21 PINHOLE, NONROTATIONAL CARDIAC SPECT SYSTEM

Not Available Acoustic bandgaps are frequency domains where the propagation of sound and phonons is forbidden. In the last few years, significant advances have been made, mostly in Europe in the area of theoretical characterization of these materials and devices. Experimental configurations have focused on materials with specific 2-D and 3-D internal geometries which exhibit bandgap properties. It is possible, therefore, to make a device with an intricate internal geometry using free form fabrication techniques. The proposed effort is aimed at developing theoretical models for the design and performance prediction of the acoustic bandgap (ABG) materials and devices, leading to the fabrication and testing of a prototype that exhibits acoustic bandgap properties. During Phase I, an analytical design tool for the design and performance prediction of an ABG device will be developed, modifying codes that have been successfully employed in past research. By the end of Phase I, a prototype will also have been fabricated andcharacterized. During Phase II, specific vibration isolation applications will be targeted for insertion of the ABG device technology. In addition, the design tool will be refined.