Detectors for the Atacama B-mode Search experiment

摘要: Inflation is the leading theory for explaining initial conditions that brought about our homogeneous and isotropic Universe. It predicts presence of gravitational waves in early Universe, which implant a characteristic B-mode polarization pattern on Cosmic Microwave Background (CMB). The Atacama Search (ABS) experiment polarimeter observing from Cerro Toco (located desert Chile at an altitude 5190 m), searching yet undetected signal. ABS carries 480 superconducting Transition Edge Sensor (TES) Bolometers couple 150 GHz radiation via planar Ortho-Mode Transducers (OMTs) mounted output corrugated feedhorns. feedhorn beam projected onto sky through crossed Dragonian reflectors, set reflective absorptive filters, rotating Half Wave Plate (HWP) modulates any polarized signal 10.2 Hz. bolometers are cooled to 300 mK by He3-He4 adsorption fridge system backed pulse tubes. reflectors located within 4 K cavity cryostat, while HWP frictionless air bearings above cryostat window. This thesis discusses development construction detector focal plane, presents results its performance field August 2012. array sensitivity 31 μKs, together with experiment’s unique systematic controls, expected multi-year integration time, could detect tensor scalar ratio r ∼ 0.1.