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Wide-format CCD systems with high sensitivity in the red spectrum
Two cryostatic digital image recording systems based on wide-format thick-plate
CCD photodetectors CCD231-84 (4128 x 4112 elements) and CCD261-84
(2080 x 4112 elements) (Teledyne E2V, Great Britain) were implemented and
ready for operation at the BTA. The photodetectors are highly sensitive in
the red and near-infrared ranges. In particular, at a wavelength of 900 nm,
the quantum efficiency of the receivers is 60% (CCD231-84) and 90% (CCD261-84),
compared to 30% for the thin CCDs that are currently used in BTA observations.
The DINACON-5 last-generation universal controller is used in CCD systems,
thanks to which a low readout noise (2.3 e–) is achieved, which is 20% better
than the passport specifications. The high sensitivity of photodetectors in
combination with low noise systems makes it possible to obtain more reliable
observation data in the red region of the spectrum and to reduce the exposure
time, which leads to saving the telescope time. The development and production
of systems of this type at SAO RAS are unique in the Russian Federation. The
performed work lays the foundation for the complete update of the BTA-telescope CCDs.
Authors:
Murzin V.A., Ardilanov V.I., Afanasieva I.V., Ivashchenko N.G., Pritychenko M.A.,
Borisenko A.N. (SAO RAS)
Published:
Ardilanov V.I., Murzin V.A., Markelov S.V., Afanasieva I.V., Ivashchenko N.G.,
Mitiani G.Sh., Pritychenko M.A., Borisenko A.N. A new generation CCD controller
for the 6-meter telescope // Astronomy: Cognition Without Borders: Abstracts of
VAK-2017, September 17-22, 2017, Yalta, Crimea, Russia, p. 33.
High-precision and quick alignment of large antenna surfaces
A high-precision method for the quick alignment of large antenna surfaces was
developed and introduced in the standard mode using the example of geodetic
alignment of the Southern sector and the RATAN-600 Flat reflector. The essence
of the method is to fit the software and operating modes of the Leica TDRA6000
tacheometer to the conditions and surface requirements of the RATAN-600 radio
telescope. The advantage of the method is the accuracy (0.5 arcsec, 0.2-0.35
mm in the center and at the edges of the sector, respectively), speed (2-3 hours),
and large-scale measurements (up to 600 m). The method was effectively tested for
the Southern sector and the RATAN-600 Flat reflector in 2019. The figure shows
the measurement scheme of the radio telescope network and the state of some
elements of the Southern sector during alignment. The method is also relevant
for quick assessment of the state of the antenna surface.
Authors:
Zharov V.I., Boyko A.A., Kornienko I.B., Sotnikova Yu.V.
Published:
V. Zharov, Yu. Sotnikova; "Rapid Adjustment of Large Antenna Surfaces
Using Modern Laser Systems"; Ground-Based Astronomy in Russia. 21st Century,
Proceedings of the All-Russian Conference held 21-25 September,
2020 in Nizhny Arkhyz, Russia. Edited by I.I. Romanyuk, I.A. Yakunin,
A.F. Valeev, D.O. Kudryavtsev, 2020, p. 428-431
Development of a technique for applying reflective coatings to multi-purpose
large-sized optical instruments
The results of the method of applying reflective coatings to multi-purpose
large-sized optical instruments are presented. The technique was developed
with reference to the VUAZ-6 vacuum chamber. In order to achieve repeatability
of the result, total redesign of the camera evaporation system was carried out.
Comparative characteristics of the technological processes are given. The results
are presented as functions of the reflection coefficient of the BTA main mirror
surface from the wavelength. We indirectly estimated the thickness of the obtained
layers and their morphology. SAO RAS has the modern vacuum instrument which is
unique in Russia used for applying reflective coatings on objects of various
purposes with a diameter of up to 6 meters.
Authors:
Yakopov G.V.
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