摘要:

A system of two detectors separated by a narrow gap provides information regarding the diameter and flux distribution of small focused light spots. Differential signal variations in response to gap position for three flux distributions are theoretically analyzed: constant intensity, linearly diminishing intensity, and Gaussian. A PbZrTiO3pyroelectric split detector was fabricated for analyzing spots as small as 6 &mgr; (half‐intensity diam). Data taken on a focused He&sngbnd;Ne laser spot (≈25 &mgr; half‐intensity diam) are compared with expectation curves. Suggestions for improving resolution and sensitivity are made.

ISSN:0034-6748    

DOI:10.1063/1.1684199

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

The decrease of the quenching agent found in aged counters (approximately 2×108counts registered) is of the order of 0.5%. This cannot account for their bad functioning. Only changes on the anode surface (polymer deposit) and in the gas phase (new products formed by counter discharge) are responsible for the deterioration of aged self‐quenching G‐M counters. The first mentioned changes are neutralized by simply glowing the wire, the latter may be overcome by the choice of a suitable quenching agent. C2H5CN gives better results than C2H5OH.

ISSN:0034-6748    

DOI:10.1063/1.1684200

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

An optical instrument, utilizing a light reflection principle, has been designed which is capable of determining not only surface slope, but also surface curvature distribution. This instrument has been successfully tested in laboratory studies of wind generated waves. Some sample results are included to illustrate the applicability of the instrument.

ISSN:0034-6748    

DOI:10.1063/1.1684201

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

Aligning, calibrating, and systems testing of automatic ir optometers are greatly facilitated by using a liquid filled analog of the human eye. Characteristics of the eye analog that render it useful as a test element are (1) corneal refractive power comparable with that of the human eye, (2) spectral transmission properties similar to those of the ocular media, (3) rotatable cornea for simulation of astigmatism of any axial orientation, (4) movable fundus (image screen) to simulate an adequate range of refractive errors, and (5) easily replaceable cornea to obtain different amounts of astigmatism.

ISSN:0034-6748    

DOI:10.1063/1.1684202

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

The space charge in a gas filled proportional counter resulting from the slowly moving positive ions as they drift from the central wire toward the outer shell is known to cause a significant change in the position and breadth of the energy peak created by monoenergetic x rays. A quantitative theory for the mean shift is developed and confirmed experimentally.

ISSN:0034-6748    

DOI:10.1063/1.1684203

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

An inexpensive modification of a commercial mass spectrometer is described which permits linear display of ion intensity vsm/eon an X‐Y recorder. Its evaluation shows that the major limitations arise from recorder specifications. For magnetically scanning instruments, mass assignments can be made within ±0.006% utilizing the maximum zero offset of 85% of the largest mass of interest. Peak positions are independent of scanning speed up to 30m/eunits/min and can be assessed within 0.1% of the mass range covered.

ISSN:0034-6748    

DOI:10.1063/1.1684204

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

A technique has been developed for producing freely falling pairs of water drops with unequal radii. Radius ratios as large as 10 to 1 can be obtained with drops having radii in the range 0.1–1.0 mm. Continuous production of drop pairs is possible, with the desired repetition rates selected by electronic controls and unwanted drop pairs deflected out of the observation volume. Successive pairs, thus produced, are sufficiently identical that a sequence of photographs has been obtained with an effective elapsed time between exposures of 100 &mgr;sec, the equivalent of 10 000 frames/sec in terms of high speed photography.

ISSN:0034-6748    

DOI:10.1063/1.1684205

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

In conducting constant stress creep tests of ductile metals means must be provided to alter the applied load in response to changes in specimen geometry. Over the years a variety of automatic devices has been developed which compensates for the limited range of geometrical change usually encountered. Interest in superplastic metals exhibiting homogeneous plastic deformations of several hundred percent and total extensions of up to 2000% at almost zero applied stress levels creates the need to extend the techniques of creep testing. In this investigation it was desired to keep the test apparatus as simple as possible to permit its use in a variety of test programs, including elevated temperature and combined creep‐fatigue experiments. As a result, a design was developed which permitted the application of very low stresses stimulating quasistatic creep rates over a 20 to 1 strain range, as well as higher stress configurations required to produce significantly elevated creep rates. Test results with a low stress prototype provide creep data for a superplastic lead‐tin alloy over a range of very low strain rates both with and without superimposed fatigue.

ISSN:0034-6748    

DOI:10.1063/1.1684206

出版商:AIP    

年代:1969

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1684207

出版商:AIP    

年代:1969

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1684208

出版商:AIP    

年代:1969

数据来源: AIP