ASIAA AMiBA, The Array for Microwave Background Anisotropy
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Instrumentation Overview

The telescope is a coplanar, radio interferometric array sitting on top of a hexapod mount. Currently, the the array is consisted with 7 elements of radio antennas operating at 94 GHz and 12 GHz bandwidth. The antenna size is 60 cm in diameter, and they will be replaced with larger dishes of 1.2 meter in our next phase of operation. To process the large bandwidth, the correlator is an analog-type, lag correlator. All the antennas, electronics, and mechanical components are located on a carbon fiber reinforced plastic (CFRP) platform, and supported by the hexapod mount. As shown in the photo above, the Array is in its close-pack configuration. All the seven antennas congregate at the center of the platform. Each antenna is covered with GoreTex fabric sheet to protect potential damage in the antenna from accidental pointing too close to the Sun. The hexagonal shape structure is the CFRP platform. It has dimensions of roughly 6 meter in diameter. The platform is supported at from below by six jackscrews, which form the base of a hexapod. The following table list the key specifications of the telescope.

Click on the image to open the larger image

The first phase comprised of seven 0.6m antennas, with scientific observations 2007 - 2008.

The second phase expanded the array to thirteen 1.2m antennas, enhancing the ability to detect clusters at higher redshifts.

AMiBA Characteristics/Performance

Frequency range RF: 86 – 102 GHz
IF: 2 – 18 GHz
Effective bandwidth 10 GHz
Receivers Dual polarization HEMT LNA, cooled to 15 K
System temperature 85 K
Correlator XX* & YY* (switchable to
XY* & YX*)
Efficiency Antenna: ~ 0.6
Total: ~ 0.4
  AMiBA-7 AMiBA-13
Number of antenna // baseline 7 // 21 13 // 78
Antenna diameter 0.6 m 1.2 m
Primary beam FWHM 23' 11.5'
Synthesized beam FWHM (close packed configuration) 6' 2.5'
Point source sensitivity (for 1 hr on-source integration) 65 mJy/beam 8 mJy/beam
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