Electric Inhomogeneity Research Articles

Measurement of Magnetic and Electric Field Inhomogeneities in a Time Projection Chamber Using Laser Tracks

In a model time projection chamber with a drift length of 1.3 m we study the track distortions caused by inhomogeneous or misaligned fields. The measured coordinate displacements are used to calculate the integrals over the transverse field components; these are found to be in agreement with the independently measured magnetic field.

Effect of charge carrier collection on the shape of the amplitude spectrum of coaxial Ge(Li) detectors

The paper presents a study of the effect of charge collection on the shape of the full energy peak for true coaxial Ge(Li)-detectors, homogeneous with respect to their electrophysical parameters.Calculations of amplitude spectra were carried out for a detector of 2.8 cm height, with 3.6 cm diameter, and with 0.6 cm diameter for the p+-region. The transport of gamma radiation was simulated by means of a Monte Carlo method, and the process of charge collection was treated analytically.It is shown that resolution depends essentially on the rate of change of the collection efficiency in the region of the detector in which the greater part of the energy of a gamma photon is absorbed. As a result of electric field inhomogeneity, trapping of holes affects the magnitude of collected charge (and, accordingly, the shape of the amplitude spectrum) to a greater extent than trapping of electrons. Strong trapping of electrons leads to the formation of a “tail” in the small amplitude region, the peak, as a rule remaining well pronounced and resolution not deteriorating very much. Strong hole trapping usually leads to distortion of the peak shape and to deterioration of the resolution.Multiple scattering of gamma rays improves resolution under conditions of predominant hole trapping and deteriorates it if electron trapping dominates. Dependence of resolution on the electron trapping length at various hole trapping lengths are presented for a detector possessing the geometric dimensions quoted above.

Dependence of ion cyclotron frequency on electric field inhomogeneity

A quantum mechanical treatment of classically behaving ion motion in an ICR drift cell is given. For this description the coherent state wave function, as wave packet, minimized according to the uncertainty principle has been applied. The electric field inhomogeneity effect upon the cyclotron frequency is determined with the Schrödinger perturbation theory. The theoretical results are compared with experimental determinations of the dependence of the cyclotron frequency on the magnetic field and found to be in good agreement. They can be utilized for calibration of the mass scale.

Electric-field-induced changes in spin-lattice relaxation in polar liquids

Spin—lattice relaxation times of acetonitrile, aligned by an electric field, have been measured. In contrast to earlier investigations on other polar liquids, no electric-field effects on T 1 could be established. The apparent discrepancy is discussed in terms of electric conduction and inhomogeneity of the applied electric field.

Two-frequency 100-line addressing of a reflective twisted-nematic liquid-crystal matrix display

Scanning of more than 100 lines of a reflective twisted-nematic liquid-crystal matrix display with full contrast can be achieved using a two-frequency addressing scheme and a liquid crystal showing a dielectric anisotropy that is positive for low frequencies and negative for high frequencies. It is shown that the electric field inhomogeneity, caused by the large dielectric constants, changes the optical response to low and high frequencies as well as the angular dependence of the optical transmission.

Electroreflectance Spectra of Heavily Doped Semiconductors. Field Inhomogeneity in the Low‐Field Limit

AbstractThe influence of the electric field inhomogeneity on the electrorefleetance (ER) spectra has been included into the theory in the low‐field limit by means of the corrected Seraphin coefficients. One typical example of the ER spectra of heavily doped Ge (n‐type samples with donor concentration ND = 9 × 1017 cm−8) in the range of E1 and E1 + Δ1 transitions proves that the lineshape of the ER spectra may well be expressed by the microscopic model verified earlier for pure Ge with additional inclusion of the field inhomogeneity.

High−vacuum trapping experiments on the astron

Experimental results of high−vacuum (10−7 to 10−6 Torr) E−layer trapping experiments on the astron are presented. Both single and multiple pulse experiments are reported. The precessional mode is stabilized with a toroidal field. At sufficiently low pressures (≲5×10−6 Torr), E layers were observed to be stable for up to 200 msec. For greater times, the applied toroidal field had decayed sufficiently so that the layer was unstable to precessions. Axial compression of the layer was observed as it was neutralized by ionization of the background gas. Compressions by a factor of two were observed. For layers whose self−well is the dominant focusing force, this compression agrees with adiabatic theory. A small (≈20%) E−layer loss was observed during the compression. It is felt that this loss arises from scattering in electric field inhomogeneities. The effect of resistive walls on trapping efficiency was studied and it was shown that the efficiency scales with the theoretically calculated energy loss in the resistive walls. Finally, the results of the multiple pulse experiments are presented. Failure to achieve buildup of the E layer is attributed to a combination of losses during compression and poor trapping efficiency on later pulses.

Measurement of the dipole moment of CF 3CN

The Stark effect was observed for K = 0 and K = 1, J = 1 → 2 transitions in CF 3CN. Measurements were made in a Stark modulated microwave spectrometer. The dipole moment obtained was μ = 1.262 ± 0.010 D. An analysis of the effects of electric field inhomogeneities on the observed Stark shifts for K = 0 and K = 1 states is included. Appropriate corrections are given for measuring linear Stark effects in a standard waveguide cell calibrated using a molecule with second-order Stark effect.

Ionospheric electric field and current distribution associated with high altitude electric field inhomogeneities

A quantitative theoretical analysis of electric field and current distributions in the ionosphere is given assuming certain time variable convection field profiles at an altitude of 1250 km. A number of idealized assumptions regarding the ionospheric characteristics are defined and discussed. A qualitative discussion of a quasi-stationary configuration with an approximately curl free electric field is also given. Geomagnetically field aligned current densities i ∥ of the order 10 −5−10 −4 A m 2 are consistent with quite reasonable assumptions about the convection field E ⊥. Oscillations in E ⊥ with periods of the order of 10 sec should readily be generated when σ ∥ is large. In the quasi-stationary case there may be a mechanism that strengthens and concentrates i ∥ locally under certain conditions. It is found that a number of recent high altitude observations of convection field reversals may be consistent with large potential drops along the magnetic field lines. The solutions obtained as well as some of the basic assumptions are compared with observations.

Stabilized Numerical Analytic Prolongation with Poles

Stabilized Numerical Analytic Prolongation with Poles

A theoretical analysis of intracavitary blood mass influence on the heart-lead relationship.

As a result of theoretic advances made during the past 10 years, it is now feasible to record scalar and vector electrocardiograms in a manner which is independent of body shape and cardiac location. A similar independence of the body's electric inhomogeneities has not yet been achieved. On the contrary, the evidence presented here shows that inhomogeneity phases in the body, especially the intracavitary blood mass, exert a powerful influence on the heart-lead relationship. The particular effect of the intracavitary phase is to augment the manifest strength of normal components of myocardial doublets, and to reduce the manifest strength of tangential components. This augmentation-reduction effect is quantitatively predictable under conditions of simple idealization, and has been confirmed by experiments on electrocardiograpic models. The net effect of the intracavitary phase is probably to produce quasi-vectorial registration of the electromotive forces of the heart, at least during the normal depolarization phase.