摘要:

Sturdy silicon transmission counters as thin as 0.0012 in. were produced and used in conjunction with a passive pulse‐adder circuit which combined thedE/dxandEpulses so that the nonuniformity and energy straggling in the transmission counter would not decrease the resolution of the energy spectra. Construction and performance of these counters are described.

ISSN:0034-6748    

DOI:10.1063/1.1717940

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

The possible advantages and disadvantages of driving cryotron circuits with a low impedance transmission system instead of a high impedance system are discussed. It is shown that although losses are higher in a low impedance cable, a reduction in the signal coupled between cables in a cryotron system is possible when low impedance cable is used. Two low impedance generators are described. These generators have a maximum frequency between 500 kc and 1 Mc. The rise time is less than 2 nsec and can be improved when the generators are packaged in strip line module form. Pulse amplitude is about 1.5 A. Pulse width is variable by use of a delay cable.

ISSN:0034-6748    

DOI:10.1063/1.1717941

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

Apparatus has been designed and constructed capable of measuring the photo‐Hall effect for mobilities as low as 0.1 cm2/V‐sec, in photoconductors with resistivity as high as 1010&OHgr;‐cm, over the temperature range from 77 to 450°K. Temperature control of the photoconductor crystal by thermal conductivity through gaseous helium eliminates many of the problems associated with temperature control by direct thermal contact to the crystal. Voltage signals down to 100 &mgr;V are detected by vibrating reed electrometers, using five contacts to the crystal.

ISSN:0034-6748    

DOI:10.1063/1.1717942

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

A manufacturing technique is described by which one can make low intensity (∼5×10−6ergs/cm2sec sr in units of astronomical photographic intensities at &lgr;=4300 and &Dgr;&lgr;=1290 Å) standard light sources by the polymerization of an organic plastic scintillator containing a low energy &bgr; emitter.

ISSN:0034-6748    

DOI:10.1063/1.1717943

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

Distorted spectra were obtained when the Mn K x‐ray peak was observed in a proportional counter filled with CO2and small pressures of the counter poison O2. The spectra can be explained with the assumption that the only effect of the poison is to capture electrons as they drift toward the anode. The rate of attachment of electrons at an average electron energy of 0.054 eV and 298°K was found to be equal toK2(O2)+K3(O2)(CO2), where the values ofK2andK3are 5×10−12cc/sec and 1.7×10−30cc2/sec, respectively.

ISSN:0034-6748    

DOI:10.1063/1.1717944

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

The paramagnetic or diamagnetic susceptibility of microgram amounts of solid samples can be measured by a null method in which the force of gravity balances the force on the sample due to an inhomogeneous magnetic field. The method measures the largest principal susceptibility of magnetically anisotropic crystals.

ISSN:0034-6748    

DOI:10.1063/1.1717945

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

Use of a traveling wave helix for concentrating microwave fields is discussed, with special attention given to application to electron spin resonance and Overhauser effects (double magnetic resonance). Some practical design considerations are treated. The influence of the standing wave pattern in the helix is treated in the Appendix.

ISSN:0034-6748    

DOI:10.1063/1.1717946

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

A water‐cooled gas sampling probe capable of steady‐state operation at 15 000°K and one atmosphere has been developed. Temperature is measured by a calorimetric technique which can provide high‐accuracy calibration under arcjet conditions. The probe also measures velocity and chemical composition and, because of its small size (∼⅛ in. o.d.), is capable of accurate local measurements in the presence of severe gas‐stream property gradients. Calibrations in the partially ionized argon‐helium environment of an arcjet exhaust indicated an average agreement with mass and energy balance criteria within ½%, and a standard deviation from the mean of less than 3%.

ISSN:0034-6748    

DOI:10.1063/1.1717947

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

A total absorption scintillation counter for high‐energy photons has been developed with ±7% energy spread for 130‐MeV photons. The counter was built of enough plastic scintillator to contain most of the energy and maintain a high detection efficiency. We employed the technique of observing a statistical sampling of light from an integrating volume. The integrating volume was obtained by painting the surface of the counter with a diffuse reflector and detecting the light with a large number of photomultiplier tubes placed symmetrically about the counter. Use of a scintillator enabled us to work with a light source of high intensity, thus assuring optimum photon statistics.

ISSN:0034-6748    

DOI:10.1063/1.1717948

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

A method for sputtering simultaneously from electrically independent electrodes is described. The important design consideration is that the electrodes (cathodes) are enveloped by a single Crooke's dark space. Using this technique, alloy films (or in the case of reactive sputtering, mixed compound films) can be obtained. Since the electrodes are independent, the composition gradient (in depth) of the film can be varied at will by proper variation of applied voltages.

ISSN:0034-6748    

DOI:10.1063/1.1717949

出版商:AIP    

年代:1962

数据来源: AIP