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1 Dec 1984

Volume 56, Issue 11, pp. 3039-3366

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A comparison of scalar multipole expansions

John P. Wikswo and Kenneth R. Swinney

J. Appl. Phys. 56, 3039 (1984); http://dx.doi.org/10.1063/1.333885 (11 pages) | Cited 14 times

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Scalar multipole expansions have been widely used in many areas of physics as general solutions to Laplace’s equation. However, comparison of work by different authors is often complicated by the existence of several different forms of multipole expansions in different coordinate systems. In this paper we compare the spherical harmonic, Taylor’s series, direction cosine and traceless tensor expansions and present models of dipole configurations that in the proper limit give the individual multipoles. These pictures simplify the comparison of the series and aid in interpretation of the various multipole moments.
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02.30.Mv Approximations and expansions
02.30.Jr Partial differential equations
02.30.Lt Sequences, series, and summability
41.20.Cv Electrostatics; Poisson and Laplace equations, boundary-value problems
41.20.Gz Magnetostatics; magnetic shielding, magnetic induction, boundary-value problems

Impregnated‐electrode‐type liquid metal ion source

Junzo Ishikawa and Toshinori Takagi

J. Appl. Phys. 56, 3050 (1984); http://dx.doi.org/10.1063/1.333886 (7 pages) | Cited 19 times

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An impregnated‐electrode‐type liquid metal ion source has been developed in which a sintered porous tungsten tip is used. The flow rate of the liquid metal can be controlled by selecting the diameters of the tungsten powders to be sintered (10 and 100 μm). Since the liquid metal can be stably supplied to the tip head, stable operation in a wide range from low (a few μA) to high ion current (a few hundred μA) is possible for various metals such as gallium and gold. Moreover, it is also a potential ion source with liquid metals such as silver with high vapor pressure at the melting point. A new method of holding and directly heating the main component of the ion source by means of knife‐edged electrodes with a spring is extremely effective for high temperature operation.
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29.25.Lg Ion sources: polarized
29.25.Ni Ion sources: positive and negative
07.77.-n Atomic, molecular, and charged-particle sources and detectors
52.80.Pi High-frequency and RF discharges

Scattering by lossy dielectric nonspherical objects with nonvanishing magnetic susceptibility

Akhlesh Lakhtakia, Vijay K. Varadan, and Vasundara V. Varadan

J. Appl. Phys. 56, 3057 (1984); http://dx.doi.org/10.1063/1.333887 (4 pages) | Cited 1 time

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Using the recently formulated iterative extended boundary condition method (IEBCM) it is shown that the absorption mechanisms in a lossy dielectric object are enhanced by the presence of a nonvanishing magnetic susceptibility. In addition, there is a corresponding reduction in the backscattering cross section. The conditional convergence of the IEBCM algorithm is also proved.
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42.25.Fx Diffraction and scattering
77.90.+k Other topics in dielectrics, piezoelectrics, and ferroelectrics and their properties (restricted to new topics in section 77)

Wavelength‐modulated reflectivity spectra of MnxCd1−xTe alloys at the Γ and Λ points

B. Montegu, A. Laugier, and R. Triboulet

J. Appl. Phys. 56, 3061 (1984); http://dx.doi.org/10.1063/1.333888 (6 pages) | Cited 11 times

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MnxCd1−xTe alloys are studied by wavelength modulation reflectivity for the composition range 0<x<0.75. Optical transitions around Γ and Λ critical points are investigated from T=10–300 K. In all the composition ranges the nature of the transitions appears to be the same as in CdTe: E0=Γv8−Γc6, E1=Λc6−(Λ4+Λ5)v, E1+Δ1=Λc6−Λv8. The energy position of these structures changes linearly with x.
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78.40.Kc Metals, semimetals, and alloys
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
71.20.Nr Semiconductor compounds
71.20.Ps Other inorganic compounds

Optimum beam thickness for the Raman‐type free‐electron laser using a two‐dimensional hollow beam

