In this Phase II project, we propose to develop, construct, and deliver to NASA a prototype single-sided computed tomography time-domain terahertz (single-sided CT TD-THz) scanner accessory. This accessory will be suitable to be mounted onto a non-destructive evaluation (NDE) imaging gantry for the single-sided inspection of spacecraft and launch vehicle composite structures. The single-sided CT TD-THz scanner will be an accessory which works with existing T-Ray 4000REG TD-THz NDE imaging instruments owned by NASA (and other aerospace firms). We will also develop, and deliver a software package which employs the model-based image reconstruction (MBIR) methods. The MBIR method allows the reconstruction of 2D slices in depth from the data acquired by the single-sided CT TD-THz scanner. These 2D slices can then be stacked laterally to generate 3D images of sub-surface structures, features and defects. Time-domain terahertz imaging in the 0.1 to 3 THz spectral range is currently being used to characterize defects in Space Shuttle insulation and related materials. The proposed project will largely be configured from standard Picometrix THz sub-components, but incorporate measurements of the scattered THz fields, enabling full 3D reflection-mode reconstruction of non-metallic materials where only one side is accessible.
Potential NASA Commercial Applications: (Limit 1500 characters, approximately 150 words) The capabilities provided by a single-sided CT TD-THz NDE imager will be valuable in characterizing new spacecraft materials in complex 3-dimensional forms. Material examples include SOFI and other foam materials, TUFI and other thermal protection systems (TPS), Phenolic Impregnated Carbon Ablator (PICA) and adhesive systems, and other non-conductive polymer composite structures. Example NDE applications where these materials are used include inspection of soft shell fan containment, thermal protection systems, composite overwrap pressure vessels (COPV), and inflatable orbital habitats. The technique is fully applicable to single-sided imaging and can locate and quantify internal structure, regions of damage, porosity, cracking, delaminations, intrusion, and other sub-surface properties.
Potential NON-NASA Commercial Applications:
: (Limit 1500 characters, approximately 150 words) The commercial potential of the technology from a successful Phase II development effort extends well beyond the NASA Polymer matrix composites are used in automobile and ships and many other consumer and industrial products. Single-sided CT TD-THz 3D imaging applications can include inspection of automobile dashboards, imaging inspection for delamination of printed circuit boards, inspection of pipe insulation, as well as with manufactured parts such as pure plastic and paper products. Single-sided CT TD-THz imaging benefits homeland security applications under development such as personnel and luggage inspection for concealed weapons and explosives (in luggage, shoes, etc.). single-sided CT TD-THz imaging and spectroscopy can inspect items in shipment such as mail, cardboards packages, and plastic and wood crates.
Technology Taxonomy Mapping: (NASA's technology taxonomy has been developed by the SBIR-STTR program to disseminate awareness of proposed and awarded R/R&D in the agency. It is a listing of over 100 technologies, sorted into broad categories, of interest to NASA.) Aircraft Engines Ceramics Composites Inflatable Launch and Flight Vehicle Microwave/Submillimeter Optical Optical & Photonic Materials Photonics Propellant Storage Structural Modeling and Tools Tankage Thermal Insulating Materials Tools
