摘要:

A new type of heat transfer gauge that operates in the presence of highly ionized plasmas and in strong electric and magnetic fields has been developed. The principle of its operation is to use a thin opaque surface as the heat transfer element. Aerodynamic and radiative heating is applied to one side of this layer, while measurements are made of the change of the infrared emission from the other side. This system is essentially a bolometer. Since the gauge is initially at room temperature, the predominant radiation from the opaque layer is in the infrared band from 5 to 30 &mgr;. Changes in the temperature of the element are determined by the variation in its infrared emission. The opaque layer is made thin enough so that the temperature of the front surface can be determined in less than 0.1 &mgr;sec. This paper describes the components of the heat transfer system and the methods for calibrating the gauge for heating pulses of long and short duration. Gauge calibrations by heat pulses from shock heated air are presented, and the response time of the gauge to short heat pulses is evaluated.

ISSN:0034-6748    

DOI:10.1063/1.1718042

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

A high‐speed, high‐reliability, automatic diffractometer based on equi‐inclination geometry is described. Precomputed instructions are supplied on punched paper tape. The Miller indices of each reflection are recorded, both counter and initial crystal angles are set and recorded, the diffracted intensities at the required angular intervals in a fixed counter‐moving crystal stepwise scan are measured, and the final crystal angle is recorded automatically, all on punched paper tape. Angles are set to 0.01°. The output tape is processed to give the resulting corrected structure amplitudes on a common scale.

ISSN:0034-6748    

DOI:10.1063/1.1718043

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

A rotary multiple‐filament turret is described which permits sequential vapor deposition of several materials from the same position within a vacuum chamber, thereby eliminating angle‐of‐incidence problems at the receiving surface of the substrate. No dynamic feed‐throughs are used in the system, and only one high‐current feed‐through is used, thus minimizing high‐vacuum leaks.

ISSN:0034-6748    

DOI:10.1063/1.1718044

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

An analysis is given of a direct‐reading system for micron range differential‐capacity type diaphragm manometers. It is shown that electrostatic compensation of diaphragm displacement by feedback produces a linear pressure calibration when control system gain is sufficient. It is also shown that adjustment can be provided for unavoidable inequalities in the manometer capacities without changing the calibration. An experimental direct‐reading gauge is described with deviations from linearity less than 1% in the pressure range 0 to 500 &mgr;.

ISSN:0034-6748    

DOI:10.1063/1.1718045

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

For some plasma experiments high purity hydrogen or deuterium at pressures of 10−3Torr or less is required. It is shown that a molecular pump can be used as a combination pumping, gas injection, and gas purification system. The gas is admitted to the fore vacuum side and streams back to the high vacuum side. This does not materially affect the pumping of heavy impurities. Performance data for this mode of operation are given for the Pfeiffer pump TVP‐500.

ISSN:0034-6748    

DOI:10.1063/1.1718046

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

The transmission vs surface density (thickness) relationship has been determined for thin antimony films. Data are given for both white and monochromatic light (4500, 5380, and 6650 Å). The results are more accurate than those usually tabulated since the surface densities were determined directly from these films. These films were primarily evaporated from evenly coated thin nickel rings, giving films of extreme uniformity. Holland's surface density distribution for films from ring evaporators was found to give an accurate representation of these films. Films of the largest area of constant thickness were produced when the ratio of the evaporation distance to the ring's inner radius was approximately 1.3.

ISSN:0034-6748    

DOI:10.1063/1.1718047

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

A rapid method for obtaining the Seebeck coefficient is described. A Seebeck voltage obtained across a sample with respect to one material of a thermocouple is plotted against that obtained across the sample with respect to the second thermocouple material on an X‐Y recorder as the temperature gradient across the sample is slowly varied. The slope of this curve, which is not dependent upon accurately matched thermocouples, yields the Seebeck coefficient of the sample. This slope can be measured at a point corresponding to zero &Dgr;T.

ISSN:0034-6748    

DOI:10.1063/1.1718048

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

The theory and practical behavior of P+−&pgr;−N+semiconductor photodiodes are given. It is shown that under operating conditions response may be anticipated for light modulated at frequencies in excess of 1010cps. The signal‐to‐noise ratio of such a diode is discussed both for simple detection of amplitude‐modulated light and for the case of optical heterodyne detection. In the latter case a favorable comparison is found with a photomultiplier tube detector. A description of the structure and fabrication of a germanium device is given, and results are presented which exhibit the long wavelength response, high quantum efficiency, and high frequency sensitivity expected. Measurements indicate no reduction in response at frequencies as high as 2000 Mc.

ISSN:0034-6748    

DOI:10.1063/1.1718049

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

An electromechanical device is described which will abruptly remove growing crystals from melts in order to preserve interfacial detail. High initial acceleration, of the order of a thousand gravities, is provided by an impact mechanism. This acceleration, the subsequent travel, and the damping are adjustable, and the entire sequence is triggered electrically. Dendritic samples of germanium indicate preservation of interfacial detail on a scale of a few microns.

ISSN:0034-6748    

DOI:10.1063/1.1718050

出版商:AIP    

年代:1962

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1718014

出版商:AIP    

年代:1962

数据来源: AIP