This project will develop a technique that will enable the construction of very-high-precision collimators with diameters of at least 10 cm. The collimators will be capable of modulating 90 percent or more of gamma rays to 200 MeV and neutrons to 500 MeV. The collimators will be constructed from thin foils of high density metal (presumably tungsten). The foils will be assembled to form collimators with slit dimensions equal to the foil thicknesses. The foil thickness can be 20 microns or wider. The foils will be held together by low-Z spacers, which will obscure in the visible less than 50 percent of the slits' field-of-view for 20-micron foils and less than 25 percent of the field-of-view for 100-micron foils. The standard deviation of misplacing the foils in the collimator assembly, which is defined as the difference between the measured and the ideal locations, will be less than 10 percent of the collimators pitch (foil plus slit widths) for the 20-micron-foil assemblies and on the order of 5 percent for the 100-micron-foil assemblies.
Potential Commercial Applications:High-precision collimators may be used in laboratory x-ray and gamma-ray imaging of radiation emitted by accelerators or in future, modulating, Fourier transform microscopes which may be employed in medical and metallurgical applications. Future NASA missions may use collimators for imaging high-energy radiation from astrophysical objects. In particular, the collimator can be used on the high- energy solar physics (HESP) satellite.
