Solar-blind photoelectric detection systems for satellite applications
Open magnetic electron multipliers /MEM/ with continuous dynode and field strips for satellite- borne detection systems, emphasizing extreme UV detectors
Huber, M. C. E.↗
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Results for “ELECTRON MULTIPLIER”
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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AC power meter
AC power meters using electronic multiplier for overcoming limitations concerning frequency ranges, response times, power factor and distortion
Vrancik, J. E.↗
A versatile pulse amplifier
Versatile pulse amplifier for use with scintillation counters, surface barrier detectors, proportional counters or channel electron multipliers
Lampton, M.↗
Lunar mass spectrometer test program
The procedures used and the results are described, which were obtained in a test program to demonstrate the performance of a candidate lunar mass spectrometer. The instrument was designed to sample and measure gases believed to exist in the lunar atmosphere at the surface. The instrument consists of a cold cathode ion source, a small quadrupole mass analyzer, and an off-axis electron multiplier ion-counting detector. Instrument resolution, sensitivity, and S/N ratio were demonstrated over the mass range 0-150 amu and over a partial pressure range from ntorr to ptorr. The subject analyzer was also prepared for extended testing, in conjunction with two other candidate instruments, in a large molecular beam vacuum facility.
Torney, F. L.↗
Wind tunnel mass spectrometer design study
The sampling probe to measure the free stream gas composition in a hypersonic wind tunnel is described. Using a free expansion of the continuum flow, a series of sampling inlet-pumping stages is evaluated. Mass analysis is carried out with a quadrupole mass spectrometer employing a crossed electron beam, molecular beam ion source, and an off-axis electron multiplier. The spatial distribution of the sampled molecular flux and the pumping requirements are evaluated for varying inlet conditions of gas density and flow velocity. The signal-to-noise ratio of the molecular beam formed by this series of coaxial inlets is also determined. The signal-to-noise ratio of the unscattered flux is sufficiently high that an unambiguous determination of the beam composition and of the free stream gas properties can be made. The magnitude of the detected signal is sufficiently high that measurement of trace constituents two orders of magnitude below the primary beam signal can be made.
Hueser, J. E.↗
Lunar mass spectrometer test program
The procedures are described along with results obtained in a test program conducted to demonstrate the performance of a candidate lunar mass spectrometer. The instrument was designed to sample and measure gases believed to exist in the lunar atmosphere at the surface. The subject instrument consists of a cold cathode ion source, a small quadrupole mass analyzer and an off axis electron multiplier ion counting detector. The major program emphasis was placed on demonstrating instrument resolution, sensitivity and S/N ratio over the mass range 0-150 amu and over a partial pressure range from 10 to the minus 9th power to 10 to the minus 13th power torr. Ultrahigh vacuum tests were conducted and the minimum detectable partial pressure for neon, argon, krypton and xenon was successfully determined for the spectrometer using isotopes of these gases. With the exception of neon, the minimum detectable partial pressure is approximately 4 x 10 to the minus 14th power torr for the above gases.
Torney, F. L.↗
Multispectral image dissector camera system
A sensor system which provides registered high-solution multispectral images from a single sensor with no mechanical moving parts is reported, and the operation of an image dissector camera (IDC) is described. An earth scene 100 nautical miles wide is imaged through a single lens onto a photocathode surface containing three spectral filters, thereby producing three separate spectral signatures on the photocathode surface. An electron image is formed, accelerated, focused, and electromagnetically, deflected across an image plane which contains three sampling apertures, behind which are located three electron multipliers. The IDC system uses electromagnetic deflection for cross-track scanning and spacecraft orbit motion for along-track scanning, thus eliminating the need for a mechanical scanning mirror.
Johnson, B. L.↗
Observations of Interchange Between Acceleration and Thermalization Processes in Auroral Electrons
The results of high time-resolution measurements of energetic electrons in an auroral break up are presented. Electrons with energies from 500 eV to over 100 keV and pitch angles from 0 to 150 deg were detected with two detectors onboard sounding rocket 18:63 UE. Complete energy spectra were taken every 0.1 seconds. The procedure for cleaning and activating the BeCu dynodes of a small, rugged, high gain electron multiplier is described. A theoretical study of the energy-angular response of a spherical plate electrostatic analyzer is compared to experimental results. An energy spectrum unfolding technique which does not require the assumption of a histogram-type energy spectrum is presented. A method of determining sounding rocket orientation from the output of a single magnetometer is described.
Pongratz, M. B.↗
Detection of crystals in CO2 jet plumes.
It is shown that the electron diffraction technique is well suited for studying condensation effects in low-density flows. The possibility of improving the sensitivity and resolution of the detector by using electron multipliers and by increasing the slit distance is examined.
Beylich, A. E.↗
An extreme ultraviolet photometer for solar observations from the Atmosphere Explorer satellites
A broadband photometer experiment is being fabricated for the Atmosphere Explorer C, D and E missions to record the solar irradiance in the 40 to 1250 A region with seven distinct passbands. The experiment consists principally of four spinal electron multipliers located behind a moving eight position filter wheel. Six metallic filters are used to spectrally isolate the solar irradiance. In addition three Al2O3 diodes, two with filters, are being used to record the solar irradiance over the range of orbital altitudes from perigee through apogee. A principal goal of the experiment will be to measure time dependence of the solar irradiance with respect to a storage ring synchrotron light source which has been calibrated in terms of the best currently available standards of irradiance.