T. Shiozawa and T. Nakashima

J. Appl. Phys. 56, 3067 (1984); http://dx.doi.org/10.1063/1.333889 (8 pages) | Cited 2 times

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The effect of an arbitrary beam thickness is investigated for a two‐dimensional Raman‐type free‐electron laser composed of a hollow relativistic electron beam and a parallel plate waveguide containing it. On the basis of the fluid theory for electron beams, analytical expressions are given for the dispersion relation and the spatial growth rate of a scattered wave (even TE mode) and an electron plasma wave (even TM mode) coupled under the influence of a pump wave (even TE mode). Then, from the numerical analysis for an important case where both the pump and scattered waves are the lowest‐order even TE mode, the following interesting results are obtained. First, the hollow beam can propagate two distinct modes of the electron plasma wave with even symmetry characterized by different field distributions. One mode (mode 1) corresponds to the normal mode of the solid beam while the other mode is inherent to the hollow beam. In addition, the growth rate for the mode 1 is considerably larger than that for the mode 2. In particular, the optimum beam thickness is found for which the growth rate for the mode 1 becomes maximum and yet that for the mode 2 is sufficiently small.
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42.55.-f Lasers
41.75.Fr Electron and positron beams

Heavy‐atom effects in laser properties of 9‐acetoxy‐10‐acetoxyhalogenophenylanthracene derivatives

Janina R. Heldt, Jan Szczepański, and Józef Heldt

J. Appl. Phys. 56, 3075 (1984); http://dx.doi.org/10.1063/1.333890 (6 pages) | Cited 4 times

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Laser emission has been found for eight new 9‐acetoxy‐10‐acetoxyhalogenophenylanthracene. For these compounds the absorption threshold power, laser output energy, and lasing region have been determined. It has been found that derivatives possessing –OAc or heavy‐atom substituents in position 2′ or 6′ of the phenyl ring show laser properties differing distinctly from those compounds which have them in positions 4′, 3′ or 5′. These differences can be explained throughout by ‘‘internal heavy‐atom’’ effects and interaction—hydrogen bonding—of the substituted phenyl ring with the anthracene skeleton. This interaction shifts the triplet levels causing a decrease of T1–Tn absorption losses.
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42.55.Mv Dye lasers
33.50.-j Fluorescence and phosphorescence; radiationless transitions, quenching (intersystem crossing, internal conversion)
78.45.+h Stimulated emission

Resolution and definition in photothermal imaging

Grover C. Wetsel and F. Alan McDonald

J. Appl. Phys. 56, 3081 (1984); http://dx.doi.org/10.1063/1.333891 (5 pages) | Cited 6 times

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The influences of pump and probe beam sizes, as well as chopping frequency, on resolution and definition in photothermal laser‐beam‐deflection imaging of subsurface structure are investigated experimentally and theoretically. It is shown that the resolution of nearby subsurface structures is improved by decreasing pump and probe beam sizes to dimensions less than, but not necessarily much less than, the characteristic dimension of the subsurface structures. It is also shown that the photothermal image width (full width at half maximum) may be different from the structure size, and that the width may vary with frequency, for certain structure geometry. A theoretical model of thermal‐wave scattering gives results consistent with the present experimental data and with previous, apparently contradictory, results in the appropriate geometric limits.
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68.35.-p Solid surfaces and solid-solid interfaces: structure and energetics
68.37.-d Microscopy of surfaces, interfaces, and thin films
42.62.-b Laser applications
07.60.-j Optical instruments and equipment

InGaAsP/InGaP buried heterostructure lasers at 810 nm

K. Wakao, S. Isozumi, H. Nishi, and S. Ohsaka

J. Appl. Phys. 56, 3086 (1984); http://dx.doi.org/10.1063/1.333865 (2 pages) | Cited 1 time

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InGaAsP/InGaP buried heterostructure lasers emitting at 810 nm have been grown on GaAs substrates using two‐step liquid‐phase epitaxy. A threshold current of 79 mA and an external differential quantum efficiency of 26% are obtained. Fundamental transverse mode operation up to 3 mW is achieved in the laser with the active region of 3.5 μm wide.
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42.55.Px Semiconductor lasers; laser diodes
42.60.By Design of specific laser systems

Influences of thin active layer in (GaAl)As double‐heterostructure lasers grown by liquid‐phase epitaxy

