Clover (telescope)
Encyclopedia
Clover would have been an experiment to measure the polarization of the Cosmic Microwave Background. It was approved for funding in late 2004, with the aim of having the full telescope operational by 2009. The project was jointly run by Cardiff University
, Oxford University, the Cavendish Astrophysics Group
and the University of Manchester
.
The Clover Project was meant to consist of two independent telescopes, one operating at 95 GHz
with the other operating at both 150 and 225 GHz
. Both telescopes were to be sited near the CBI
site in the Atacama Desert, Chile. The two telescope receivers
would have been large format focal plane arrays of either 100 or 200 bolometric detectors
.
The aim of the experiment was to measure the B-mode polarization of the Cosmic Microwave Background between multipoles of 20 and 1000 down to a sensitivity limited by the foreground contamination due to lensing
. This would have allowed the detection of primordial gravitational waves in the universe so long as the ratio of scalar perturbations (caused by density fluctuations in the early universe) to the tensor perturbations caused by gravitational waves was greater than
.
It was hoped that the telescope would have spent around 2 years observing a total of around 1,000 degree
s of sky, made up of several patches of sky where polarized foregrounds (synchrotron
and thermal dust emission) are at a minimum.
Clover was canceled in March 2009 as STFC were unable to provide the requested additional funds of 2.55 million pounds to finish the project.
Cardiff University
Cardiff University is a leading research university located in the Cathays Park area of Cardiff, Wales, United Kingdom. It received its Royal charter in 1883 and is a member of the Russell Group of Universities. The university is consistently recognised as providing high quality research-based...
, Oxford University, the Cavendish Astrophysics Group
Cavendish Astrophysics Group
The Cavendish Astrophysics Group is based at the Cavendish Laboratory at the University of Cambridge. The group operates all of the telescopes at the Mullard Radio Astronomy Observatory except for the 32m MERLIN telescope, which is operated by Jodrell Bank.The group is the second largest of three...
and the University of Manchester
University of Manchester
The University of Manchester is a public research university located in Manchester, United Kingdom. It is a "red brick" university and a member of the Russell Group of research-intensive British universities and the N8 Group...
.
The Clover Project was meant to consist of two independent telescopes, one operating at 95 GHz
Hertz
The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....
with the other operating at both 150 and 225 GHz
Hertz
The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....
. Both telescopes were to be sited near the CBI
Cosmic Background Imager
The Cosmic Background Imager was a 13-element interferometer perched at an elevation of 5,080 metres at Llano de Chajnantor Observatory in the Chilean Andes...
site in the Atacama Desert, Chile. The two telescope receivers
Receiver (radio)
A radio receiver converts signals from a radio antenna to a usable form. It uses electronic filters to separate a wanted radio frequency signal from all other signals, the electronic amplifier increases the level suitable for further processing, and finally recovers the desired information through...
would have been large format focal plane arrays of either 100 or 200 bolometric detectors
Bolometer
A bolometer is a device for measuring the power of incident electromagnetic radiation via the heating of a material with a temperature-dependent electrical resistance. It was invented in 1878 by the American astronomer Samuel Pierpont Langley...
.
The aim of the experiment was to measure the B-mode polarization of the Cosmic Microwave Background between multipoles of 20 and 1000 down to a sensitivity limited by the foreground contamination due to lensing
Gravitational lens
A gravitational lens refers to a distribution of matter between a distant source and an observer, that is capable of bending the light from the source, as it travels towards the observer...
. This would have allowed the detection of primordial gravitational waves in the universe so long as the ratio of scalar perturbations (caused by density fluctuations in the early universe) to the tensor perturbations caused by gravitational waves was greater than
.It was hoped that the telescope would have spent around 2 years observing a total of around 1,000 degree
Degree (angle)
A degree , usually denoted by ° , is a measurement of plane angle, representing 1⁄360 of a full rotation; one degree is equivalent to π/180 radians...
s of sky, made up of several patches of sky where polarized foregrounds (synchrotron
Synchrotron
A synchrotron is a particular type of cyclic particle accelerator in which the magnetic field and the electric field are carefully synchronised with the travelling particle beam. The proton synchrotron was originally conceived by Sir Marcus Oliphant...
and thermal dust emission) are at a minimum.
Clover was canceled in March 2009 as STFC were unable to provide the requested additional funds of 2.55 million pounds to finish the project.