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Cumings, N. P.

Publications and source records attributed to Cumings, N. P..

10 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1986

Advanced X-ray Astrophysics Facility (AXAF) instrumentation

The instrumentation planned for the Advanced X-ray Astrophysics Facility (AXAF), a space-based observation platform for the 1990s, is described. The AXAF will feature a grazing incidence telescope at the end of the observatory and four independently selected instruments at the other end, including: a CCD imaging spectrometer; a Bragg crystal spectrometer; and two transmission grating spectrometers located directly behind the telescope to detect first order spectral images. The instruments are currently in the definition phase to be followed by design and development starting in the late 1980s. A detailed schematic diagram of the Bragg crystal imaging spectrometer is provided.

Winkler, C. E.↗
NASA NTRS1985

The Extended Range X-Ray Telescope center director's discretionary fund report

An Extended Range X-Ray Telescope (ERXRT) of high sensitivity and spatial resolution capable of functioning over a broad region of the X-ray/XUV portion of the spectrum has been designed and analyzed. This system has been configured around the glancing-incidence Wolter Type I X-ray mirror system which was flown on the Skylab Apollo Telescope Mount as ATM Experiment S-056. Enhanced sensitivity over a vastly broader spectral range can be realized by the utilization of a thinned, back-illuminated, buried-channel Charge Coupled Device (CCD) as the X-ray/XUV detector rather than photographic film. However, to maintain the high spatial resolution inherent in the X-ray optics when a CCD of 30 micron pixel size is used, it is necessary to increase the telescope plate scale. This can be accomplished by use of a glancing-incidence X-ray microscope to enlarge and re-focus the primary image onto the focal surface of the CCD.

Hoover, R. B.↗
NASA NTRS1985

Advanced X-ray Astrophysics Facility (AXAF) science instrumentation

AXAF is to be equipped with a high performance X-ray telescope for the conduction of detailed astrophysics research. The observatory is to be serviced by the Space Station or the Shuttle, depending on capabilities during the AXAF operational period. The AXAF is to utilize the wavelength band from 1.2 A to 120 A. Attention is given to the AXAF science team, the AXAF observatory characteristics, the AXAF science instrument definition program, the Advanced Charge Coupled Device (CCD) Imaging Spectrometer (ACIS), the High Resolution Camera (HRC), the Bragg Crystal Spectrometer (BCS), the X-ray Spectrometer (XRS), the transmission gratings, and the program schedule.

Dailey, C. C.↗
NASA NTRS1984

The new MSFC Solar vector magnetograph. Center director's discretionary fund

The unique MSFC solar vector magnetograph allows measurements of all three components of the Sun's photospheric magnetic field over a wide field-of-view with spatial resolution determined by a 2.7 x 2.7 arc second pixel size. This system underwent extensive modifications to improve its sensitivity and temporal response. The modifications included replacing an SEC vidicon detector with a solid-state CCD camera; replacing the original digital logic circuitry with an electronic controller and a computer to provide complete, programmable control over the entire operation of the magnetograph; and installing a new polarimeter which consists of a single electro-optical modulator coupled with interchangeable waveplates mounted on a rotating assembly. The system is described and results of calibrations and tests are presented. Initial observations of solar magnetic fields with the new magnetograph are presented.

Hagyard, M. J.↗
NASA NTRS1983

Image motion compensation by area correlation and centroid tracking of solar surface features

An experimental solar correlation tracker was tested and evaluated on a ground-based solar magnetograph. Using sunspots as fixed targets, tracking error signals were derived by which the telescope image was stabilized against wind induced perturbations. Two methods of stabilization were investigated; mechanical stabilization of the image by controlled two-axes motion of an active optical element in the telescope beam, and electronic stabilization by biasing of the electron scan in the recording camera. Both approaches have demonstrated telescope stability of about 0.6 arc sec under random perturbations which can cause the unstabilized image to move up to 120 arc sec at frequencies up to 30 Hz.

Nein, M. E.↗
NASA NTRS1981

The MSFC vector magnetograph

The NASA/Marshall Space Flight Center's solar vector magnetograph system allows measurements of all components of the Sun's photospheric magnetic field over a 5 x 5 or 2.5 x 2.5 arc min square field of view with an optimum time resolution of approximately 100 sec and an optimum signal-to-noise of approximately 1000. The basic system components are described, including the optics, detector, digital system, and associated electronics. Automatic sequencing and control functions are outlined as well as manual selections of system parameters which afford unique system flexibility. Results of system calibration and performance are presented, including linearity, dynamic range, uniformity, spatial and spectral resolutions, signal-to-noise, electro-optical retardation and polarization calibration.

Hagyard, M. J.↗
NASA NTRS1977

The spiral configuration of sunspot magnetic fields

Distributions of circularly and linearly polarized intensities are computed using an analytical magnetic field model for an isolated sunspot, and these intensity distributions are compared with observed intensities in all Stokes parameters in the 5250-A line measured with the Marshall Space Flight Center's vector magnetograph. The qualitative agreement between measured and calculated linearly polarized intensity distributions is discussed with regard to implications as to the configuration of the transverse magnetic field of the isolated sunspot.

Hagyard, M. J.↗
NASA NTRS1975

Real time solar magnetograph Skylab mission Atlas

An atlas of all magnetic field observations made during the Skylab missions with the Real Time Solar Magnetograph system located at the Marshall Space Flight Center is presented. Also included are a description of the system and its operation; an outline of the data reductions performed; and a discussion of probable errors, noise, magnetic sensitivity, and system reliability.

Hagyard, M. J.↗
NASA NTRS1973

Measurements of the performance of multiwire proportional chambers

Data are presented that may be useful in formulating engineering specifications and test procedures for the proportional counter hodoscope to be flown as part of the High Energy Cosmic Ray Experiment on the High Energy Astronomy Observatory (HEAO), Mission A. A collection of preliminary data taken in laboratory tests of multiwire counters with an anode wire spacing of 5 mm and cathode gap spacing of 1 cm is presented. The data are from laboratory development models or counters for balloon flights and were selected to illustrate several aspects of proper and improper counter performance. Most of the data were taken from a large proportional counter hodoscope which has an active area of 0.5 by 0.5 m and 104 wires per plane.

Austin, R. W.↗