摘要:

The three‐body volume recombination coefficient for neutral atoms A of nitrogen, oxygen, and hydrogen in their parent molecular gases M has been measured over a pressure range of one to ten millimeters at 300°K. The observations fit a reaction of the formA+A+[M]→k1(A)A2*+[M],wherek1(A), the rate constant, is found to be, respectively,k1(N) = 1.5 × 10−32cm6/sec,k1(O) = 0.45 × 10−32cm6/sec, andk1(H) = 6.5 × 10−32cm6/sec. These determinations have an experimental fluctuation of ± 20%. Observations of the electron spin resonance (ESR) signal from the ground state of the atoms allowed direct determination of the atomic density. Measurements were made in a stream of flowing gas which carried the atoms through the ESR detection cavity. An atomic concentration of 1014− 1016cm−3could be obtained in a CW electrodeless discharge. Surface recombination was inhibited by coating wall surfaces with a thin film of concentrated H2SO4. The work also includes some preliminary measurements of surface atomic recombination coefficients.

ISSN:0031-9171    

DOI:10.1063/1.1724443

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

Formulas are derived for the collisional contributions to the pressure tensor and heat‐flux vector in fluids composed of molecules which interact with impulsive forces. An approximation scheme is then employed to obtain ``zero‐order'' estimates of the viscosity and thermal conductivity coefficients for various molecular models. The models considered are rough spherical and rigid convex molecular ``cores'' surrounded by potential staircases. The viscosity and thermal conductivity coefficients determined for the special case of cores surrounded by a square‐well attractive potential are found to vary approximately asT1/2eA/Tat ordinary liquid temperatures. Calculations are also presented of the variations of the transport coefficients with molecular shape and eccentricity parameters.

ISSN:0031-9171    

DOI:10.1063/1.1724444

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

The compressibility of nitrous oxide (N2O) has been measured with high precision from 0° to 150°C and over a density range of about 18 to 180 amagat. The agreement with results of others using somewhat different experimental techniques is good. The virial coefficients are calculated, and the intermolecular potential of nitrous oxide calculated from the second virial coefficient for several forms of force laws, both spherical and nonspherical. A comparison with the physically similar molecule carbon dioxide is made.

ISSN:0031-9171    

DOI:10.1063/1.1724445

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

Incoherent scattering is determined by the spectral density of electron‐density fluctuations. This quantity has previously been calculated for a plasma in thermal equilibrium. We have extended the theory to include spatially homogeneous nonequilibrium states of a hot plasma. An elementary derivation of the previous results and the new results is given in terms of dressed test particles. Numerical calculations have been carried out for a plasma with hot electrons and cold ions, and for a plasma in which the electrons have a net drift relative to the ions.

ISSN:0031-9171    

DOI:10.1063/1.1724446

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

A system is described which produces a steady‐state helium plasma with greater than 95% ionization. The primary plasma is generated in a modified Phillips ion gauge discharge and diffuses along a magnetic field (B∼ 1 kG) through a region in which neutral particles are preferentially removed. In the downstream region a plasma density of ∼2 × 1013cm−3and ion temperatures up to 10 eV have been achieved. The present paper describes the over‐all physical assembly, the operating characteristics of the system, and the nature of the plasma that is produced. In addition, a discussion of processes believed important in its operation is given.

ISSN:0031-9171    

DOI:10.1063/1.1724447

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

Techniques and results are given for various measurements made on a highly ionized helium plasma in a steady‐state plasma system (which employs a longitudinal magnetic field of approximately 1 kilogauss). Neutral‐particle pressures ranged from about 3 × 10−4mm Hg near the source to about 10−5mm Hg in the downstream region. Spectroscopic measurements showed principal impurities were C, N, and O ions (up to C3+, N4+, and O4+states). Doppler broadening measurements of He+&lgr;4686 revealed ion temperatures up to 10 eV. Probe measurements indicated electron temperatures up to 20 eV and maximum ion densities of a little over 1013cm−3. Microwave transmission measurements (at &lgr; = 4 mm and 8 mm) gave supporting evidence that the electron density exceeds 1013cm.

ISSN:0031-9171    

DOI:10.1063/1.1724448

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

Plasma acceleration by an rf field gradient has been observed for both 140 and 330 Mc fields. The kinetic‐energy gain of the accelerated ions varied inversely with the applied frequency. Comparison with theory indicates that in the interaction region most of the accelerated plasma has a resonant frequency near the applied frequency. The collision frequency which limits the acceleration in the test apparatus is calculated to be 6 Mc.

ISSN:0031-9171    

DOI:10.1063/1.1724449

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

Equilibrium solutions of an electron beam injected into a plasma are considered. This is a preliminary step in studying the stability of the so‐called ``E layer'' of the Astron thermonuclear reactor. The model consists of a plane sheet of streaming electrons in a homogeneous plasma. Equilibrium solutions are obtained from the collisionless Boltzmann equations for three fluids: one of stream electrons, another of plasma electrons, and a third of plasma ions. Two important cases are treated in this manner: cold plasma and cold beam. The distribution of beam electrons, plasma ions, and plasma electrons are disclosed.

ISSN:0031-9171    

DOI:10.1063/1.1724450

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

A simple ``single‐term'' stability criterion is obtained for hydromagnetic equilibria with multipolar fields. It replaces an earlier criterion in which it is necessary to evaluate the ratio of two infinite determinants. It corresponds to the criterion recently developed for arbitrary equilibria by Mercier, Bineau, and ourselves but is tailored to a specific geometry.

ISSN:0031-9171    

DOI:10.1063/1.1724451

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

The induced magnetic field is neglected owing to the small conductivity of the fluid. The effect of the magnetic field upon the flow is also assumed to be so small that it can be treated as a perturbation. Thus, the first‐order correction to the nonmagnetic potential flow is obtained by a simple perturbation technique. The solution indicates existence of a nondiffusive, vortical, velocity deficiency which extends indefinitely downstream of the cylinder. The flow field at great distances is also reconsidered as a problem of singular perturbation.

ISSN:0031-9171    

DOI:10.1063/1.1724452

出版商:AIP    

年代:1962

数据来源: AIP