High Resolution, Low Cost Small Animal PET Imager

65691 Extremely bright, affordable, photocathode electron sources are required for future DOE facilities such as the Next Linear Collider and Next Generation Light Sources. An electron gun with greater than 1 nC per bunch and less than 1 p mm-mrad normalized transverse rms emittance would meet this need, but the sub 1 p mm-mrad target remains elusive. Because axisymmetry has been shown to be important for minimizing emittance growth, this project will develop an axisymmetric electron gun that optimizes the standard emittance-compensation technique to break the 1 p emittance barrier. Phase I developed a suitable radio frequency (RF) design that provides all necessary features of this novel gun concept. Beam dynamics calculations showed that the subject electron gun would provide enhanced performance over existing designs. Phase II will complete the RF design of the axisymmetric, emittance-compensated gun and design and fabricate a prototype device. The prototype gun will then be tested at high RF powers and the quality of the generated electron beam will be measured. Commercial Applications and Other Benefits as described by the awardee: The electron gun should serve as the injector for advanced, high-brightness X-ray sources for both medical and protein crystallography applications. In the medical market the ability of a monochromatic, tunable, x-ray source to deliver much clearer diagnostic images with a much smaller dose fraction would be extremely attractive for such applications as breast cancer screening. In the pharmaceutical and biomedical industries, a compact high-performance protein crystallography unit would find application in the production of ¿designer drugs¿ and in the ongoing task of mapping and DNA sequencing the human genome