摘要:

The construction and operation of a Connes‐type Fourier spectrometer are discussed in an astronomical context with a sample of the type of spectra obtained with the system.

ISSN:0034-6748    

DOI:10.1063/1.1684890

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

An electron bombardment ionizer for accelerated molecular beams is described which utilizes the electron space charge potential well to suppress ions formed from molecules with thermal energies. Ions produced from molecular beams that have been aerodynamically accelerated in seeded supersonic jets to kinetic energies above 2 eV have been separated from ions formed from the propellant light molecules and background gas. The efficiency of the ionizer is approximately a factor of 10 lower than that of conventional high efficiency electron bombardment ionizers.

ISSN:0034-6748    

DOI:10.1063/1.1684891

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

A vacuum tight crucible has been constructed for use in growing metal single crystals. This crucible design can be used for growing metal single crystals of reactive, volatile, or toxic materials by a Bridgeman technique.

ISSN:0034-6748    

DOI:10.1063/1.1684892

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

A mechanical ``symmetrizer'' has been built for use with far infrared interferometers driven by stepping motors. It allows convenient and consistent setting of the position of zero phase difference and thereby permits straightforward Fourier analysis of the measured one‐sided (even) interferogram.

ISSN:0034-6748    

DOI:10.1063/1.1684893

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

The factors which determine the minimum magnetic field inside a set of cylindrical shields of high permeability material are summarized. Using this information a three cylinder system was designed and constructed to screen out the earth's magnetic field inside the Dewar of a dilution refrigerator to less than 5×10−5Oe.

ISSN:0034-6748    

DOI:10.1063/1.1684894

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

An oscilloscope display is described that can be used for signal‐to‐noise enhancement, presentation of spectral data in compact form, and X‐Y data plotting. The display also functions as an optical signal averager and is useful in the detection of signals whose frequencies are not knowna prioriand signals whose frequencies drift in time. Results obtained in simulation tests and in experimental research on plasma waves and instabilities are described.

ISSN:0034-6748    

DOI:10.1063/1.1684895

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

A reflectometer has been built for measuring the reflectance of liquids in the vacuum ultraviolet. A monochromator is rotated about a liquid sample in equilibrium with its vapor in a windowless dish. A continuous range of angles of incidence is provided between 15 and 70°. The light traverses a path of approximately 1 cm in length in the vapor adjacent to the sample. The reflected beam is collected by a light pipe. A description of the mechanisms for positioning the light pipe, adjusting the sample dish, and rotating the monochromator with respect to the reflecting surface is given, as well as the system used to maintain a pressure differential between the monochromator and chamber containing the liquid sample.

ISSN:0034-6748    

DOI:10.1063/1.1684896

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

The use of an electrostatic analyzer as a time‐of‐flight spectrometer for studying laser produced plasmas is discussed. It is shown that a plane electrostatic analyzer, accommodating several detectors simultaneously, can be used to determine several points on the velocity distribution curve for the ions produced upon irradiation of a target with a single Q‐switched laser pulse. This minimizes the problem of shot‐to‐shot reproducibility of the laser. It is shown also that with a 30° plane analyzer good energy and time resolution are obtainable in determining the time dependent ion velocity distribution for a laser produced plasma.

ISSN:0034-6748    

DOI:10.1063/1.1684897

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

The east‐west variations of the earth's magnetic field over the working volume of the NBS precision solenoid are being canceled out by a closed loop system featuring a field controlled rubidium oscillator. The rubidium oscillator and solenoid are sufficiently separated in distance and do not affect each other's operation. Each system is enclosed in three‐dimensional Helmholtz coils. Vertical and north‐south components of earth's field are canceled. An east‐west bias field is provided for rubidium oscillator operation at 10 kHz. The output of a phase sensitive detector locked to the 10 kHz frequency standard provides current for the electrically series connected east‐west Helmholtz coils at both locations. The magnitude of this current is proportional to the phase difference of oscillator and reference. The full range of compensation is 100 nT. The rate of compensation is limited by a time constant of 0.002 sec, an adequate rate for most disturbances. To the extent that the two separated components of the closed loop system can be oriented directionally the same at any given time, the earth's field east‐west variation is compensated exactly.

ISSN:0034-6748    

DOI:10.1063/1.1684898

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

Differential pumping may be made more efficient by application of modified collimators of the grid type, first used for optical collimation only in spectrometers for the extreme uv spectral region. Compared with conventional types of differential pumping, either larger windows can be used, or the gas flow can be reduced. For optical purposes we had to build up a system with a rather large window, with an effective area of 15 mm2. The differential pumping properties of this system are compared to those of a conventional pumping system with an effective area of 3 mm2and the results clearly show the advantage of the new design.

ISSN:0034-6748    

DOI:10.1063/1.1684899

出版商:AIP    

年代:1971

数据来源: AIP