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Results for “PHOTOMULTIPLIER”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Photomultiplier blanking circuit

Circuit for protecting photomultiplier equipment from current surges which occur when exposed to brilliant illumination is discussed. Components of circuit and details of operation are provided. Circuit diagram to show action of blanking pulse on zener diode is included.

Mcclenahan, J. O.↗
NASA NTRS1975

Color-coded area sensitivity maps of photomultipliers

Technique was devised specifically for testing photomultipliers and other photodetectors, but it could also be used to color code any type of mapping data, such as weather or topographical maps, thermal or pressure distributions on reentry surfaces, or any other three-dimensional data to be displayed in two-dimensional form.

Youngbluth, O., Jr.↗
NASA NTRS1974

Photomultiplier circuit including means for rapidly reducing the sensitivity thereof

A simple, reliable and inexpensive control circuit is described for rapidly reducing the bias voltage across one or more of the dynode stages of a photomultiplier, to substantially decrease its sensitivity to incoming light at those times where excess light intensity might damage the tube. The control circuit comprises a switching device, such as a silicon controlled rectifier (SCR), coupled between a pair of the electrodes in the tube, preferably the cathode and first dynode, or the first and second dynodes, the switching device operating in response to a trigger pulse applied to its gate to short circuit the two electrodes. To insure the desired reduction in sensitivity, two switching stages, the devices be employed between two of the electrode stages, the devices being operated simultaneously to short circuit both stages.

Mcclenahan, J. O.↗
NASA NTRS1974

Photomultiplier tube reliability study for the HEAO program

Results concerning the research on photomultiplier tubes required for the HEAO program are reported. The general specifications are discussed for providing a series of tests for helping the operational reliability of its application, and for permitting comparison of performance of similar types, from various manufacturers.

Richardson, C.↗
NASA NTRS1973

Single photon detection and sub-nanosecond timing resolution with RCA C31034 photomultiplier

The very high quantum efficiencies and low dark count rates achieved with selected RCA C31034 photomultipliers make them attractive candidates for single photoelectron fast timing experiments. Single photoelectron plateau counting and a timing resolution of 0.60 nsec (FWHM) were obtained using fast amplifiers, constant fraction timing discriminators, and a pulsed light emitting diode. A redesign of the C31034 incorporating features of the very fast C31024 is suggested to yield even better timing resolution.

Reisse, R.↗
NASA NTRS1975

Testing the linearity of response of gated photomultipliers in wide dynamic range laser radar systems

Laser radar data acquisition systems have been utilized in conjunction with a light emitting diode to evaluate photomultipliers for laser radar use. Light pulses with an exponential decay rate of approximately one decade per sixty microseconds, as well as other pulse shapes, were used to drive the tubes. Properties studied in the analog mode include nonlinearity at high output currents, transient behavior upon gating, gate holdoff, dynamic range limitations because of light-induced noise, and the effect of dynode gating on tubes without a focus grid. Some of these properties were also studied in the photon counting mode, along with single photoelectron pulse shape and afterpulsing. A brief description of the laser radar technique of atmospheric measurements is included.

Hunt, W. H.↗
NASA NTRS1976

Effects of 1- and 2-MeV electrons on photomultiplier tubes

Various types of photomultiplier tubes useful for space applications were irradiated with 1- and 2-MeV electrons at Van Allen radiation belt fluxes of 100,000 to 10 millions electrons/sq cm-sec. The increase in the dark current due to electron irradiation was observed at various bias voltages under worst-case conditions (no shielding). Results were presented in the form of dark current plotted against electron flux. All the tubes tested showed extremely large increases in dark current. Tube types 541A, 6217, 6199, and 6903 exhibited the largest increases under irradiation, whereas type 1P22 was affected the least. All the damage observed was transient. The luminescence produced in the optical window probably accounts for a large part of the dark-current increases, but there were some effects possibly due to direct irradiation of the photocathode and dynode chain.

Beatty, M. E., III↗