T. Hayakawa, N. Miyauchi, T. Suyama, S. Yamamoto, H. Hayashi, S. Yano, and T. Hijikata

J. Appl. Phys. 56, 3088 (1984); http://dx.doi.org/10.1063/1.333866 (8 pages) | Cited 5 times

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Studies have been carried out on the influences of thinning the active layer in (GaAl)As double‐heterostructure (DH) lasers grown by liquid‐phase epitaxy (LPE). The measured peak gain varies sublinearly with current in the laser with a thin active layer of d∼0.05 μm while it varies linearly for d≲0.07 μm. This sublinear gain‐current relationship results from the rather wide graded‐band‐gap interface region formed by LPE and increases the lasing threshold. The photoluminescence (PL) peak of a DH sample with a thin active layer shifts to higher energies with the excitation due to the wide interface width, which agrees with the calculated results. High‐energy bumps observed in the PL spectra are more noticeable in the sample with the thinner active layer, which demonstrates that carriers recombine at the high‐energy portion of the interface region. The excitation dependence of PL intensity has shown that the nonradiative recombination rate is higher for the thinner active layer. Discussion is given concerning the causes for the rapid degradation of the lasers with the active layer thinner than a certain value.
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42.55.Px Semiconductor lasers; laser diodes
78.40.Fy Semiconductors
73.40.Lq Other semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
78.45.+h Stimulated emission

Technique for measurement of the gain spectra of semiconductor diode lasers

Daniel T. Cassidy

J. Appl. Phys. 56, 3096 (1984); http://dx.doi.org/10.1063/1.333867 (4 pages) | Cited 63 times

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A simple technique for determining the gain spectra of semiconductor lasers from measurements of the emission spectra of the laser is presented. The technique is insensitive to the response function of the device used to determine the emission spectra of the laser. Accurate estimates of the gain can be obtained from data which have been convolved with an instrument response function of ≲0.5 Å FWHM for a cavity free spectral range of 2.5 Å. Two applications of the gain data obtained by the technique are presented.
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42.55.Px Semiconductor lasers; laser diodes
42.60.Jf Beam characteristics: profile, intensity, and power; spatial pattern formation

Fast‐Fourier‐transform based beam‐propagation model for stripe‐geometry semiconductor lasers: Inclusion of axial effects

Govind P. Agrawal

J. Appl. Phys. 56, 3100 (1984); http://dx.doi.org/10.1063/1.333868 (10 pages) | Cited 56 times

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The static characteristics of gain‐guided double‐heterostructure semiconductor lasers are modeled using a beam‐propagation method that is capable of including both the axial and lateral variations of the optical‐mode and carrier‐density profiles. The use of the fast‐Fourier‐transform algorithm for the lateral mode propagation results in a relatively fast numerical procedure to obtain the self‐consistent solution of the wave equation coupled to a nonlinear carrier‐diffusion equation. To compare it with previous work, the model is applied to study the above‐threshold behavior of an axially uniform AlGaAs laser. The inclusion of axial effects leads to minor (∼few percent) quantitative changes. As a novel application of the beam‐propagation model, a tapered‐stripe AlGaAs laser is analyzed in detail. In this axially nonuniform device the lateral profiles for the carrier density and the forward and backward waves exhibit considerable axial variations and affect the behavior both qualitatively and quantitatively. The calculated results are in reasonable agreement with the reported experimental observations.
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42.55.Px Semiconductor lasers; laser diodes
42.60.Da Resonators, cavities, amplifiers, arrays, and rings
42.60.Jf Beam characteristics: profile, intensity, and power; spatial pattern formation

Generalized rate equations and modulation characteristics of external‐cavity semiconductor lasers

Govind P. Agrawal

J. Appl. Phys. 56, 3110 (1984); http://dx.doi.org/10.1063/1.333869 (6 pages) | Cited 7 times

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Modulation characteristics such as the power response and the dynamic frequency shift (chirp) of an external‐cavity semiconductor laser are analyzed using a set of generalized rate equations for a single longitudinal mode selected by the coupled‐cavity device. The general formalism is applied to the specific case where the external cavity consists of a rod of graded‐index material (GRINROD cavity). Particular attention is paid to the chirp reduction and its optimization in the presence of intercavity coupling. The results are in reasonable agreement with the recent experimental observations.
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42.55.Px Semiconductor lasers; laser diodes
42.60.Fc Modulation, tuning, and mode locking
42.60.Da Resonators, cavities, amplifiers, arrays, and rings

Analysis of astigmatism of gain guided laser with a tapered‐stripe geometry

Takayoshi Mamine, Tatsuji Oda, and Osamu Yoneyama

J. Appl. Phys. 56, 3116 (1984); http://dx.doi.org/10.1063/1.333870 (5 pages) | Cited 1 time

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The astigmatism of the tapered‐stripe (TAPS) laser has been analyzed. Calculating the near‐field spot size and the radius of curvature in the tapered‐stripe region, the astigmatism is determined by using the expression of D=Re [1+(λRe/ πw2e)2]−1. In our formalism we assume that the gain profile is parabola and the near‐field spot size at the facet is determined by the diffusion length of injected carriers. So far as these assumptions are valid, it is concluded that the amount of astigmatism is reduced with the length of tapered stripe, using the refractive index change due to the band‐edge absorption of −10−2. The fundamental characteristics of the gain guided laser with TAPS structure such as the astigmatism, far‐field radiation pattern, and the spontaneous emission factor are shown to be controlled by properly designing the stripe geometry and the thickness of the active layer.
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42.55.Px Semiconductor lasers; laser diodes
42.62.-b Laser applications
42.60.Jf Beam characteristics: profile, intensity, and power; spatial pattern formation
42.15.Dp Wave fronts and ray tracing