Heath, D. F.↗
Design, fabrication, assembly and delivery of a laboratory prototype of a residual gas analyzer
The design, development, and testing of a wide mass range residual gas analyzer which will be one component of an integrated real time contamination monitor system are described. The instrument has been developed and tested to the laboratory prototype phase, demonstrating the performance that can be expected from a flight instrument of similar design. The instrument's analyzer is of the quadrupole type and a cold cathode ion source is employed as the ionizer. The associated electronics supply all necessary operating and mass sweep voltages for the ionizer, analyzer and electron multiplier ion detector. The instrument features a very fast linear electrometer with automatic range changing. The full mass range of 2 to 300 amu is automatically and repetitively scanned every sixty seconds and suitable telemetry outputs are provided for intensity and mass identification as well as a digital identification of the electrometer range.
Kreisman, W. S.↗
Use of MgF2 and LiF photocathodes in the extreme ultraviolet.
The photoelectric yields of 2000-A thick samples of MgF2 and LiF have been measured at wavelengths in the range from 1216 to 461 A. Peak values of 43 and 34%, respectively, were obtained at wavelengths around 550 A at 45 deg incidence. Coating the cathode of a channel electron multiplier with 3000 A of MgF2 produced no significant deterioration in the electrical properties and increased the sensitivity by factors of 1.62, 2.76, and 2.60 at wavelengths of 742, 584, and 461 A, respectively. Since the stability of response of the MgF2 photocathodes appears to be equal to that of conventional metallic and semiconducting cathodes, it is concluded that MgF2 would be a practical, high-efficiency photocathode for use in the extreme ultraviolet.
Lapson, L. B.↗
Nuclear Science Symposium, 19th, and Nuclear Power Systems Symposium, 4th, Miami, Fla., December 6-8, 1972, Proceedings.
Major topics covered include radiation monitoring instrumentation, nuclear circuits and systems, biomedical applications of nuclear radiation in diagnosis and therapy, plasma research for fusion power, reactor control and instrumentation, nuclear power standards, and applications of digital computers in nuclear power plants. Systems and devices for space applications are described, including the Apollo alpha spectrometer, a position sensitive detection system for UV and X-ray photons, a 4500-volt electron multiplier bias supply for satellite use, spark chamber systems, proportional counters, and other devices. Individual items are announced in this issue.
Source record↗
A neutral-atmosphere composition experiment for the Atmosphere Explorer-C, -D, and -E.
The neutral-atmosphere composition experiment instrumentation is designed to obtain in-situ measurements of neutral thermosphere composition from Atmosphere Explorer-C, -D, and -E. The system is based on previously flown OGO-6 and San Marco-3 composition instruments. The mass-spectrometer sensor includes a gold-plated thermalizing chamber and ion source, a hyperbolic rod quadrupole analyzer, and an off-axis electron multiplier. Automatic ion-source sensitivity control and pulse-counting techniques provide density measurement capability from approximately 125 to 1000 km altitude. The normal operating mode includes measurement at all masses in the range of 1 to 44 amu, with emphasis on hydrogen, helium, oxygen, nitrogen, and argon.
Pelz, D. T.↗
An extreme UV photometer for solar observations from Atmosphere Explorer.
A broadband photometer experiment is being prepared for the Atmosphere Explorer-C, -D, and -E missions to record the solar irradiance in seven wavelength bands in the range from 40 to 1250 A. The experiment contains four spiral electron multipliers located behind a moving eight-position filter wheel. Six of the eight sections of this wheel contain metallic filters used to spectrally isolate the solar irradiance. In addition, three Al2O3 diodes, two with filters, are being used to record the solar irradiance over the full range of orbital altitudes including those at which operation of multipliers with high voltages on open structures would be unsafe. A principal goal of the experiment will be to measure time dependence of the solar irradiance.
Heath, D. F.↗
Photon counting with a self-scanned diode array.
A self-scanned diode array may be used as temporary storage for individual photons if enough gain is provided by an image intensifier or electron multiplier to provide a detectable signal from each input event.
Mcnall, J. F.↗
Preliminary results with saturable microchannel array plates
Microchannel array plates with a performance comparable to that of a conventional channel electron multiplier have been obtained for the first time. These array plates employ an angled electrostatic field to inhibit the feedback of positive ions within the microchannels. Saturated output pulse height distributions with modal gain values in excess of 10 million have been obtained and stable operation demonstrated over a range of ambient pressures from 0.0000001 to 0.00008 torr. However, a time-dependent reduction in the gain has been observed with these experimental plates because of the accumulation of charge on the insulating strips which are inserted in the wall of the microchannel to establish the angled electrostatic field.
Timothy, J. G.↗
Electro-optical detector to improve sensitivity of a focal-plane mass spectrometer
Wedge-shaped microchannel electron multiplier array has been proposed to improve sensitivity of focal-plane mass spectrometer by two to four orders of magnitude.
Giffin, C. E.↗