摘要:

An electrochemical meter designed for measurements in the marine environment but equally useful in other natural environments is described. Some features of the instrument are (1) all input channels are high impedance; (2) up to 11 reading electrodes can be monitored from one reference electrode; (3) voltages are measured with respect to solution ground; (4) a null balance circuit option; (5) an accuracy of better than 1 mV. With suitable operative ion‐selective electrodes, the instrument can monitor (a) operational activities, (b) activity ratios, (c) solubility products, or (d) states of saturation.

ISSN:0034-6748    

DOI:10.1063/1.1684516

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

The theory for a radiation meter with freedom from necessity for convection cooling correction is developed, and a parameter, the ``mean radiation temperature,'' is defined. An experimental demonstration of the use of the meter is described and discussed. Examples of applications are given.

ISSN:0034-6748    

DOI:10.1063/1.1684517

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

A crossed electric and magnetic field analyzer has been developed to select ions of a givenmi/qratio and record their velocity distribution. The initial velocities of the ions are mainly directed along the magnetic field of the analyzer; the detection is performed in a plane perpendicular to it. The ion optical properties of the analyzing structure and its sensitivity to space charge effects are illustrated by the synoptical recordings of the velocity distributions of protons leaving a conical theta pinch plasma accelerator. The velocity spectrogram appeared on an ion sensitive plate positioned in the detection plane, showing a series of well focused images of the inlet. In some cases, the particle density in the proton beam could be deduced from the features of the spectrogram.

ISSN:0034-6748    

DOI:10.1063/1.1684518

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

A fast acting, all‐metal valve has been developed for injecting pulses of neutral gases into a high vacuum. The theoretical motion of the piston is analyzed and compared with its actual dynamic and electrical operating characteristics. The design of the valve makes it possible to change the length of time the valve is open and thus vary the number of atoms admitted. Preliminary measurements of the pressure in the gas pulses have been made with fast stabilized ionization gauges. Reproducibility of measurement of the operating times of valve and gas pressure pulses was better than 95%. The gases used were hydrogen, helium, argon, and nitrogen.

ISSN:0034-6748    

DOI:10.1063/1.1684519

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

Formulas are given for the plasma density and velocity required to simulate the flow of the solar wind over the magnetosphere of the earth. A description of a plasma source (coaxial arc‐jet) intended to produce appropriate plasma flows is given. The operation of the device is described. Preliminary measurements of the density and velocity, made with a bolometer and a ballistic pendulum, indicate that plasma densities of 1013/cm3and velocities of 107cm/sec have been achieved in a jet of 1 m diameter. These parameters have been verified by microwave and Langmuir probe measurements and are appropriate for the desired simulation. In addition, it has been shown for the first time that this plasma has the required percentage ionization for solar wind simulation.

ISSN:0034-6748    

DOI:10.1063/1.1684520

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

A novel dual‐disk chopper for time‐of‐flight (TOF) measurements is described. Analytical expressions relating the dual‐disk TOF signals to the density and the pertinent parameters of the speed distribution function of a molecular beam are presented. It is demonstrated that use of this new chopper simplifies greatly the experimental and data reduction procedures by obviating, for the determination of most molecular beam parameters, the need for information concerning the gate function of the chopper, the dynamic function of the detector and its electronics, and the absolute zero‐time reference point.

ISSN:0034-6748    

DOI:10.1063/1.1684521

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

The design and error analysis of a high accuracy, high sensitivity, low interaction tension‐torsion extensometer for use on thin wall tubes is presented. Direct current differential transformers are used as position transducers and the extensometer outputs are independent of any symmetric specimen bending that may occur, although it is possible to combine the outputs to measure bending in two perpendicular directions through the specimen axis in order to check specimen alignment. Usable accuracies are of the order of 10−4% for both modes, the interaction of the two modes is less than 0.2%, and over‐all linearity is better than 0.5%, all percentages being relative to full scale. The total strain range is 5% in tension and 1.25% in torsion.

ISSN:0034-6748    

DOI:10.1063/1.1684522

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

An electron diffraction unit using counting techniques has been built which makes it possible to record relative total (elastic and inelastic) differential scattering cross sections directly. Features of the unit which deviate from those in conventional units (which incorporate a rotating sector and photographic plates) are described in detail. The possible uses and limitations of the new instrument are discussed. The total scattered intensities in the range 1.5≤s(Å−1)≤7.2 with 40 keV electrons from N2O and CO2are presented as examples. The results are compared to the predictions of the independent atom model and differences due to chemical binding and electronic correlation effects are observed.

ISSN:0034-6748    

DOI:10.1063/1.1684523

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

A wheel which is mounted in a carriage is held in nonsliding contact with the surface of a cylinder. Both translation of the carriage parallel to the cylinder and the angle that the plane of the wheel makes with the axis are coupled mechanically with the motion of a stylus. Tracing the boundary of a closed figure of arbitrary shape causes the cylinder to rotate. It is shown that the total rotation is directly proportional to the enclosed area. Details of construction and some estimates of accuracy are also given.

ISSN:0034-6748    

DOI:10.1063/1.1684524

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

The use of ``phase modulated'' synchronized electronic oscillators is discussed in considerable detail, including the theoretical background as well as practical circuitry for measuring minor reactance changes (capacitance as low as 0.00004 pF or correspondingly low inductance). The proposed circuitry has some definite advantages over certain other schemes and has been used for some time in seismographic and other instrument design where remote sensing, taking advantage of reactance changes, is employed.

ISSN:0034-6748    

DOI:10.1063/1.1684525

出版商:AIP    

年代:1970

数据来源: AIP