Search for solar axions: The CAST experiment (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.

In search of axions: The CAST experiment

2006

The CERN Axion Solar Telescope (CAST) experiment uses a decommissioned LHC test magnet in conjunction with three different technology X-ray photon detectors and tracks the sun to look for the elusive axion. Axions or axion-like particles with a two-photon interaction can be produced in the Sun by the Primakoff process, according to the theory. In a laboratory magnetic field they can be transformed into X-rays with energies of a few keV. CAST has been running for about 6 months during 2003 and most of 2004. The first results from the analysis of the 2003 data are presented here. No signal above background was observed, implying an upper limit to the axion to photon coupling g αγγ < 1.16 × 10-10 GeV-1 at 95% CL for m α ≤ 0.02 eV. This limit is comparable to the limit from stellar energy loss arguments and considerably more restrictive than any previous experiment in this axion mass range.

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.

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.

Recent Constraints on Axion-photon and Axion-electron Coupling with the CAST Experiment

Physics Procedia, 2015

The CERN Axion Solar Telescope (CAST) is a helioscope looking for axions arising from the solar core plasma and arriving to Earth. The experiment, located in Geneva (Switzerland) is able to follow the Sun during sunrise and sunset. Four x-ray detectors mounted on both ends of the magnet wait for photons from axion-to-photon conversion due to the Primakoff effect. Up to date, with the completion of Phases I and II, CAST has been looking for axions that could be produced in the Sun by both, hadronic and non-hadronic mechanisms.

Solar axion search with the CAST experiment

2008

The CAST (CERN Axion Solar Telescope) experiment is searching for solar axions by their conversion into photons inside the magnet pipe of an LHC dipole. The analysis of the data recorded during the first phase of the experiment with vacuum in the magnet pipes has resulted in the most restrictive experimental limit on the coupling constant of axions to photons. In the second phase, CAST is operating with a buffer gas inside the magnet pipes in order to extent the sensitivity of the experiment to higher axion masses. We will present the first results on the 4 He data taking as well as the system upgrades that have been operated in the last year in order to adapt the experiment for the 3 He data taking. Expected sensitivities on the coupling constant of axions to photons will be given for the recent 3 He run just started in March 2008.

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.

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...