Conversion mode photon analysis using the alpha magnetic spectrometer (AMS-02)

Postacı, Emirhan
The Alpha Magnetic Spectrometer (AMS-02) is a particle physics detector operating as an external module on the International Space Station (ISS). It is designed to search for antimatter and dark matter by measuring cosmic ray composition and flux. Dark matter does not interact electromagnetically, so cannot be detected directly with optical instruments. A strong candidate of dark matter is the lightest supersymmetric particle which can annihilate into the Standard Model particles, called the neutralino. If neutralinos annihilate in the galactic halo, they could result in an excess of particles that can be detected by the AMS-02. Any peaks in the positron, antiproton, or photon spectrum could signal the presence of neutralinos, but would need to be distinguished from other complex astrophysical signals. Photon analysis can be done in two ways: calorimetric mode and conversion mode. In the calorimetric mode of photon analysis, photons leave no trace in subdetectors down to the ECAL. In the conversion mode, photons which are converted to electron-positron pairs in the upper parts of the AMS-02 are studied. This thesis outlines the study of conversion mode photon analysis above 100 GeV energy.


Calorimetric mode photon analysis using the alpha magnetic spectrometer (AMS-02)
Türkoğlu, Cenk; Demirköz, Melahat Bilge; Department of Physics (2015)
Alpha Magnetic Spectrometer (AMS-02) is a particle detector built for the purpose of detecting primordial anti-matter and signals of dark matter. AMS-02 operates as an external module on the International Space Station and will be operational for at least 10 years. For finding traces of the strongest dark matter candidate, neutralino, peaks in the background positron, antiproton and gamma ray flux have to be studied. For this purpose, AMS-02 includes a permanent magnet that bends particles and anti-particle...
Properties of Cosmic Helium Isotopes Measured by the Alpha Magnetic Spectrometer
Aguilar, M.; et. al. (American Physical Society (APS), 2019-11-01)
Precision measurements by the Alpha Magnetic Spectrometer (AMS) on the International Space Station of He-3 and He-4 fluxes are presented. The measurements are based on 100 million He-4 nuclei in the rigidity range from 2.1 to 21 GV and 18 million He-3 from 1.9 to 15 GV collected from May 2011 to November 2017. We observed that the He-3 and He-4 fluxes exhibit nearly identical variations with time. The relative magnitude of the variations decreases with increasing rigidity. The rigidity dependence of the He-...
Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV
Aad, G.; et. al. (Springer Science and Business Media LLC, 2013-03-01)
The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of root s = 7 TeV corresponding to an integrated luminosity of 38 pb(-1). Jets are reconstructed with the anti-k(t) algorithm with distance parameters R = 0.4 or R = 0.6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT >= 20 GeV and pseudorapidities vertical ...
Room temperature sub-micron magnetic imaging by scanning Hall probe microscopy
SANDHU, ADARSH; MASUDA, HİROSHİ; Oral, Ahmet; BENDİNG, SİMON J (IOP Publishing, 2001-06-01)
An ultra-high sensitive room temperature scanning Hall probe microscope (RT-SHPM) system incorporating a GaAs/AlGaAs micro-Hall probe was used for the direct magnetic imaging of localized magnetic field fluctuations in very close proximity to the surface of ferromagnetic materials. The active area, Hall coefficient and field sensitivity of the Hall probe were 0.8 mum x 0.8 mum, 0.3 Omega /G and 0.04G/root Hz, respectively. The use of a semiconducting Hall probe sensor enabled measurements in the presence of...
BILIKMEN, S; OMAR, A (Springer Science and Business Media LLC, 1994-05-01)
The Hamiltonian for an electron travelling through a large-amplitude backward electromagnetic wave, an axial guide magnetic field and radiation field is formulated. Poincare surface-of-section plots show that this Hamiltonian is non-integrable, and leads to chaotic trajectories. Equilibrium conditions are derived in the limit where the radiation field approaches zero. Compared to conventional FEL, the total energy of the system at pondermotive resonance E(c) is large, while the electron's critical energy...
Citation Formats
E. Postacı, “Conversion mode photon analysis using the alpha magnetic spectrometer (AMS-02),” M.S. - Master of Science, Middle East Technical University, 2014.