摘要:

A very simple logarithmic response dc electrometer circuit is described which makes use of a novel connection for developing the log feedback signal. The resulting improvement in bandwidth over familiar circuits is discussed.

ISSN:0034-6748    

DOI:10.1063/1.1683997

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

A drop, whose size may lie between 0.4 and 2.0 mm, is blown from a capillary tube tip as it reaches a given size. Drop size and frequency may be varied independently by controlling liquid flow rate and pulse rate.

ISSN:0034-6748    

DOI:10.1063/1.1683998

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

A calorimeter utilizing a differential emissivity thermopile to measure directly the radiant heat exchange of small animals is described. Other modes of heat exchange are effectively eliminated by containing the animal in an infrared transparent container. Noise on low level signals is minimal due to a special heat sink design. Construction details, optimization, calibration, and the validity of negative thermopile signals for radiant energy absorption are discussed.

ISSN:0034-6748    

DOI:10.1063/1.1683999

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

A crossed‐beam apparatus for the study of ion‐molecule reactions is described. The device can provide information on the velocity and angular spectra of reaction products as well as on the angular displacement between reactant and product ions. It can thus yield data sufficient to provide a detailed characterization of the dynamics of the system studied. Furthermore, the mass selected ion beam is variable in energy from 100 eV down to the critical low energy region of about 1 eV or less. Although the apparatus thus seems to have broader capabilities than previously described beam devices, it is quite small and comparatively inexpensive.

ISSN:0034-6748    

DOI:10.1063/1.1684000

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

An oxide semiconductor thermistor for application in the range 1000–2500 K was designed, fabricated, and tested. Construction materials consisted of zirconia with 15 mole % yttria as the sensor element, iridium plus 40 wt% rhodium as the lead wires, and beryllium oxide as the insulating material. Sensors were tested for resistance and voltage characteristics, thermal shock resistance, stability, sensitivity, and response. Linearized temperature indication and time lag compensation are also discussed.

ISSN:0034-6748    

DOI:10.1063/1.1684001

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

A millimeter‐wave electron spin resonance spectrometer working in the E band (67–74 Gc) has been assembled. Features connected with the use of millimeter waves, in particular the microwave cavity, the low temperature assembly, and the klystron stabilization, are described in detail. Furthermore the spectrometer design as a whole and the sensitivity obtained are discussed.

ISSN:0034-6748    

DOI:10.1063/1.1684002

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

The target attenuation correction factor is given for the situation in which the attenuation coefficients differ for incident and scattered radiation. The calculation applies for cylindrical targets, with the scattering plane perpendicular to the cylinder axis. The correction factor is expressed in the form of a series expansion which is appropriate for cases of small attenuation.

ISSN:0034-6748    

DOI:10.1063/1.1684003

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

An apparatus is described which has been developed to shear bulk samples under nearly hydrostatic pressure. This apparatus gives complete stress‐strain curves in the plastic region at pressures from about 10 to approximately 70 kilobars.

ISSN:0034-6748    

DOI:10.1063/1.1684004

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

A simple current‐to‐frequency converter has been developed which works directly with photomultiplier currents. It has full scale input current ranges of 3×10−10to 3×10−6A. The feedback pulse is a square pulse that is clocked on and off by a continuously running oscillator. Drift in the oscillator frequency is compensated if the oscillator also serves as the time base of the counter used to count the pulses. With oscillator frequencies up to and including 20 kHz the linearity is 0.01% or better and the drift less than 0.01% of full scale per hour.

ISSN:0034-6748    

DOI:10.1063/1.1684005

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

By exploding a thin tungsten wire in vacuum, it is found that an ultrafast (20 nsec half‐width), reproducible x‐ray pulse is emitted from the wire during the first half‐cycle of the discharge. The half‐width of the pulse seems to be independent of the ringing frequency of the discharge circuit. It is shown that it is possible to use the exploding wire as a flash x‐ray source for taking radiographs of high speed events, e.g., an exploding copper wire.

ISSN:0034-6748    

DOI:10.1063/1.1684006

出版商:AIP    

年代:1969

数据来源: AIP