Thermodynamic limits to nonlinearity. II. Purely‐resistive, dissipative systems

Madhu S. Gupta

J. Appl. Phys. 56, 3121 (1984); http://dx.doi.org/10.1063/1.333871 (6 pages)

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This paper deals with the nonlinearity of a class of idealized thermodynamic systems, such as electrical resistors and semiconductor junction diodes, in which energy is dissipated when the flow of an extensive quantity takes place through them, and the extensive variable is not stored in the system. A thermodynamic model of such a system is constructed by representing it as a weak coupling between two storage systems described by a Master equation. The lowest‐order dimensionless measure of nonlinearity, defined as the second derivative of the force variable with respect to the flow, normalized with respect to the flow and the first derivative, is shown to have a lower bound of −2. The proof is based on the assumptions that the force and flow variables are functionally related, and the system is homogeneous, stable, and has a single flow in it.
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05.70.-a Thermodynamics
85.30.Kk Junction diodes
84.32.Ff Conductors, resistors (including thermistors, varistors, and photoresistors)
72.20.Ht High-field and nonlinear effects

Conductivity and permeability from microgeometry

J. Koplik, C. Lin, and M. Vermette

J. Appl. Phys. 56, 3127 (1984); http://dx.doi.org/10.1063/1.333872 (5 pages) | Cited 59 times

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We show how the electrical conductivity and the fluid flow permeability of a disordered random medium may be calculated from the microscopic geometry of the pore space. Serial sections of the pore space are used to determine an equivalent random network of cylinders, the transport coefficients of this network are related to the conductivity of an analog random resistor network, and the latter is calculated using an effective medium approximation. The procedure is illustrated by detailed analysis of a Massilon sandstone.
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47.56.+r Flows through porous media
91.60.Pn Magnetic and electrical properties
91.60.Ba Elasticity, fracture, and flow
72.90.+y Other topics in electronic transport in condensed matter (restricted to new topics in section 72)

Effects of a cold electron beam on the parametric decay of a Langmuir wave

Joseph E. Willett and Yildirim Aktas

J. Appl. Phys. 56, 3132 (1984); http://dx.doi.org/10.1063/1.333873 (5 pages) | Cited 2 times

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A formalism for the parametric decay of a Langmuir wave into a backscattered Langmuir wave and an electrostatic ion wave in an electron beam‐plasma system is developed. Explicit growth rates and dispersion relations for the ion wave modified by mode coupling and a nearly monoenergetic electron beam are derived. A numerical study of the effects of the beam on the growth rate for this resonant backscatter decay instability is presented.
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52.40.Mj Particle beam interactions in plasmas
52.35.Fp Electrostatic waves and oscillations (e.g., ion-acoustic waves)
52.35.Py Macroinstabilities (hydromagnetic, e.g., kink, fire-hose, mirror, ballooning, tearing, trapped-particle, flute, Rayleigh-Taylor, etc.)

Planar‐type self‐magnetically‐insulated diode as a new source of intense pulsed light‐ion beam

T. Yoshikawa, K. Masugata, M. Ito, M. Matsui, and K. Yatsui

J. Appl. Phys. 56, 3137 (1984); http://dx.doi.org/10.1063/1.333874 (4 pages) | Cited 1 time

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A new type of ion diode named the ‘‘Planar‐Type Self‐Magnetically‐Insulated Diode’’ is developed. Good efficiency of ion production (∼30%) is obtained with good reproducibility. A multiple‐shot operation (40 shots or even more) is possible with relatively high power (900 kV, 180 kA). Surface flashover of the anode is affected by an initial irradiation of lower‐energy electrons of the incident voltage pulse.
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29.25.Lg Ion sources: polarized
29.25.Ni Ion sources: positive and negative
41.75.Ak Positive-ion beams
41.75.Cn Negative-ion beams
84.70.+p High-current and high-voltage technology: power systems; power transmission lines and cables
52.50.Dg Plasma sources

