Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2012 · 19 citations · 0 references
EngineeringAerospace EngineeringElectrical EngineeringInstrumentationOpticsRadiation MeasurementDetector TechnologyPolarization OpticsX-ray DetectionX-ray DetectorsX-ray OpticsX-ray PolarimetryDetector Quantum EfficiencyPhotoelectric EffectPolarimeter DesignPolarizationPolarization MeasurementsQuantum EfficiencyTime Projection ChambersX-ray Polarization Measurements
The Gravity and Extreme Magnetism Small Explorer (GEMS) will realize its scientific objectives through high sensitivity linear X-ray polarization measurements in the 2-10 keV band. The GEMS X-ray polarimeters, based on the photoelectric effect, provide a strong polarization response with high quantum efficiency over a broad band-pass by a novel implementation of the time projection chamber (TPC). This paper will discuss the basic principles of the TPC polarimeter and describe the details of the mechanical and electrical design of the GEMS flight polarimeter. We will present performance measurements from two GEMS engineering test units in response to polarized and unpolarized X-rays and before and after thermal and vibration tests performed to demonstrate that the design is at a technology readiness level 6 (TRL-6).