摘要:

A combination glove box–sample compartment cover has been constructed for a rapid scan Fourier transform ir spectrophotometer so that greater advantage can be taken of the speed and sensitivity of this type of instrument. While maintaining the atmospheric purge throughout the sample and optical chambers of the instrument, the cover provides routine operator access to the interior of the sample chamber and a pathway for interchanging samples.

ISSN:0034-6748    

DOI:10.1063/1.1134353

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

We report on the construction and calibration of a 6 m2scintillation counter. The counter consisted of two 1.22×2.44×0.051 m pieces of clear Lucite which were optically joined along a common edge. Optically coupled on top of these were sixteen 0.61×0.61×0.019 m squares of NE 110 plastic scintillator. Light collection was achieved with eight photomultiplier tubes. This counter had an operational attenuation length of 4.8±0.9 m. Calibration of this counter with an anticoincidence counter to discriminate against multiple particle events is described. This anticoincidence counter permitted particles that passed through a small calibration area to be counted only if no other particles were passing through the remainder of the detector at the same time. Large area counters will often receive more than a single particle per event. Theoretical calculations for purely electromagnetic extensive air showers indicate that the 6 m2counter tested receives an average of 2.5 particles per event. The calibration data yield 1.79±0.08 particles per event. These results imply that if calibration on the response from a single particle of an extensive air shower is desired, it is necessary to use the anticoincidence counter method described for counters of more than a few square meters area.

ISSN:0034-6748    

DOI:10.1063/1.1134354

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

A relatively simple microcomputer interface for data acquisition from pulsed NMR experiments is described. The timing of the sampling of the NMR signal is performed by the interface itself, based on the pulses delivered by the spectrometer‐pulse programmer. The acquired data are stored in a buffer memory and after completion of the experiment can be transferred into the computer for further processing.

ISSN:0034-6748    

DOI:10.1063/1.1134330

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

This hygrometer is designed to measure the humidity of atmospheric air over the vapor pressure range 3–7400 Pa (0.03–74 mbar). The instrument is an adaptation of a microwave refractometer using two cavities operating at 12 GHz. One cavity is exposed to the moist test air and the other is exposed to the same air sample with all the water vapor removed. Both cavities are maintained at the same fixed temperature in a thermostated oven and at the same total pressure. The difference in frequency between the cavities is automatically nulled by a tuning probe in the sampling cavity. The instrument was calibrated by two independent methods. One involved the measurement of the resonance frequency of the sampling cavity as a function of probe penetration and using this in a theoretically derived equation for vapor pressure. The second involved the measurement of the probe penetration as an empirical function of known vapor pressure of a test gas. These two methods yielded results which agreed on the average to better than 0.5% for vapor pressures up to 3050 Pa (30.5 mbar).

ISSN:0034-6748    

DOI:10.1063/1.1134331

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

An EPR cavity system, operating in the range 12 K to room temperature, is described. Sample cooling is accomplished with a Displex helium gas refrigerator, operating for arbitrarily long periods with the use of only electricity. The system permits accurate rotation and manipulation of single crystal samples throughout its operating range.

ISSN:0034-6748    

DOI:10.1063/1.1134332

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

The principle of the branched fiber bundle sensor has been known for many years. The apparatus which is described in this paper is distinguished by simple fabrication, low cost, high sensitivity, and a fast response time. It is used for measuring the velocity of the back surface of an irradiated aluminum target. In spite of intense consecutive bremsstrahlung, the plastic fiber probe gives good results, whereas with glass fiber a large scintillation impulse appears which covers the signal.

ISSN:0034-6748    

DOI:10.1063/1.1134333

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

A simple, inexpensive comparator circuit and its associated equipment providing automatic Bragg angle control (ABAC) and allowing determination of lattice curvature and film stresses with scanning x‐ray topographic cameras is described.

ISSN:0034-6748    

DOI:10.1063/1.1134334

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

A double coil differential magnetic probe has been specifically devised for the measurement of magnetic fields with high temporal and spatial resolution. Having a response time of <1 nsec, a sensitivity of 0.3 V nsec G−1, and high discrimination (≳300) to all other types of background interference, it is well suited to the analysis of magnetic fields associated with plasmas produced by ultrashort laser pulses.

ISSN:0034-6748    

DOI:10.1063/1.1134335

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

A contained scanning electron microscope (CSEM) was designed and constructed at the Savannah River Laboratory. The facility consists of two stainless‐steel glove boxes with separate compartments for specimen mounting and coating, specimen decontamination, SEM column and sample chamber, and containment of the vacuum pumping systems.

ISSN:0034-6748    

DOI:10.1063/1.1134336

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

An electronic device is described by which the rest position of a mechanical oscillating system can be locked onto a given point or angle. This is obtained by generating a square wave that develops a dc component every time the rest position of the system does not coincide with the required one, and by making a motor automatically displace the oscillation center until the dc component of the square wave is zero. The device has been tested in connection with a torsion pendulum for internal friction measurements: it can correct large displacements of the rest position of the oscillating pendulum within few a periods, provided the angular velocity of the compensation motor is suitably chosen in relation to pendulum oscillation amplitude and period.

ISSN:0034-6748    

DOI:10.1063/1.1134337

出版商:AIP    

年代:1975

数据来源: AIP