摘要:

A one‐film method for orienting single crystals using an oscillation film obtained with a Weissenberg camera is described. Highly precise orientation corrections are obtained by using the curvature of the nonzero lines, which is more sensitive to crystal orientation than the zero layer line curvature used in other methods. The equations used for the corrections are derived, rather than empirical, and a general equation for the shapes of the lines caused by a misoriented crystal is given.

ISSN:0034-6748    

DOI:10.1063/1.1720658

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Measurements in the temperature range 0.4 to 3°K have shown that the specific heat of American Smelting and Refining Co. 99.999+% pure copper in the ``as received'' condition may be higher than the specific heat of samples which have been vacuum annealed or vacuum cast from this material, possibly due to the presence of a dissolved gas. The specific heat of copper has been increased (by a percent or so) by heating in a hydrogen atmosphere. The effect of very low levels of transition metal impurities on the specific heat is discussed.

ISSN:0034-6748    

DOI:10.1063/1.1720659

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

It is shown that the procedure of evaluating pressure losses in internally‐heated piston‐cylinder devices by assuming symmetrical friction is in error below ∼500°C. Previous results may be in error by as much as ∼5 kilobars at 40 kilobars and 25°C. A method of calibration is described which evaluates such unsymmetrical pressure losses.

ISSN:0034-6748    

DOI:10.1063/1.1720660

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

A hollow‐cathode carbon resonance lamp was constructed, and the effect of anode configuration, filler gas (helium, argon, and neon), filler‐gas pressure, and lamp current on the intensity of enission lines in the region 1560 to 2000 Å was studied. The carbon resonance triplet at 1657 Å could be obtained with good intensity, as could the carbon line at 1931 Å. The spectrum also showed a number of molecular bands, one of which interfered slightly with the carbon resonance line at 1657 Å. The bands could be removed, however, by reducing the pressure of the filler gas.

ISSN:0034-6748    

DOI:10.1063/1.1720661

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

An insensitive gamma‐ray detector for measurement of fast rising, transient gamma‐ray fluxes has been developed. Linear signals ≥5×102A have been observed, corresponding to a 1.25 MeV dose rate of >1016R/h. The detector can also be used in the steady state mode where signals ≤10−12A can be measured. This current corresponds to a60Co dose rate of ∼20 R/h. Detector design criteria, sensitivity as a function of energy, linearity, and time response are also discussed.

ISSN:0034-6748    

DOI:10.1063/1.1720662

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

The field produced by a quadrupole magnet is antisymmetric with respect to reflection through either of two orthogonal planes whose intersection is the optical axis of the magnet. Failure to perfectly align these planes for a given quadrupole magnet with the cardinal planes of the beam system incorporating that magnet induces an error field that perturbs the beam. The effects of misalignments of a number of quadrupoles are derived by including the induced error fields in the equation of motion. The results are expressed in terms of the known linear optical properties of the beam system and are sufficient for determining the tolerances required on each constituent quadpole magnet.

ISSN:0034-6748    

DOI:10.1063/1.1720663

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

An apparatus for making recorded kinetic measurements on reacting systems involving gases and solids or liquids has been constructed and tested by studying the decomposition of benzene diazonium chloride. In operation, helium is flowed through one side of a thermal conductivity detector (TCC), an equilibration tube containing solvent (if necessary), through the reactor, and back through the other side of the TCC. The measurement is made under conditions of programmed ambient temperature. The resulting recorder pen displacement is proportional to the concentration of gas in the helium stream, and, with appropriate apparatus design, to the rate of evolution of nitrogen. The skewed bell curve which results can be analyzed for the kinetic data. At each temperature (time) the pen displacement is a direct measure of the reaction velocity. The measurement has thus resulted in a transformation from a differential to an algebraic kinetics expression. The area under the curve to any temperature (time) is proportional to the total amount of gas produced. In a calibrated apparatus, one thus has a continuous analysis of the reaction. Treatment of the data to obtain an Arrhenius expression is a fairly straightforward procedure, programmable for computer solution. The example of reaction chosen is the decomposition of benzene diazonium chloride. The results are compared with literature values.

ISSN:0034-6748    

DOI:10.1063/1.1720664

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

A closed feedback loop for the zero velocity drift of a constant acceleration Mo¨ssbauer spectrometer has been developed. Using a transducer with a built‐in limit switch and the modified logic circuitry of a multi‐scaler‐analyzer, the feedback loop responds to the zero velocity drift of the entire system as a whole rather than to each component independently. A long‐term zero velocity stability of ±0.001 mm/sec has been obtained.

ISSN:0034-6748    

DOI:10.1063/1.1720665

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

A laser calorimeter has been developed based on the pyroelectric effect. This radiation sensing mechanism is independent of the temporal and spatial distribution of incident energy. Calibration with sources of known power and comparison with other methods of measurement indicate an absolute accuracy of better than ±5%.

ISSN:0034-6748    

DOI:10.1063/1.1720666

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

A method is described which allows the direct and continuous recording of the critical current versus magnetic field curves for superconductors. The system uses an electronic integrator to control a current supply so as to produce a selected small voltage across the sample. It presents an improvement in both speed and ease of obtaining critical current curves.

ISSN:0034-6748    

DOI:10.1063/1.1720667

出版商:AIP    

年代:1967

数据来源: AIP