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Optimizing Pinhole and Parallel Hole Collimation for Scintimammography with Compact Pixellated Detectors

Description: The relative advantages of pinhole and parallel hole collimators for scintimammography with compact, pixellated gamma detectors were investigated using analytic models of resolution and sensitivity. Collimator design was studied as follows. A desired object resolution was specified for a pixellated detector with a given crystal size and intrinsic spatial resolution and for a given object-to-collimator distance. Using analytic formulas, pinhole and parallel hole collimator parameters were calculated that satisfy this object resolution with optimal geometric sensitivity. Analyses were performed for 15 cm x 20 cm field of view detectors with crystal elements 1.0, 2.0 and 3.0 mm on a side and 140 keV incident photons. The sensitivity for a given object resolution was greater for pinhole collimation at smaller distances, as expected. The object distance at which the pinhole and parallel hole sensitivity curves cross each other is important. The crossover distances increased with larger crystal size for a constant object resolution and increased as the desired object resolution decreases for a constant crystal size. For example, for 4 mm object resolution these distances were 5.5 cm, 6.5 cm and 8 cm for the 1 mm, 2 mm and 3 mm crystal detectors, respectively. The results suggest a strategy of parallel hole collimation for whole breast imaging and pinhole collimation for imaging focal uptake. This could be accomplished with a dual detector system with a different collimator type on each head or a single head system equipped with two collimators and a rapid switching mechanism. Multipinhole collimators have the potential to increase sensitivity yet maintain high image resolution. An experimental SPECT phantom study with a four-pinhole collimator was acquired with a pixellated detector. The iterative maximum-likelihood expectation- maximization (MLEM) reconstruction of a hot sphere in a warm cylinder showed the potential of multipinhole collimation to improve sensitivity for tomographic pinhole ...
Date: November 1, 2002
Creator: Smith, Mark F.; Kieper, Douglas A.; Majewski, Stan; Weisenberger, Andrew G. & Welch, Benjamin
Partner: UNT Libraries Government Documents Department

Experimental And Theoretical High Energy Physics Research At UCLA

Description: This is the final report of the UCLA High Energy Physics DOE Grant No. DE-FG02- 91ER40662. This report covers the last grant project period, namely the three years beginning January 15, 2010, plus extensions through April 30, 2013. The report describes the broad range of our experimental research spanning direct dark matter detection searches using both liquid xenon (XENON) and liquid argon (DARKSIDE); present (ICARUS) and R&D for future (LBNE) neutrino physics; ultra-high-energy neutrino and cosmic ray detection (ANITA); and the highest-energy accelerator-based physics with the CMS experiment and CERN’s Large Hadron Collider. For our theory group, the report describes frontier activities including particle astrophysics and cosmology; neutrino physics; LHC interaction cross section calculations now feasible due to breakthroughs in theoretical techniques; and advances in the formal theory of supergravity.
Date: July 22, 2013
Creator: Cousins, Robert D.
Partner: UNT Libraries Government Documents Department

Data for Elementary-Particle Physics

Description: These data are provided: Masses and .Mean Lives of Elementary Particles; Atomic and Nuclear Properties of Materials; Particle Scattering; Atomic and Nuclear Constants; Particle Decay and Reaction Dynamics; Tentative Data on Strongly lnteracting Particles and Resonances; and Clebsch-Gordan Coefficients and Spherical Harmonics.
Date: April 30, 1963
Creator: Rosenfeld, A. H. & Barkas, W. H.
Partner: UNT Libraries Government Documents Department

Final Report for "Infrared Fixed Points in Multiflavor Lattice Gauge Theory"

Description: The goal of the grant was to apply methods that we have developed with spin and pure gauge models to models with dynamical fermions which are considered as candidates for an alternative to the Higgs mechanism. The work on SU(3) with fundamental quarks and with sextet quarks is described.
Date: September 27, 2013
Creator: Meurice, Yannick & Sinclair, Donald K.
Partner: UNT Libraries Government Documents Department

