摘要:

The operating characteristics and design parameters of a high powered continuously pumped Nd:YAG laser are summarized. Primary attention is given to a discussion of some of the limitations in output power and efficiency.

ISSN:0034-6748    

DOI:10.1063/1.1684392

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

A unique low energy (0–50 keV) electron accelerator has been developed which provides a broad, parallel, low intensity electron beam with excellent long term stability. The beam intensity is approximately 106electrons·cm−2·sec−1and the long term stability is better than 2%/day. A prototype of this accelerator is described and the results of its application to instrument calibration and channel electron multiplier (CEM) efficiency measurements are presented. The absolute electron detection efficiency for CEM's was found to vary from approximately 90% at 1 keV to 73% at 14 keV with a probable error of ±10%. The large disagreement among the various published measurements of CEM detection efficiency is discussed.

ISSN:0034-6748    

DOI:10.1063/1.1684393

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

A technique is described whereby the density of diffraction spots on unidimensional x‐ray film is measured by means of a microdensitometer and recorded on a strip chart recorder; simultaneously, the area under the curve is integrated electronically and the results are displayed on a digital counting device. The data for one structure which has been completed gave a finalRvalue of 0.064.

ISSN:0034-6748    

DOI:10.1063/1.1684394

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

We have modified a standard Aminco‐Bowman spectrophotofluorometer to allow collection of spectral data on punched paper tape. Using this tape, we have obtained high quality corrected spectra by postprocessing techniques on a digital computer. We have examined the errors associated with changes in the energy distribution of the excitation source.

ISSN:0034-6748    

DOI:10.1063/1.1684395

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

An ac self‐balancing potentiometric photoconductive circuit has been developed and employed to measure resistive ratios. It includes a cadmium sulfide photoconductive cell and an incadescent lamp in an ac negative feedback configuration. The tested ratio is measured by incorporating the photocell in a dc circuit and monitoring the resulting current which is proportional to the tested ratio. Two specific examples are described, one of which is a precision circuit that was used to construct an inductive conductivity meter for oceanographic applications. By properly selecting the photocell type and increasing the open loop gain, a 0.1% accuracy (of full scale) may be obtained with a relatively simple circuit. The circuit is applicable for signal conditioning of resistive transducers such as platinum thermometers and strain gauges. It may be particularly useful in cases where a dc output signal is preferred while the resistive device must be driven by an ac signal.

ISSN:0034-6748    

DOI:10.1063/1.1684396

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

The electrical characteristic of gold and Aquadag contact with single crystal nickel oxide surfaces is determined within a moderate temperature range around 273 K. The current‐voltage characteristic of these contacts is linear, but the contact resistance is found not to be negligible when compared to the resistance of NiO samples of ordinary size.

ISSN:0034-6748    

DOI:10.1063/1.1684397

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

A method has been developed for determining the dynamic characteristics of a load cell element by subjecting it to sinusoidally time dependent forces, and an experiment using a piezoelectric shaker is described which illustrates the feasibility of the method. At present a simple viscoelastic model is assumed for the load cell element, and relaxation times on the order of 10−7sec have been measured. The application of this information to load cells subjected to other types of dynamic forces is also discussed.

ISSN:0034-6748    

DOI:10.1063/1.1684398

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

A quasi‐steady‐state, water cooled heat flux transducer has been developed for the measurement of heat fluxes exceeding 1000 W/cm2. The transducer utilizes single crystal germanium materials as the sensing elements and the design allows the transducer to be calibrated by direct conduction. Utilizing this technique, a transducer has been calibrated to 1000 W/cm2and the calibration has been verified by radiation techniques up to 455 W/cm2. Transducers only 1.1 cm in diameter have been tested. The transducers exhibit an output greater than 15 mV at 1000 W/cm2, a nearly linear output vs heat flux, and a response time on the order of 100 msec.

ISSN:0034-6748    

DOI:10.1063/1.1684399

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

A retarding field energy analyzer for photoelectron spectroscopy is improved by adding a screened field‐free region around the emitter. For preliminary measurements on nickel, the analyzer error was estimated to be <2.8% of the kinetic energy. The electronic circuit configuration which performed best is presented along with a description of spurious effects introduced by circuit variations.

ISSN:0034-6748    

DOI:10.1063/1.1684400

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

The theory of a simple inexpensive single plate interferometer coupled to a spectrograph is developed and the feasibility of this instrument in the hook method is demonstrated by observing the anomalous dispersion of sodium vapor. This instrument appears especially attractive for use in the vacuum ultraviolet region of the spectrum.

ISSN:0034-6748    

DOI:10.1063/1.1684401

出版商:AIP    

年代:1970

数据来源: AIP