About CHAMP+

CHAMP+ is a dual-frequency heterodyne submillimeter array receiver built jointly by MPIfR and NOVA/SRON/DIMES for APEX. The mixer elements are developed and built at SRON and will ship to Bonn in the first half of 2004 for integration into the array. CHAMP+ will ship to Chajnantor in the second half of 2004 and be commissioned in 2005. The Netherlands astronomical community will have access to 42 24-hour observing days in the period of 2005-2010. CHAMP+ will be essential for the spectroscopic exploration of the 'warm' molecular Universe.

CHAMP+ Specifications (from proposal)
Telescope APEX
Location Llano de Chajnantor
Elevation 5000 m
Telescope Diameter 12 m
Low-frequency band
Number of pixels 7 beams + 1 spare
Array configuration 2:3:2
RF range 602-720 GHz (ALMA band 9)
Beam size 9-7 arcsec
Mixer DSB noise temperature <150-200 K
Expected Tsys 1000-1500 K
IF 2 GHz in the 4-8 GHz band
IF pass-band ripple <3dB / 2 GHz
Polarization purity >95%
Beam efficiency >90% (Gaussian beam efficiency)
High-frequency band
Number of pixels 7 beams + 1 spare
Array configuration 2:3:2
RF range 790-950 GHz (ALMA band 10; large overlap HIFI band 3)
Beam size 7-6 arcsec
Mixer DSB noise temperature <350-400 K
Expected Tsys 1800-2500 K
IF 2 GHz in the 4-8 GHz band
IF pass-band ripple <3dB / 2 GHz
Polarization purity >95%
Beam efficiency >90% (Gaussian beam efficiency)

Estimated sensitivity of a single pixel in a 2 MHz channel (1 km s-1: appropriate for galactic astronomy) after 20 min of integration: 40-60 mK at 602-720 GHz and 75-105 mK at 790-950 GHz. In a 40 MHz channel (20 km s-1: for extra-galactic astronomy) after 1 hour of integration: 5-8 mK at 602-720 GHz and 9-13 mK at 790-950 GHz.