QUaD (QUEST at DASI)

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QUaD (QUEST at DASI)

• Expeiment to be fielded at the South Pole in late
  2004
• Specifically designed to measure both E and B
  mode polarization

Stanford (US PI Institution) Focal plane design
and assembly Warm and cold electronics Integration
and testing
Cardiff (UK PI Institution) Telescope design and
assembly Cryostat and fridge Filters and optical
components
U. Chicago Telescope mount and software
JPL/Caltech/IPAC Bolometers Cold JFETs Software
Maynooth College, Ireland Optics design and
testing
University of Edinburgh, UK Software and science
definition
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QUaD Science Goals

• To map CMB polarization on angular scales gt 4?
• Optimized to map E-modes, and B-modes produced by
  gravitational lensing and gravity waves

The QUaD telescope was installed on the DASI
mount in the 2003-4 season
The largest scales will be determined by the scan
strategy
Planned l-space coverage of QUaD
The smallest scales are determined by the angular
resolution of the experiment
Hu et al. 2002
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The QUaD Receiver
Focal plane at 250 mK
Load resistors
Bolometers
Corrugated feed
metal-mesh resonant grid filters define the band
JFETs at 4K
Freq (GHz) Beam (arcmin) No. feeds
100 6.3 12
150 4.2 19
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Why the South Pole?

• Very low precipitable water vapor
• Very stable thermal environment (1 day and 1
  night)
• Ability to view the same area of sky continuously
• Existing facilities (DASI mount)

Required Facilities

• Liquid cryogens ( 500l/month)
• Machining facilities for instrument
  adjustments/fixes
• Data transfer (1-2 Gbyte of data produced every
  day)
• Some machinist time

Other Shared Facilities?

• Beam measuring?