Abstract
Sunset solar axions traversing the intense magnetic field of the CERN Axion Solar Telescope (CAST) experiment may be detected in a time projection chamber (TPC) detector, as point-like x-rays signals. These signals could be masked, however, by the inhomogeneous background of materials in the experimental site. A detailed analysis, based on the detector characteristics, the background radiation at the CAST site, simulations and experimental results, has allowed us to design a shielding which reduces the background level by a factor of ∼4 compared to the detector without shielding, depending on its position, in the energy range between 1 and 10 keV. Moreover, this shielding has improved the homogeneity of background measured by the TPC.
Highlights
T he C A ST experim ent [1]isplaced atC ER N and m akes use ofa decom m issioned LH C testm agnetto look forsolaraxionsthrough itsPrim ako conversion into photonsinside the m agnetic eld
A tthe end ofthe pipes,three detectorslook forthe X -raysoriginated by the conversion ofthe axionsinside them agnetw hen itpointsto the Sun.T he two apertures ofoneoftheendsofthem agnetarecovered by a conventionalT im eProjection C ham ber (T PC ) [2]facing \sunset" axions w hile in the opposite end,a C harge C oupled D evice (C C D ) [3]coupled to an X -ray focusing telescope [4], and a M icrom egas detector [5] search for \sunrise" axions
T he C A ST experim ent is located at one ofthe buildings ofthe SR 8 experim entalarea at C ER N .T he lower part ofthe walls around is m ade ofconcrete
Summary
T he C A ST experim ent [1]isplaced atC ER N and m akes use ofa decom m issioned LH C testm agnetto look forsolaraxionsthrough itsPrim ako conversion into photonsinside the m agnetic eld. T he rst results from the 2003 data analysis im plied an upperlim itto the axion-photon coupling ga < 1:16 10 10 G eV 1 [6]. A ll three detectors use discrim ination techniques to reduce background contam ination ofthe expected signal. Sim ple requirem ents,depending on each detector,elim inate m ost of the background due to charged particles like cosm ic rays, alpha and beta radiation [2,3,4,5]. T heir interactions w ith m aterialnear the detectors can generate low energy photons via the C om pton e ect and X -rays (as those from copper identi ed in experim ental spectra [3]). A few rem arks sum m arizing the study
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
