CAST: A search for solar axions at CERN (original) (raw)

Search for solar axions: the CAST experiment at CERN

2006

a Deceased Hypothetical axion-like particles with a two-photon interaction would be produced in the sun by the Primakoff process. In a laboratory magnetic field they would be transformed into Xrays with energies of a few keV. The CAST experiment at CERN is using a decommissioned LHC magnet as an axion helioscope in order to search for these axion-like particles. The analysis of the 2003 data 1 has shown no signal above the background, thus implying an upper limit to the axion-photon coupling of gaγ < 1.16 × 10 −10 GeV −1 at 95% CL for ma 0.02 eV. The stable operation of the experiment during 2004 data taking allow us to anticipate that this value will be improved. At the end of 2005 we expect to start with the so-called second phase of CAST, when the magnet pipes will be filled with a buffer gas so that the axion-photon coherence will be extended. In this way we will be able to search for axions with masses up to 1 eV.

CAST—A CERN Experiment to Search for Solar Axions

The CAST experiment at CERN is the only running solar axion telescope. The first results obtained so far with CAST -PHASE I is presented, which compete with the best astrophysically derived limits of the axion-tophoton coupling. The ongoing PHASE II of the experiment as well as the scheduled upgrades, which improve the axion discovery potential of CAST, are discussed.

Search for Solar Axions with the CCD Detector and X-ray Telescope at CAST Experiment

2015

The CERN Axion Solar Telescope (CAST) is an experiment that uses the world’s highest sensitivity Helioscope to date for solar Axions searches. Axions are weakly interacting pseudoscalar particles proposed to solve the so-called Strong Charge-Parity Problem of the Standard Model. The principle of detection is the inverse Primakoff Effect, which is a mechanism for converting the Axions into easily detectable X-ray photons in a strong transverse magnetic field. The solar Axions are produced due to the Primakoff effect in the hot and dense core of from the coupling of a real and a virtual photon. The solar models predict a peak Axion luminosity at an energy of 3 keV originating mostly from the inner 20% of the solar radius. Thus an intensity peak at an energy of 3 keV is also expected in the case of the X-ray radiation resulting from Axion conversion. CAST uses a high precision movement system for tracking the Sun twice a day with a LHC dipole twin aperture prototype magnet, 9.26 meters...

The CERN Axion Solar Telescope (cast):. Status and Prospects

2003

The CAST experiment is being mounted at CERN. It will make use of a decommissioned LHC test magnet to look for solar axions through its conversion into photons inside the magnetic field. The magnet has a field of 9 Tesla and length of 10 m and is installed in a platform which allows to move it ±8° vertically and ±40° horizontally. According to these numbers we expect a sensitivity in axion-photon coupling gaγγ ≲ 5 × 10-11 GeV-1 for ma ≲ 10-2 eV, and with a gas filled tube gaγγ ≲ 10-10 GeV-1 for ma ≲ 2 eV.

Search for solar axions: The CAST experiment

2006

Hypothetical axion-like particles with a two-photon interaction would be produced in the sun by the Primakoff process. In a laboratory magnetic field they would be transformed into Xrays with energies of a few keV. The CAST experiment at CERN is using a decommissioned LHC magnet as an axion helioscope in order to search for these axion-like particles. The analysis of the 2003 data 1 has shown no signal above the background, thus implying an upper limit to the axion-photon coupling of gaγ < 1.16 × 10 −10 GeV −1 at 95% CL for ma 0.02 eV. The stable operation of the experiment during 2004 data taking allow us to anticipate that this value will be improved. At the end of 2005 we expect to start with the so-called second phase of CAST, when the magnet pipes will be filled with a buffer gas so that the axion-photon coherence will be extended. In this way we will be able to search for axions with masses up to 1 eV.

Search for Solar Axions with the CAST-Experiment

Astroparticle, Particle and Space Physics, Detectors and Medical Physics Applications, 2008

The CAST (CERN Axion Solar Telescope) experiment at CERN searches for solar axions with energies in the keV range. It is possible that axions are produced in the core of the sun by the interaction of thermal photons with virtual photons of strong electromagnetic fields. In this experiment, the solar axions. can be reconverted to photons in the transversal field of a 9 Te sla superconducting magnet. At both ends of the lOm-long dipole magnet three different X-ray detectors were installed , which are sensitive in the interesting photon energy range. Preliminary results from the analysis of the 2004 data are presented: g00 < 0.9 x 10-i o Gev-1 at 953 C.L. for axion masses m0 < 0.02 eV. At the end of 2005, data started to be taken with a buffer gas in the magnet pipes in order to extend the sensitivity to axion masses up to 0.8 eV.

First Results of the CERN Axion Solar Telescope (CAST)

Nuclear Physics B - Proceedings Supplements, 2005

Hypothetical axionlike particles with a two-photon interaction would be produced in the sun by the Primakoff process. In a laboratory magnetic field (''axion helioscope''), they would be transformed into xrays with energies of a few keV. Using a decommissioned Large Hadron Collider test magnet, the CERN Axion Solar Telescope ran for about 6 months during 2003. The first results from the analysis of these data are presented here. No signal above background was observed, implying an upper limit to the axionphoton coupling g a < 1:16 10 ÿ10 GeV ÿ1 at 95% C.L. for m a & 0:02 eV. This limit, assumption-free, is comparable to the limit from stellar energy-loss arguments and considerably more restrictive than any previous experiment over a broad range of axion masses.

First results from the Cern Axion Solar Telescope (CAST)

Identification of Dark Matter, 2005

Hypothetical axionlike particles with a two-photon interaction would be produced in the sun by the Primakoff process. In a laboratory magnetic field (''axion helioscope''), they would be transformed into xrays with energies of a few keV. Using a decommissioned Large Hadron Collider test magnet, the CERN Axion Solar Telescope ran for about 6 months during 2003. The first results from the analysis of these data are presented here. No signal above background was observed, implying an upper limit to the axionphoton coupling g a < 1:16 10 ÿ10 GeV ÿ1 at 95% C.L. for m a & 0:02 eV. This limit, assumption-free, is comparable to the limit from stellar energy-loss arguments and considerably more restrictive than any previous experiment over a broad range of axion masses.

The cern axion solar telescope (CAST): an update

Nuclear Physics B - Proceedings Supplements, 2005

The CERN Axion Solar Telescope (CAST), a 10 meter long LHC, 9 Tesla, test magnet is mounted on a moving platform that tracks the sun about 1.5 hours during sunrise, again during sunset. It moves ±8 0 vertically and ±40 0 horizontally. It has been taking data continuously since July 10, 2003. Data analyzed thus far yield an upper bound on the photon-axion coupling constant, gaγγ ≤ 3 × 10 −10 GeV −1 for axion masses less than 5 × 10 −2 eV.