摘要:

This paper describes an apparatus for measuring the contact angle between an air bubble and the underside of a solid surface to which the bubble adheres. This general method of measurement of contact angles replaces the usual sessile drop method. The purpose of submerging a bubble in the liquid is to assure an equilibrium vapor pressure, so that, in case of solutions, the surface concentration does not change during measurement. The apparatus was especially designed to study the interfacial energies between saturated solutions and the various faces of a chosen crystal.

ISSN:0034-6748    

DOI:10.1063/1.1134019

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

MASS 3I8−90 type apparatus is developed to generate pressures up to 500 kilobar in a volume of 7.5 mm3. The geometry, operational mechanism, and the result of the pressure−generating experiment are described in detail.

ISSN:0034-6748    

DOI:10.1063/1.1134032

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

A new design for a telefocus electron gun is presented. Features include a nearly constant minimum FWHM of 180 &mgr; with beam currents of 1−400 &mgr;A at focal distances from 1/2 to 1 1/2 m. The gun is especially designed to operate under adverse vacuum conditions with background pressures as high as 10−4Torr with accelerating potentials of 10 to 60 keV. In addition tn can be remotely focused and positioned from outside the vacuum chamber in which the gun is used.

ISSN:0034-6748    

DOI:10.1063/1.1134033

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

An electron impact spectrometer for operation in the keV incident−electron energy range is described. The spectrometer operates between 20 and 60 keV incident−electron energy, utilizing both a low−resolution silicon surface barrier detector (5 keV FWHM), and a high−resolution (0.7 eV FWHM) Mo¨llenstedt energy analyzer over a 1.7 keV energy loss range. It features a large angular scan range (0⩽&Vthgr;<120°), high target gas throughput (i.e., 19000 l/sec for He and 13000 l/sec for N2through a tube of 0.15 mm diam), and a wide range of incident−electron beam currents (0.1−400 &mgr;A) with a focused electron beam size of less than 200 &mgr; FWHM over most of the current range. Careful measurements of the gas density profile of the target gas emanating from the nozzle are also reported. Results are presented for the Bethe surface of He and N2. The latter example is reported here for the first time. In addition, the observation of the angular dependence of the Lyman−Birge−Hopfield band in N2(dipole forbidden) is compared with the dependence of a neighboring dipole allowed transition.

ISSN:0034-6748    

DOI:10.1063/1.1134034

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

A scattering chamber for use in atomic collisions experiments is described which utilizes a simple sliding seal and which has an angular range of 20−160°.

ISSN:0034-6748    

DOI:10.1063/1.1134035

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

An assembly for capturing fragments of toxic materials used in plate impact tests is described.

ISSN:0034-6748    

DOI:10.1063/1.1134036

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

An extremely simple and inexpensive technique by which holes of uniform bore can be produced in copper is described. Measured uniformity may exceed 2500 A˚ on a bore diameter of 6.35 mm.

ISSN:0034-6748    

DOI:10.1063/1.1134039

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

A sample holder for either transmission or reflection measurements is described. Basically a length of five−wire or ’’cage’’ transmission line, when terminated with a 50 &OHgr; load it exhibits (in air) a residual VSWR of less than 1.05 below 2.0 GHz and (with one exception) less than 1.08 up to 6.0 GHz. Designed for use with solid samples, it may be adapted to powders or fluids.

ISSN:0034-6748    

DOI:10.1063/1.1134041

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

The pile−up circuit described has been tested at random rates to 80 000 pps with a pulse pair resolution of 20 nsec. The unit features integrated circuits for decision−making logic.

ISSN:0034-6748    

DOI:10.1063/1.1134042

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

High−quality skimmers for supersonic molecular beams may be fabricated in a variety of shapes by a method which involves both electroforming and machining operations.

ISSN:0034-6748    

DOI:10.1063/1.1134043

出版商:AIP    

年代:1975

数据来源: AIP