Fizik

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Browsing Fizik by Subject "Axions."

Now showing 1 - 3 of 3
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    In search of the axion particle with RF cavities in cast experiment at CERN
    (Thesis (M.S.) - Bogazici University. Institute for Graduate Studies in Science and Engineering, 2021., 2021.) Özbozduman, Kaan.; Özcan, Veysi Erkcan.; Çetin, Serkant Ali.
    Axion is a pseudo scalar boson that is predicted to solve the strong CP problem and therefore cast light upon curious CP invariance of the strong nuclear interactions. It is also a promising candidate to be the building block of the dark matter. CAST was invented more than 20 years ago as an axion helioscope, searching for high energy solar axions and it has exceeded the expectations throughout its operation. In a published article in 2017, CAST has declared a new research program to explore galactic halo (dark matter) axions. CAST-CAPP detector searches for dark matter axions using four microwave cav ities that operate in 4.7-5.4 GHz band corresponding to ∼19-22 µeV axion mass. It has started operation in 2019, after several years of design, installations and tests. CAST-CAPP is unique in a sense that it utilizes multiple portable rectangular cavities that can be phase-matched in order to amplify the axion signal. In 2 data taking runs, preliminary results indicate that CAST-CAPP has pushed the limits of axion search by exploring new regions in the parameter space.
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    Search for axions with micromegas detectors in the cern cast experiment
    (Thesis (Ph.D.)-Bogazici University. Institute for Graduate Studies in Science and Engineering, 2013., 2013.) Yıldız, Süleyman Cenk.; Arık, Metin.
    The CAST experiment is searching for the axion, which is a light, weakly interacting pseudoscalar particle, that is proposed to solve the so called Strong Charge-Parity Problem. The axions CAST is looking for are produced from photons in the solar core and CAST aims to convert them back into photons in a superconducting LHC dipole magnet and detect the photons in the x-ray detectors attached to ends of each magnet bore. CAST uses three micromegas and a CCD detector and can track the Sun during sunset and sunrise. The two of the micromegas take tracking data during the sunset solar tracking, and were used for the rst time in 2008. The analysis of the data taken in 2008 with these two detectors show no signal of axions, and new upper limits on the axion mass-coupling constant parameter space are established due to sensitivity of detectors for the axion mass range of 0:38eV to 0:65eV.
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    Solar axion production and detection mechanisms
    (Thesis (M.S.)-Bogazici University. Institute for Graduate Studies in Science and Engineering, 2009., 2009.) Özuğurel, Umut Deniz.; Arık, Metin.
    Production mechanisms of the axion particle in the Sun as well as the detection principle and the data analysis methods that the CAST experiment is based on are reviewed. It is shown that the solar axion production can be explained both by the Primako e ect with a reduced decay width due to plasma screening e ects and by the electromagnetic plasma excitations up to a momentum limit. The analysis of CAST data which results in an upper limit on the axion-photon coupling constant for a range of axion mass is explained in connection with the solar axion ux and the detection principle. Additionally, technical details about CAST is given. Finally, a survey on data collected during the rst part of the second phase of CAST is presented.