September 28th 2007 Focal Plane Array Discussion Meeting

Overview

The GBT is a superb telescope with excellent performance at frequencies up to 50 GHz (wavelength = 7mm). Demand for telescope time at the higher frequencies exceeds supply by a factor of > 5. All indications are that 90GHz (3mm) operation is well within our grasp. However, the telescope is still only equipped with single or dual-feed receivers, restricting its instantaneous sky coverage. Development of array receivers at a range of frequencies would truly revolutionize the capabilities of the telescope.

We propose two parallel paths to develop the focal plane array program, starting immediately:

• Study the science drivers, explore technical options, develop collaborations with interested groups, and identify funding for a complete focal plane array development program. This would include ~100 pixel array receivers (nominally at K and W-band), a new, digital, IF transmission system, advanced Spectrometers, and full data analysis software.

• In parallel, start work on a pathfinder 7-pixel K-band (18-26GHz) focal plane array, the necessary first step in the full program and a powerful scientific instrument in its own right. This array would initially be used with the existing GBT IF system and Spectrometer.

The goals of the 28th September 2007 meeting are to continue discussion of the science drivers for focal plane arrays on the GBT, and to review the arguments which lead us to propose K-band as the frequency for the pathfinder array. As an outcome of the meeting, we seek approval to initiate development of the K-band array.

Agenda

• 09:00 – 09:15 Introduction (Richard Prestage)
• 09:15 – 10:15 Science Drivers
  • General Overview (Jay Lockman)
  • W-band Science Drivers (Juergen Ott)
  • K-band Science Drivers (Juergen Ott)
• 10:15 – 10:30 Break
• 10:30 – 11:00 Technical considerations for an FPA Program (Steve White)
• 11:00 – 11:30 The K-band FPA Proposal (Matt Morgan)
• 11:30 – noon General Discussion, Summary

Material

• Purpose and Agenda for meeting
• K-band Science Case
• W-band Science Case
• Focal Plane Array Program - Overview (Powerpoint Version)
• K-band Focal Plane Array Technical Proposal
• K-band Focal Plane Array Presentation (Powerpoint Version)