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

CAST: A search for solar axions at CERN

Arxiv preprint hep-ex/0304024, 2003

The new axion helioscope at CERN started acquiring data during September of 2002: CAST (Cern Axion Solar Telescope) employs a decommissioned LHC dipole magnet to convert putative solar axions or axion-like particles into detectable photons. The unprecedented dipole magnet intensity and length (9.5 T, 10 m) results in a projected sensitivity that surpasses astrophysical constraints on these particles for the first time, increasing the chance of discovery. The use of X-ray focusing optics and state-of-the-art detector technology has led to an extremely low background for an experiment above ground. A brief status report is given, with emphasis on the tracking and control system and possible future extensions.

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.

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.

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.

Latest results and prospects of the CERN Axion Solar Telescope

Journal of Physics: Conference Series, 2011

The CERN Axion Solar Telescope (CAST) experiment searches for axions from the Sun converted into few keV photons via the inverse Primakoff effect in the high magnetic field of a superconducting Large Hadron Collider (LHC) decommissioned test magnet. After results obtained with vacuum in the magnet pipes (phase I of the experiment) as well as with 4 He the collaboration is now immersed in the data taking with 3 He, to be finished in 2011. The status of the experiment will be presented, including a preliminary exclusion plot of the first 3 He data. CAST is currently sensitive to realistic QCD axion models at the sub-eV scale, and with axion-photon couplings down to the ∼ 2 × 10 −10 GeV −1 , compatible with solar life limits. Future plans include revisiting vaccuum and 4 He configurations with improved sensitivity, as well as possible additional search for non-standard signals from chamaleons, paraphotons or other WISPs. For the longer term, we study the feasibility of an altogether improved version of the axion helioscope concept, with a jump in sensitivity of about one order of magnitude in gaγ beyond CAST.

First Results from the CERN Axion Solar Telescope

Physical Review Letters, 2005

Hypothetical axion-like 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 X-rays with energies of a few keV. Using a decommissioned LHC test magnet, CAST 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 axion-photon coupling gaγ < 1.16 × 10 −10 GeV −1 at 95% CL for ma < ∼ 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 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.