Commission 9: Instruments and Techniques (Instruments Et Techniques)

1988 ◽  
Vol 20 (1) ◽  
pp. 41-54
Author(s):  
C. M. Humphries ◽  
J. Davis ◽  
J. C. Bhattacharyya ◽  
O. Engvold ◽  
B. P. Fort ◽  
...  
Keyword(s):  
Angular Resolution ◽  
High Angular Resolution ◽  
Automatic Instrument ◽  
High Quantum Efficiency ◽  
Large Aperture ◽  
Array Detectors ◽  
Infrared Spectral ◽  
Instrument Control ◽  
Instruments And Techniques ◽  
Made In

The technology leading to very large aperture telescopes and their optics has progressed well in the period since 1984 and plans for many new large aperture telescopes have been made. Focal plane instrumentation continues to become more sophisticated or more efficient: multi-object capabilities, automatic instrument control and operation, and increasing use of CCDs are examples of areas to which this applies. The proportion of time devoted to observations using two-dimensional photoelectronic detectors has grown substantially at many observatories, particularly with telescopes of moderate aperture; and the use of high quantum efficiency array detectors is now being extended into the infrared spectral region. Important advances have also been made in instrumentation and techniques for ground-based high angular resolution interferometry.

scholarly journals Commission No. 9: Instruments and Techniques (Instruments et Techniques)

1988 ◽  
Vol 20 (2) ◽  
pp. 135-149
Author(s):  
C.M. Humphries ◽  
J. Davis
Keyword(s):  
Gamma Ray ◽  
High Angular Resolution ◽  
X Ray ◽  
Stellar Photometry ◽  
Business Meetings ◽  
Array Detectors ◽  
Future Space ◽  
Space Programs ◽  
Resolution Imaging ◽  
Instruments And Techniques

Given here are reports on the scientific and business meetings held in Baltimore involving Commission 9 only. Reports on the following Joint Commission Meetings co-sponsored by Commission 9 (JCM 3 and JCM 6), and on three additional meetings organised jointly with other Commissions, will be found elsewhere in this Volume or in Highlights of Astronomy (Volume 8):-High Angular Resolution Imaging from the Ground (JCM 3)-Stellar Photometry with Array Detectors (JCM 6)-Problems of IR Extinction and Standardization (with Commission 25)-Future Space Programs (with Commission 44)-Gamma-ray, X-ray, Extreme and Far UV, IR and Radio Astronomy from Space (with Commissions 40 and 44)

scholarly journals Commission 9: Instruments and Techniques (Instruments et Techniques)

1991 ◽  
Vol 21 (1) ◽  
pp. 41-52
Author(s):  
John Davis
Keyword(s):  
Adaptive Optics ◽  
Optical Fibers ◽  
Angular Resolution ◽  
New Technology ◽  
High Angular Resolution ◽  
Significant Progress ◽  
Very Large Telescope ◽  
Instruments And Techniques ◽  
Telescope Optics ◽  
New Generation

The period covered by this report has seen significant progress in the development of the new generation of telescopes with apertures in the 8 m plus range. The period has encompassed the major construction phase of the 10 m Keck Telescope, witnessed the commissioning of the European Southern Observatory’s (ESO) New Technology Telescope and the approval of funding for the ESO Very Large Telescope (VLT). Significant progress has been achieved in developing the necessary technology for manufacturing and figuring large mirrors. There have been major expansions of activity in the areas of active control of telescope optics and adaptive optics, and in high angular resolution interferometry with several new groups entering both fields. The use of optical fibers, particularly in the area of multiple-object spectroscopy, has continued to grow. Several telescopes can now be operated remotely and the control systems of new telescopes are being designed to facilitate remote operation.

scholarly journals Infrared Long Baseline Interferometry

1989 ◽  
Vol 8 ◽  
pp. 563-564
Author(s):  
W.C. Danchi ◽  
M. Bester ◽  
P.R. McCullough ◽  
C.H. Townes
Keyword(s):  
Delay Line ◽  
Angular Resolution ◽  
Spectral Characteristics ◽  
High Angular Resolution ◽  
Mid Infrared ◽  
Long Baseline ◽  
Interference Fringes ◽  
Infrared Spectral ◽  
New Instruments ◽  
Hgcdte Photodiodes

