Colloq Abstract - Sivasankaran
September 30
11am Mountain
Srikanth Sivasankaran
Telescope Optics Design - Parameters and Options
Abstract
NRAO is busy fine tuning the science drivers and array configuration for the Next Generation Very Large Array (ngVla). On the technical front, receiver bands and antenna geometry are being critically discussed to arrive at a viable solution to fulfill the scientific goals of the ngVLA. Dual-offset reflector geometry, similar to the GBT, is the default choice for the antenna. This geometry offers sufficient real estate for locating the number of receivers that are required to cover the specified 10-115 GHz range, in addition to the option of going down to 1.2 GHz. However, unlike the GBT, the feed/secondary reflector support structure needs to be located closer to the ground for ease of servicing of the receivers. This colloquium talk will cover the effect of certain optics parameters on the size and location of the feed/subreflector, shaped reflector system and possible geometries of dual-offset reflectors. A few examples of 18-meter antennas with performance comparisons will also be discussed.
