Tracking and separation of relativistic ions using Timepix3 with a 300 μm thick silicon sensor

AbstraktAbstract

Abstract: The response of a Timepix3 detector (256 × 256 pixels, pixel pitch 55 μm) with a 300 μm thick silicon sensor was studied in relativistic charged particle beams at the Super-Proton-Synchrotron at CERN. The detector was irradiated at different angles in a 400 GeV/c primary proton beam and in a mixed beam created by a 330 GeV/c Pb beam hitting a beryllium target. We present and discuss energy deposition spectra and particle track features for relativistic particles of different stopping power. The proton data shows that a relative energy resolution of approximately 9 % can be achieved. Analysis of deposited energy spectra and tracks in the detector produced by heavier ions are carried out with the aim to investigate the capabilities of the Timepix3 detector for decomposing the mixed beam. Using spectrum stripping technique by iterative Landau curve fitting charge discrimination could be done up to Z = 7 for impact angle of 60 degrees (with respect to the sensor normal). For smaller impact angles the particle charge separation is decreased due to the saturation of the pixel electronics (∼600 keV). Previous works describing the 3D track reconstruction for minimally ionizing particles (Z = 1) were extended in the present work by adding the methodology of heavier ions track reconstruction in 3D.

Abstract: The response of a Timepix3 detector (256 × 256 pixels, pixel pitch 55 μm) with a 300 μm thick silicon sensor was studied in relativistic charged particle beams at the Super-Proton-Synchrotron at CERN. The detector was irradiated at different angles in a 400 GeV/c primary proton beam and in a mixed beam created by a 330 GeV/c Pb beam hitting a beryllium target. We present and discuss energy deposition spectra and particle track features for relativistic particles of different stopping power. The proton data shows that a relative energy resolution of approximately 9 % can be achieved. Analysis of deposited energy spectra and tracks in the detector produced by heavier ions are carried out with the aim to investigate the capabilities of the Timepix3 detector for decomposing the mixed beam. Using spectrum stripping technique by iterative Landau curve fitting charge discrimination could be done up to Z = 7 for impact angle of 60 degrees (with respect to the sensor normal). For smaller impact angles the particle charge separation is decreased due to the saturation of the pixel electronics (∼600 keV). Previous works describing the 3D track reconstruction for minimally ionizing particles (Z = 1) were extended in the present work by adding the methodology of heavier ions track reconstruction in 3D.