摘要:

The design and performance of a capacitance manometer for use in corrosive gas laser environments is presented. This simple and inexpensive isolating device can be quickly fabricated in any machine shop, and permits the utilization of ordinary non‐passivated pressure measurement apparatus or gauges in any gas system, irrespective of the corrosiveness.

ISSN:0034-6748    

DOI:10.1063/1.1135788

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

The use of emissive Langmuir probes in unmagnetized and weakly magnetized multidipole plasmas is investigated. It is shown that plasma potential, plasma electron temperature, and probe temperature can be determined from one probe characteristic curve. Data indicate that the inflection point of the current‐voltage curve gives the plasma potential to an accuracy the order of the probe temperatureTw/efor weak probe emission. Effects of space‐charge limiting and contamination of the probe are presented.

ISSN:0034-6748    

DOI:10.1063/1.1135789

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

Individual x rays of 5.9 and 22.4 keV have been detected and energy analyzed in single pixels of a CCD image sensor. The results indicate the CCD operates as an array of tiny Si solid state detectors providing both high spatial resolution and x‐ray energy discrimination. These devices will prove useful sensors at the focus of future x‐ray telescopes.

ISSN:0034-6748    

DOI:10.1063/1.1135790

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

The new components required for bremsstrahlung isochromat spectroscopy (BIS) in UHV (10−12Torr range) have been developed and incorporated into an x‐ray photoelectron spectrometer. They consist of a Pierce electron gun and a soft x‐ray photon detector, both of which have to fulfill precise geometrical conditions imposed by the already existing monochromator. A description of the design and testing of this equipment is given. The resolution and the intensity appear to be correlated so that a compromise has to be found in order to achieve high resolution with acceptable intensity. It is demonstrated on the basis of suitable spectra that the density of unoccupied states above the Fermi level can be investigated with a resolution better than 0.43 eV.

ISSN:0034-6748    

DOI:10.1063/1.1135791

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

A method of accurately manipulating the pressure of helium gas in the rangeP=10−1to 10−20Torr,T<5 K is presented. The method requires only a very modest apparatus and makes use of thermodynamic measurements on the4He–Grafoil system. A calibration curve and a pressure scale for the manometer are developed which will allow convenient application in other laboratories. An experiment which utilizes the technique is briefly disscussed.

ISSN:0034-6748    

DOI:10.1063/1.1135792

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

A sample rotator which operates in applied magnetic fields is described. The design eliminates mechanical linkages by magnetically orienting a gimbal ring. Three mutually orthogonal coils mounted on the gimbal provide a magnetic moment which is aligned along the field direction. The rotator is useful from room temperature down to the liquid helium range. Rotations about any desired axis are possible.

ISSN:0034-6748    

DOI:10.1063/1.1135793

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

A fast response magnetic loop current monitor has been developed to measure relativistic electron beam return currents. The monitor has a rise time of about a nanosecond and a high degree of symmetry with moderate sensitivity, variable from about 1 to 10 V/kA. This simple monitor, with a thickness of 0.254 mm or less, is thin enough to be placed between segments of return current path in the diode or drift tube regions, is insensitive to flashover, beam and plasma bombardment, and radiation effects, and measures net current, thus offering some advantages over conventional magnetic probes, since the main components are outside of the vacuum region. Design criteria, an equivalent circuit analysis, and typical calibration waveforms are presented. Experimental current measurements for a pinched electron beam diode configuration using both conventional magnetic probes and ’’gasket‐type’’current monitors with the FX‐75 relativistic electron beam accelerator are presented.

ISSN:0034-6748    

DOI:10.1063/1.1135794

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

A system for dispensing and continuously measuring the flow of solid particles into a hot high‐pressure gas flow for times up to 1 h is described. A differential pressure across an orifice is used to force the particle flow. A strain gauge load cell is used to continuously sense the weight of the container from which the particles are being dispensed. Calibration results are included for flows of 100‐&mgr;m‐diam glass spheres through several orifices at rates from 1 to 15 g/s.

ISSN:0034-6748    

DOI:10.1063/1.1135795

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

In this paper we report on a new optoacoustic apparatus designed for the study of highly corrosive gases. The sound transducer is a thin quartz membrane sintered to one end of the solid quartz acoustic chamber. Measurements were performed on iodine chloride. Construction details, performance characteristics and the usage of the system in the study of the photo‐induced reaction between ICP and C2H2are described.

ISSN:0034-6748    

DOI:10.1063/1.1135802

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

A stress apparatus is reported which allows us to apply forces up to 300 N to solids perpendicular to the field in a superconducting magnet. This configuration is necessary to study stress dependences of transverse magneto‐transport effects and magneto‐optical properties in Faraday geometry. The usefulness of the apparatus is demonstrated by Hall effect and transverse magnetoresistance measurements in n‐InSb as well as far‐infrared cyclotron resonance experiments on n‐Ge.

ISSN:0034-6748    

DOI:10.1063/1.1135803

出版商:AIP    

年代:1979

数据来源: AIP