A hollow cathode arc in neon: Simultaneous laser probing and molecular‐beam sampling of metastable atoms as a plasma diagnostic

M. J. Verheijen, H. C. W. Beijerinck, P. W. E. Berkers, D. C. Schram, and N. F. Verster

J. Appl. Phys. 56, 3141 (1984); http://dx.doi.org/10.1063/1.333875 (10 pages) | Cited 2 times

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The mean free path of metastable rare‐gas atoms in a plasma can be determined by simultaneous sampling of a beam of metastable atoms through an orifice in the wall and optically pumping of the metastable atoms in the plasma with a cw dye laser beam perpendicular to the atomic beam axis. This method gives very accurate results for the absolute value and the velocity dependence (using a time‐of‐flight detection technique) of this mean free path. With a simple model the contributions of collisions with electrons and with heavy particles to the experimental mean free path can be determined from the velocity dependence. We have applied this method to the external plasma column of a hollow cathode arc in neon. The experimentally determined mean free path of 2–10 mm points unambiguously to a surprisingly low degree of ionization of 2% or less. At these conditions the plasma column is fully transparent for the background atoms in the vacuum chamber. This all means that the character of the plasma of a hollow cathode arc in neon is totally different from argon and helium, which is probably caused by the isotope composition of neon.
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52.70.Kz Optical (ultraviolet, visible, infrared) measurements
52.20.Fs Electron collisions
52.25.Fi Transport properties
52.20.Hv Atomic, molecular, ion, and heavy-particle collisions

Ozone formation behind pulsed‐laser‐generated blast waves in oxygen

J. Stricker and J. G. Parker

J. Appl. Phys. 56, 3151 (1984); http://dx.doi.org/10.1063/1.333876 (12 pages) | Cited 1 time

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The formation of ozone behind blast waves in oxygen generated by a pulsed laser has been investigated both experimentally and theoretically, over cell pressure range of 0.68–27 atm. Ozone buildup formed by successive pulses was monitored by recording UV absorption at 2540 Å. It was found that, as the number of pulses increase, the rate of ozone formation decreased until finally an equilibrium concentration was reached. This equilibrium magnitude was determined by the condition that the number of ozone molecules produced by the wave equals the number decomposed by the same wave. The decomposition and formation of O3 during a single pulse were monitored by time‐resolved UV absorption measurements. In order to provide a fundamental basis for interpretation of the mechanism of ozone formation, a mathematical model was developed. Although qualitatively measurements and theory agree, the data, mainly on the number of O3 molecules produced per pulse, is in significant disagreement. Several possible explanations of this discrepancy are given.
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82.40.Fp Shock wave initiated reactions, high-pressure chemistry
82.30.Lp Decomposition reactions (pyrolysis, dissociation, and fragmentation)
82.50.-m Photochemistry
47.70.Fw Chemically reactive flows

A new type of corona‐discharge photoionization source for gas lasers

R. Marchetti, E. Penco, and G. Salvetti

J. Appl. Phys. 56, 3163 (1984); http://dx.doi.org/10.1063/1.333877 (6 pages) | Cited 10 times

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We present results of an experimental study aimed at characterizing a new type of corona‐discharge photon source, which is particularly suitable to be used as preionizer in transversely excited gas lasers operating at high pulse repetition frequencies. Results of comparative tests carried out in CO2 laser gas mixtures between this photoionization source and a conventional bare spark source are also reported, showing the superiority of the proposed scheme.
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42.55.Lt Gas lasers including excimer and metal-vapor lasers
51.50.+v Electrical properties (ionization, breakdown, electron and ion mobility, etc.)
33.80.Eh Autoionization, photoionization, and photodetachment
52.80.Hc Glow; corona

Shortening of electron conduction pulses by electron attachers O2, N2O, and CF4

L. C. Lee and F. Li

J. Appl. Phys. 56, 3169 (1984); http://dx.doi.org/10.1063/1.333878 (6 pages) | Cited 15 times

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A uniform electron density is produced by two‐photon ionization of trace trimethylamine in the N2 buffer gas of atmospheric pressure using ArF laser photons. The transient conduction pulses induced by the electron motion between parallel electrodes under various applied electric fields are observed. The duration of the electron transient pulse is shortened when the electron attacher O2, N2O, or CF4 is added to the buffer gas. Electron attachment rate constants are obtained from the ratios of the transient current with and without attachers at various times after the laser pulses. For O2 and N2O, the electron attachment rate constants measured in this experiment agree with previous values measured by different methods. The apparent rate constants for the attachment of low‐energy electrons by CF4 are measured. The electron drift velocity is found to increase when CF4 is added to N2. The present method is applicable for the measurement of the electron attachment rate associated with the production of short‐lived negative ions.
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52.20.Fs Electron collisions
51.50.+v Electrical properties (ionization, breakdown, electron and ion mobility, etc.)
52.25.Fi Transport properties
52.80.Dy Low-field and Townsend discharges

