Planck-HFI activities at CITA

Planck technical description
Home
Technical
Science
Planck@CITA
QLA
Links

Lifetime: 1.5 years

Wavelength coverage: from 25 to 1000 GHz (300 microns to 10 mm).

Launch and orbit: Planck will be launched in 2007 together with ESA's Herschel Space Observatory (formerly called FIRST). The Ariane-5 launcher will inject Planck into a transfer trajectory, and after about four months the satellite will reach its final orbit 1.5 million kilometres away from the Earth. The satellite will circle around the 2nd Lagrangian point of the Earth-Moon-Sun system (or L2 for short), to avoid emission from the Earth, the Moon and the Sun.

Payload: Planck will carry a telescope with a primary mirror of 1.5 meter in size. The telescope will focus radiation from the sky onto the payload, two arrays of highly sensitive detectors called the Low Frequency Instrument (LFI) and the High Frequency Instrument (HFI).

Estimated Planck Instrument Performance Goals
Telescope 1.5 m. (proj. apert.) aplanatic; shared focal plane; $\epsilon_{system}\sim$ 1%
  Viewing direction offset 85o from spin axis; Field of View ~8o
Instrument LFI HFI
Center Frequency (GHz) 30 44 70 100 143 217 353 545 857
Center Wavelength (mm) 10 6.8 4.3 3.0 2.1 1.4 0.85 0.55 0.35
Detector Technology HEMT radio receiver arrays Bolometer arrays
Detector Temperature ~20 K 0.1 K
Cooling Requirements H2 sorption cooler H2 sorption + 4K J-T stage + Dilution
Number of Unpolarised Detectors 0 0 0 4 4 4 4 4 4
Number of Linearly Polarised Detectors 4 6 12 0 8 8 8 0 0
Angular Resolution (arcmin) 33 24 14 9.2 7.1 5.0 5.0 5.0 5.0
Bandwidth (GHz) 6 8.8 14 33 47 72 116 180 283
Average ${\Delta T/T}$$^\dagger$ per pixel$^\ast$ 2.0 2.7 4.7 2.0 2.2 4.8 14.7 147 6700
Average ${\Delta T/T}$* per pixel$^\ast$ 2.8 3.9 6.7   4.2 9.8 29.8    
$^\dagger$ Sensitivity (1$\sigma$) to intensity (Stokes I) fluctuations observed on the sky, in thermodynamic (x10-6) temperature units, relative to the average temperature of the CMB (2.73 K), achievable after two sky surveys (14 months).
$^\ast$ A pixel is a square whose side is the FWHM extent of the beam. Note that these figures are calculated for the average integration time per pixel. In fact the integration time will be very inhomogeneously distributed on the sky and will be much higher in certain regions of it.
* Sensitivity (1$\sigma$) to polarised intensity (Stokes U and Q) fluctuations observed on the sky, in thermodynamic (x10-6) temperature units, relative to the average temperature of the CMB (2.73 K), achievable after two sky surveys (14 months).