摘要:

An oscillating rectangular vane suspended by a fine quartz fiber is used to determine the absolute pressure of the gas in which it is located. Aside from being an absolute instrument, the advantages of such a device are (1) simplicity, (2) the fact that it does not change the pressure when an observation is made as do many other types of gauges, and (3) the absence of a heated filament which may decompose the gas under study.

ISSN:0034-6748    

DOI:10.1063/1.1717976

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

A new transducer has been developed that will measure pressure over a wide range by sensing the damping of a vibrating diaphragm immersed in the gas whose pressure is being measured. It is capable of measuring pressures from approximately 10−5to 200 mm Hg with an accuracy of about 1% over a large portion of the range. The device overcomes many of the shortcomings characteristic of other gauges; it is small and rugged, with a fast response time at low pressures, and lends itself well to automatic operation.

ISSN:0034-6748    

DOI:10.1063/1.1717977

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

This report describes work undertaken to design and build a pressure gauge utilizing a unique pick‐off which couples the phenomena of electroluminescence and photoconductivity to obtain a completely solid‐state device having a low impedance output capable of detecting very small mechanical displacements (microinches) of bellows and diaphragm pressure sensors. Advantages of this device as applied to pressure measurement are small size and weight, very high resistance to shock and vibration, and continuous resolution over a wide dynamic range. A prototype pressure gauge capable of measuring pressures from 0 to 800 mm Hg and having an electrical output of 1 to 5 V when operated from a 28‐V dc power source is described.

ISSN:0034-6748    

DOI:10.1063/1.1717978

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

The intensity and decay time of Po210alpha particle scintillations produced in pure and thallium‐activated cesium iodide have been measured with a fast electronic system as a function of temperature down to 77°K. Three modes of decay due to alpha excitation have been observed for CsI(Tl), and two for CsI. Other than the 7‐ and 0.55‐&mgr;sec modes (at room temperature) reported in the literature for CsI(Tl), an additional temperature‐independent mode of about 1.3 &mgr;sec has been detected between 77 and 150°K. In CsI a fast temperature‐dependent mode of decay (≈100 nsec) was observed between 100–200°K in addition to the known principal mode.

ISSN:0034-6748    

DOI:10.1063/1.1717979

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

The focusing properties of a quadrupole lens pair have been studied under conditions to produce a wedge‐shaped ion beam for a mass spectrometer. The lens equations have been analyzed numerically and resulting graphs are given for the determination of various lens parameters.

ISSN:0034-6748    

DOI:10.1063/1.1717980

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

Power transistors delivering 8‐A pulses of 2‐msec width are used to drive low impedance coils in Ross and Barksdale valves. Unijunction transistors and Thyristors are used to replace all relays and lamp flasher elements in compact, reliable alarm units of new design. Life tests equivalent to many years operation at accelerator sites have been carried out. There has not yet been any failure in operation.

ISSN:0034-6748    

DOI:10.1063/1.1717981

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

A system is described which provides a triggering signal for a scintillation or spark chamber from a coincidence circuit. Power is supplied to label the recording film with a register number and to advance the film to a clear position. Multiple exposures of events are prevented.

ISSN:0034-6748    

DOI:10.1063/1.1717982

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

The apparatus described in this paper can be used to grow alkali halide single crystals of several hundred grams from the melt in less than 48 h per crystal. The growth is carried out in a cylindrical quartz enclosure in a selected gas atmosphere which is maintained at a slight positive pressure by continuous inflow of gas. The gas flow also provides two salt‐free windows on a special Pyrex lid so that illumination and observation are possible throughout the growth process. Techniques of the growth procedure and provisions for automatic growth and termination are also described.

ISSN:0034-6748    

DOI:10.1063/1.1717983

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

The vertical and radial betatron oscillation frequencies have been measured on the UCLA 50‐MeV spiral‐ridge cyclotron. The technique used was that of rf knockout, in which the internal beam was passed through a pair of exciter plates which provided an rf electric field. When the frequency was equal to the betatron frequency a detectable increase in betatron oscillation amplitude or ``knockout'' occurred. The knockout as a function of exciter frequency shows a number of resonances rather than a single one. This provides a measurement of radial as well as vertical betatron frequency. Comparisons of the measured frequencies with those calculated from magnetic field measurements are given and show satisfactory agreement.

ISSN:0034-6748    

DOI:10.1063/1.1717984

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

A suggested multistage high voltage multiplier design utilizing a low duty cycle 10‐kc pulse drive has been built, tested, and found reliably operable at twice the dc voltage gain per rectifier stage of conventional sine wave drive Cockcroft‐Walton multipliers. Low capacitance rf tuned circuits across the ends of similarly tuned filament and anode lines permit simultaneous independent utilization of these lines for conveying pulse drive and rf filament heating current. A novel rf compensating and pulse canceling arrangement substantially eliminates output voltage ripple. The ten‐stage prototype tested utilizes miniature commercial 1AX2 vacuum rectifiers and 20‐kV T.V. doorknob condensers and has been successfully operated at output voltages in excess of 250 kV and at output currents exceeding 500 &mgr;A. Output impedance was 60 M&OHgr;. Voltage gains in excess of 200 kV/ft appear feasible.

ISSN:0034-6748    

DOI:10.1063/1.1717985

出版商:AIP    

年代:1962

数据来源: AIP