alpha is a number of order unity relatively insensitive to the actual form of the electron distribution in longitudinal speeds. (auth)

An econometric analysis of energy over the next 75 years

Abstract Preliminary results from an econometric model with a 75-year time-horizon to determine base-load power generation mix is described. A number of conventional, evoloutionary and speculative generation systems are considered, together with constraints imposed by fuel availability and technical development times.

Approximate Asymptotic Speed Distribution of Ions in a "Long" Magnetic Mirror System

The Rosenbluth, MacDonald, and Judd equation used for calculating the ion loss rates from a long magnetic mirror system is altered for obtaining an approximate asymptotic distribution of the ions. The equation is reduced by invoking the fact that the Rosenbluth potential is very nearly isotropic when the asymptotic angular distribution is attained. The asymptotic speed forms obtained from these computations are graphically given for several mirror ratios. (N.W.R.)

MATCHING CONDITIONS AT GRADUAL PLASMA BOUNDARIES

The problem of matching the solutions of the wave equation at gradual plasma boundaries has been considered extensively by several authors. In this note certain of the results are summarized for various simple forms of variation of the isotropic dielectric constant for normally incident waves in the boundary region. Contour graphs of the amplitude of the reflection coefficient as a function of boundary parameters are presented. (auth)

Implications of Einstein-Weyl Causality on Quantum Mechanics

An investigation of the topological consequences of Einstein-Weyl causality by others has shown that a denumerable space-time would be admitted, but they were left with an experimentally unresolvable question regarding the nature of the physical line E, e.g., whether E = R, the real line of mathematics. We propose a nonstandard constructible set-theoretical foundation and find it indeed provides a dense, denumerable space-time that still allows physical functions and their derivatives to be continuous. We show here that this leads to a novel approach to quantum mechanics and, in addition, has important implications for relational space-time and the avoidance of physical infinities.

The Unreasonable Effectiveness of Mathematics in Physics

Following a suggestion of Wigner, we look for a deep connection between mathematics and physics. Accordingly, a mathematical foundation is proposed which leads to a field theory. In this theory, fields are constructed solely from biunique eigenfunction pieces, each piece obtained from the same general variational expression akin to least action. We show that this piecewise construction does indeed produce a finite unit of action and quantum statistics. The fundamental concept of “definability” of fields is introduced. A definable field is free of paradoxes.