摘要:

It is common practice in schlieren optical systems to use a phase plate diaphragm incorporating a fine wire. The optical theory of such diaphragms is, however, complex, and their behavior over a range of refraction gradients has never been critically evaluated. It is shown that the older knife edge diaphragm, the optics of which are relatively simple, can be used in conjunction with modern double‐sector ultracentrifuge cells, thus providing a reference standard against which the behavior of a phase plate diaphragm can be checked over a range of conditions. Results are presented showing near ideal behavior for an MSE phase plate.

ISSN:0034-6748    

DOI:10.1063/1.1684910

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

A system has been constructed to study very small asymmetries in the directional distribution of &ggr; radiation from polarized nuclei. The system combines the ultralow temperatures of a3He&sngbnd;4He dilution refrigerator (down to 14 mK) and the large hyperfine field of a ferromagnetic host lattice. The hyperfine field direction is smoothly and continuously rotated by means of an external field to compare the &ggr;‐ray intensity in different directions. Many experimental tests have been performed, and upper limits are placed on various sources of spurious asymmetry.

ISSN:0034-6748    

DOI:10.1063/1.1684911

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

A photoelectron spectrometer composed of a cylindrical mirror type of electron energy analyzer and an Al K&agr; x‐ray source is described. Performance tests with a tungsten filament and with gold samples have proved that the analyzer performs well. The doublet peaks of N6and N7of gold were completely resolved, and half‐widths of the two peaks were both found to be about 1.5 eV, which is comparable with the value of 1.3–1.4 eV given by Siegbahnet al.with Mg K&agr; x rays.

ISSN:0034-6748    

DOI:10.1063/1.1684912

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

A laboratory gas circulation pump has been built in which the pump driving force is obtained by the alternate decomposition and regeneration of vanadium dihydride (VH2). This cyclic action is accomplished by alternately heating and cooling the hydride system using hot (50°C) and cold (18°C) water. The particular pump described is suitable for the circulation of gases in systems where the pressure range is between 7 and 24 atm.

ISSN:0034-6748    

DOI:10.1063/1.1684913

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

A small device consisting of a lamp, filter, and external photodiode has been used successfully to monitor the sensitivity of a Lyman‐alpha photometer on OGO‐6 as well as a number of Air Force satellites. The operation of this calibration device is independent of lamp, filter, or window decay.

ISSN:0034-6748    

DOI:10.1063/1.1684914

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

Laser‐induced vibrational fluorescence experiments have been accomplished with a newly developed cw chemical laser. The design and operating characteristics of this small‐scale transverse flow chemical laser source are presented. The fluorescence measurement technique and apparatus provide several advantages over the use of pulsed chemical lasers for similar measurements. The present laser is also useful as a selectively tunable probe for single pass gain measurements in chemical lasers.

ISSN:0034-6748    

DOI:10.1063/1.1684915

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

Practical details of a scanning low energy electron probe (SLEEP) are described. The SLEEP incorporates a demountable electron optical system (EOS) with a triode type gun, an electrostatic and a magnetic lens, and a magnetic scanning system. The cathode is at approximately ground potential. The EOS can be operated satisfactorily at anode voltages between 500 V and at least 10 kV and produces an electron beam of between 5 and 25 &mgr; in diameter which can be scanned over a mesh electrode of 5 cm in diameter. The specimen is placed beyond the mesh electrode but close to it and the electron beam decelerates in the region between mesh and specimen and is partially reflected from the specimen. Electronic circuits for measurements and the control of the EOS are described, and the practical limitations to be expected are discussed briefly. Instruments of this type can be used to make quantitative measurements of electrical parameters. Applications of the SLEEP are discussed briefly.

ISSN:0034-6748    

DOI:10.1063/1.1684916

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

Routine reaction rate comparison studies of highly corrosive gaseous fluorides, such as CIF3and F2, extending to temperatures above 100°C required the development of an improved heated ir gas cell. The cell features cooled window gaskets composed of Teflon, all nickel construction, and a tapered sample space to reduce the internal volume. The internal temperature of the cell can be accurately determined and controlled by the use of parameter design charts to set the control variables. The cell, which has proven to be reliable and easy to operate for the intended service, has also been extended to applications requiring vaporizing air sensitive compounds onto the cooled windows for direct ir observation.

ISSN:0034-6748    

DOI:10.1063/1.1684917

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

The limitations of the RC filter for making measurements on resonance type signals are examined by comparing it with the matched filter. An approximate matched filter for measuring amplitudes that require no previous knowledge of the signal is presented and compared with both the matched filter and the RC filter.

ISSN:0034-6748    

DOI:10.1063/1.1684918

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

The 240 MeV electron storage ring at the University of Wisconsin Physical Science Laboratory provides an intense polarized continuum light source in the far ultraviolet. Experimental equipment is described which allows the measurement of optical reflectivity and absorption of solids in the photon energy range 6–36 eV at temperatures between 90 and 500 K with this source. A discussion of the experimental procedures and the performance of the system is presented.

ISSN:0034-6748    

DOI:10.1063/1.1684919

出版商:AIP    

年代:1971

数据来源: AIP