Gradient B drift transport of high current electron beams

James R. Lee, Robert C. Backstrom, John A. Halbleib, Jeffrey P. Quintenz, and Thomas P. Wright

J. Appl. Phys. 56, 3175 (1984); http://dx.doi.org/10.1063/1.333879 (7 pages) | Cited 6 times

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A 1‐MeV, 200‐kA electron beam was transported 89 cm in a low pressure background gas via gradient B drift in the 1/r azimuthal magnetic field of a current carrying wire. The electron drift velocity was measured and found to be in good agreement with theory. Measurements of x‐ray production in the target indicated high transport efficiency.
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41.75.Fr Electron and positron beams
84.70.+p High-current and high-voltage technology: power systems; power transmission lines and cables
52.40.Mj Particle beam interactions in plasmas

Momentum equation for arc‐driven rail guns

Jad H. Batteh

J. Appl. Phys. 56, 3182 (1984); http://dx.doi.org/10.1063/1.333880 (5 pages) | Cited 6 times

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In several models of arc‐driven rail guns, the rails are assumed to be infinitely high to simplify the calculation of the electromagnetic fields which appear in the momentum equation for the arc. This assumption leads to overestimates of the arc pressures and accelerations by approximately a factor of 2 for typical rail‐gun geometries. In this paper, we develop a simple method for modifying the momentum equation to account for the effect of finite‐height rails on the performance of the rail gun and the properties of the arc. The modification is based on an integration of the Lorentz force across the arc cross section at each axial location in the arc. Application of this technique suggests that, for typical rail‐gun geometries and moderately long arcs, the momentum equation appropriate for infinite‐height rails can be retained provided that the magnetic pressure term in the equation is scaled by a factor which depends on the effective inductance of the gun. The analysis also indicates that the magnetic pressure gradient actually changes sign near the arc/projectile boundary because of the magnetic fields associated with the arc current.
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52.75.Di Ion and plasma propulsion
52.80.Mg Arcs; sparks; lightning; atmospheric electricity

Stress profiles in rail‐gun projectiles with distributed armatures

Jad H. Batteh

J. Appl. Phys. 56, 3187 (1984); http://dx.doi.org/10.1063/1.333881 (4 pages) | Cited 1 time

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The one‐dimensional steady‐state momentum equation for rail guns is used to develop an analytic model for the acceleration stresses which arise in rail‐gun projectiles. The model is applicable to the case where several armatures are embedded throughout the projectile and provides an expression for the stress as a function of integrals of the electrical conductivity and density distributions in the projectile. This expression is used to derive the conductivity profile which minimizes the stress in the projectile. Stress profiles are calculated for several distributed armature designs. The investigation indicates that, for both solid and arc armatures, the peak stress in a projectile with N uniformly distributed, discrete armatures is proportional to 1/N.
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52.75.Di Ion and plasma propulsion
52.80.Mg Arcs; sparks; lightning; atmospheric electricity
84.90.+a Other topics in electronics, radiowave and microwave technology, and direct energy conversion and storage (restricted to new topics in section 84)
84.70.+p High-current and high-voltage technology: power systems; power transmission lines and cables

Investigation of the striking characteristics of a Penning ion source

Felix K. Chen

J. Appl. Phys. 56, 3191 (1984); http://dx.doi.org/10.1063/1.333882 (7 pages) | Cited 2 times

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This work describes a new technique which uses the time spectrum of fast neutrons produced by the extracted ions to study the switching characteristics of a small Penning ion source. It is found that the rise and delay times of the Penning discharge decrease with the pressure and the anode voltage, and are insensitive to the magnetic field provided that the electron confinement time is much longer than the mean ionization time. A proposed model successfully explains the rise‐time variations with the source operating parameters.
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52.80.Sm Magnetoactive discharges (e.g., Penning discharges)
07.77.-n Atomic, molecular, and charged-particle sources and detectors
29.25.Lg Ion sources: polarized
29.25.Ni Ion sources: positive and negative
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