Solar axion experiments using coherent primakoff conversion in single crystals (original) (raw)
Related papers
Physics Letters B, 1998
It is assumed that axions exist and are created in the sun by Primakoff conversion of photons in the Coulomb fields of nuclei. Detection rates are calculated in germanium detectors due to the coherent conversion of axions to photons in the lattice when the incident angle fulfills the Bragg condition for a given crystalline plane. The rates are correlated with the relative positions of the sun and detector yielding a characteristic recognizable sub-diurnal temporal pattern. A major experiment is proposed based on a large detector array.
Prospects for solar axion searches with crystals via Bragg scattering
Nuclear Physics B - Proceedings Supplements, 2000
A calculation of the expected signal due to Primakov coherent conversion of solar axions into photons via Bragg scattering in several solid-state detectors is presented and compared with present and future experimental sensitivities. The axion window ma > ∼ 0.03 eV (not accessible at present by other techniques) could be explored in the foreseeable future with crystal detectors to constrain the axion-photon coupling constant gaγγ below the latest bounds coming from helioseismology. On the contrary a positive signal in the sensitivity region of such devices would imply revisiting other more stringent astrophysical limits derived for the same range of the axion mass. The application of this technique to the COSME germanium detector which is taking data at the Canfranc Underground Laboratory leads to a 95% C.L. limit gaγγ ≤ 2.8 × 10 −9 GeV −1 .
Theoretical Expectations and Experimental Prospects for Solar Axions Searches with Crystal Detectors
1999
A calculation of the expected signal due to Primakov coherent conversion of solar axions into photons via Bragg scattering in several solid--state detectors is presented and compared with present and future experimental sensitivities. The axion window m_a>~0.03 eV (not accessible at present by other techniques) could be explored in the foreseeable future with crystal detectors to constrain the axion--photon coupling constant below the latest bounds coming from helioseismology. On the contrary a positive signal in the sensitivity region of such devices would imply revisiting other more stringent astrophysical limits derived for the same range of the axion mass.
Prospects of solar axion searches with crystal detectors
Astroparticle Physics, 1999
A calculation of the expected signal due to Primakoff coherent conversion of solar axions into photons via Bragg scattering in several crystal detectors is presented. The results are confronted with the experimental sensitivities of present and future experiments concluding that the sensitivity of crystal detectors does not challenge the globular cluster limit on the axion-photon coupling g aγγ . In particular, in the axion mass window m a > ∼ 0.03 eV explored with this technique (not accessible at present by other methods) g aγγ might be constrained down to 10 −9 GeV −1 (the recent helioseismological bound) provided that significant improvements in the parameters and performances of these detectors be achieved and large statistics accumulated. This bound should be considered as a minimal goal for the sensitivity of future crystal experiments. Consequently, finding a positive signal at this level of sensitivity would necessarily imply revisiting other more stringent astrophysical limits derived for the same range of m a values.
Experimental search for solar axions
Nuclear Physics B - Proceedings Supplements, 1999
A new technique has been used to search for solar axions using a single crystal germanium detector. It exploits the coherent conversion of axions into photons when their angle of incidence satisfies a Bragg condition with a crystalline plane. The analysis of approximately 1.94 kg.yr of data from the 1 kg DEMOS detector in Sierra Grande, Argentina, yields a new laboratory bound on axion-photon coupling of gaγγ < 2.7 × 10 −9 GeV −1 , independent of axion mass up to ∼ 1 keV. * Supported partially by grants from CONICET, Fundación ANTORCHAS and UNSAM
Search for solar axions by Primakoff effect in NaI crystals
Physics Letters B, 2001
The results of a search for possible signal due to Primakoff coherent conversion of solar axions into photons in NaI(Tl) are presented. The experiment has been carried out at the Gran Sasso National Laboratory of INFN; the used statistics is 53 437 kg day. The presently most stringent experimental limit on g aγ γ from this process is obtained: g aγ γ < 1.7 × 10 −9 GeV −1 (90% C.L.). In particular, the axion mass window m a 0.03 eV, not accessible by other direct methods, is explored and KSVZ axions with mass larger than 4.6 eV are excluded at 90% C.L.
Laboratory limits on solar axions from an ultralow-background germanium spectrometer
Physical review D: Particles and fields, 1987
Laboratory bounds on the couplings to electrons of light pseudoscalars such as axions, familons, majorons, etc. are set with an ultralow background germanium spectrometer using a realistic model for the sun. In particular Dine-Fischler-Srednicki axion models with F/2zi 2 0.5 x lo7 GeV are excluded. It should be emphasized that this is a laboratory bound. It does not rely on a detailed understanding of the dynamics and evolution of red giants, white dwarfs or other stars as do the more speculative astrophysical bounds which are competitive with our laboratory bound. The lower limit should be improved to F/2zd > 1.8 x lo7 GeV in the near future. It is shown that semiconducting Ge detectors for axions could eventually set limits F/2zd > lo8 GeV. If discovered, axions or other light weakly interacting bosons would not only allow us to study physics at energies beyond the reach of accelerators but would also provide a new laboratory tool to study the deep interior of stars.
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: 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.