During the last few years, two new instruments using long baseline interferometry have been constructed for high angular resolution astronomy in the mid-infrared spectral region (8-12 μxm). One called SOIRDETE-Synthese d’Overture en InfraRouge a DEux TElescopes-was built by J. Gay and his collaborators at CERGA. SOIRDETE has a fixed E-W 15 m baseline and two 1 m diameter telescopes of conventional design. This instrument obtains interference fringes by adjusting an optical-precision delay line in discrete steps to compensate for the geometrical delay of the projected baseline. The interference fringe from the source is detected using HgCdTe photodiodes. Because the instrumental delay has discrete steps a time-domain interferogram is created. This interferogram, upon Fourier transformation to the frequency domain, yields information about the spectral characteristics of the source. First fringes have recently been obtained with this instrument (Gay, 1988).

Millimeter-wave interferometry of Proto-Planetary Nebulae

1997 ◽  
Vol 180 ◽  
pp. 346-346
Author(s):  
A. Dayal ◽  
J. H. Bieging ◽  
P. Bergman
Keyword(s):  
Radiative Transfer ◽  
Millimeter Wave ◽  
Loss Rate ◽  
Angular Resolution ◽  
Mass Loss Rate ◽  
High Angular Resolution ◽  
Molecular Gas ◽  
Owens Valley ◽  
Physical Conditions ◽  
Made In

We have observed 2 compact PPNe, AFGL 2343 and IRAS 22272+5435, in the CO J=1-0 transition using the Owens Valley interferometer (OVRO), and the NRAO 12-meter telescope. Our observations were made in the low and intermediate resolution configurations of the interferometer and we obtain a synthesized beam (HPBW) of ≃ 4″. We are now modelling both sources using statistical equilibrium/radiative transfer codes. Our objectives are to a) map the distribution and kinematics of the molecular gas at high angular resolution and b) estimate the physical conditions (mass loss rate, temperature, density) in the molecular envelopes, through our models.

Small-Angle Electron Scattering (SAES) of Polymers

1985 ◽  
Vol 43 ◽  
pp. 78-79
Author(s):  
Ralph Oralor ◽  
Pamela Lloyd ◽  
Satish Kumar ◽  
W. W. Adams
Keyword(s):  
Electron Scattering ◽  
Small Angle ◽  
Angular Resolution ◽  
Structural Features ◽  
Objective Lens ◽  
High Angular Resolution ◽  
Push Button ◽  
First Case ◽  
Diffraction Mode ◽  
Very High

Small angle electron scattering (SAES) has been used to study structural features of up to several thousand angstroms in polymers, as well as in metals. SAES may be done either in (a) long camera mode by switching off the objective lens current or in (b) selected area diffraction mode. In the first case very high camera lengths (up to 7Ø meters on JEOL 1Ø ØCX) and high angular resolution can be obtained, while in the second case smaller camera lengths (approximately up to 3.6 meters on JEOL 1Ø ØCX) and lower angular resolution is obtainable. We conducted our SAES studies on JEOL 1ØØCX which can be switched to either mode with a push button as a standard feature.

Large-angle convergent-beam electron-diffraction study of coherent precipitates and decorated dislocations

1996 ◽  
Vol 54 ◽  
pp. 1002-1004
Author(s):  
J.M.K. Wiezorek ◽  
H.L. Fraser
Keyword(s):  
Electron Diffraction ◽  
Angular Resolution ◽  
Large Angle ◽  
Electron Diffraction Study ◽  
Convergent Beam Electron Diffraction ◽  
Crystal Defects ◽  
High Angular Resolution ◽  
Beam Electron ◽  
Diffraction Plane ◽  
Convergent Beam

Conventional methods of convergent beam electron diffraction (CBED) use a fully converged probe focused on the specimen in the object plane resulting in the formation of a CBED pattern in the diffraction plane. Large angle CBED (LACBED) uses a converged but defocused probe resulting in the formation of ‘shadow images’ of the illuminated sample area in the diffraction plane. Hence, low-spatial resolution image information and high-angular resolution diffraction information are superimposed in LACBED patterns which enables the simultaneous observation of crystal defects and their effect on the diffraction pattern. In recent years LACBED has been used successfully for the investigation of a variety of crystal defects, such as stacking faults, interfaces and dislocations. In this paper the contrast from coherent precipitates and decorated dislocations in LACBED patterns has been investigated. Computer simulated LACBED contrast from decorated dislocations and coherent precipitates is compared with experimental observations.

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