Final Report for the University-Based Detector Research and Development for the International Linear Collider

Description: The U.S Linear Collider Detector R&D program, supported by the DOE and NSF umbrella grants to the University of Oregon, made significant advances on many critical aspects of the ILC detector program. Progress advanced on vertex detector sensor development, silicon and TPC tracking, calorimetry on candidate technologies, and muon detection, as well as on beamline measurements of luminosity, energy, and polarization.
Date: April 22, 2013
Creator: Brau, James E.
Partner: UNT Libraries Government Documents Department

Research in High Energy Physics

Description: This final report details the work done from January 2010 until April 2013 in the area of experimental and theoretical high energy particle physics and cosmology at the University of California, Davis.
Date: August 9, 2013
Creator: Conway, John S.
Partner: UNT Libraries Government Documents Department

Elementary Particle Physics at Baylor (Final Report)

Description: This report summarizes the activities of the Baylor University Experimental High Energy Physics (HEP) group on the Collider Detector at Fermilab (CDF) experiment from August 15, 2005 to May 31, 2012. Led by the Principal Investigator (Dr. Jay R. Dittmann), the Baylor HEP group has actively pursued a variety of cutting-edge measurements from proton-antiproton collisions at the energy frontier.
Date: August 25, 2012
Creator: Dittmann, J.R.
Partner: UNT Libraries Government Documents Department

Final report on SNAC 11

Description: This report details how the $5,000 DOE grant to support the workshop titled “Sterile Neutrinos at the Crossroads” (or SNAC11) was allocated and spent. The SNAC11 workshop covered three days during which there were 28 talks, multiple discussion sessions, a poster session with 9 posters delivered, and an impromptu public lecture on the OPERA superluminal neutrino result by the former project manager of OPERA (this was the first official OPERA talk on the subject in North America). The workshop scientific agenda can be viewed at http://www.cpe.vt.edu/snac/program.html. Emerging out of the workshop discussions, was the idea to write a comprehensive white paper describing the current state of the light sterile neutrino. This effort soon became an international collaboration. The final document, titled “Light Sterile Neutrinos: A White Paper” has nearly 200 authors, is 267 pages long, and cites 730 unique references. It has been posted the preprint archive as arXiv:1204.5379 [hep-ph]. Workshop local organizing committee co-chairs, Patrick Huber and Jonathan Link, are the white paper’s head editors. The white paper’s sections and section editors are as follows: 1. Theory and Motivation (Gabriela Barenboim, Valencia and Werner Rodejohann, MPI Heidelberg) 2. Astrophysical Evidence (Kev Abazajian, UC Irvine and Yvonne Wong, Aachen) 3. Evidence from Oscillation Experiments (Joachim Kopp, FNAL and Bill Louis, LANL) 4. Global Picture (Thierry Lasserre, CEA Saclay and Thomas Schwetz, MPI Heidelberg) 5. Requirements for Future Measurements (Bonnie Fleming, Yale and Joe Formaggio, MIT) 6. Appendix: Possible Future Experiments (Patrick Huber, Virginia Tech and Jon Link, Virginia Tech) In all 56 people participated in the workshop, of these 11 were young scientists. The workshop was covered in a feature article in Science (Science, 334, (2011), 304-306.). The DOE award was spent, as budgeted, as contractual services to VT CPE, which is the unit within the University which organizes conferences. ...
Date: June 26, 2013
Creator: Huber, Patrick
Partner: UNT Libraries Government Documents Department

High Energy Physics

Description: This grant covered an umbrella program of research in high-­‐energy particle physics at Southern Methodist University during the period 2004-­‐2013. The experimental program evolved during that time. At its early stages it included research on the CLEO experiment at CESR (Coan, Stroynowski, Ye), D0 experiment at Tevatron (Kehoe), preparation for the BTEV experiment at Fermilab (Coan) and construction and commissioning of the Liquid Argon Calorimeter for the ATLAS experiment at LHC (Stroynowski, Ye). In the last three years the program concentrated on the ATLAS experiment at LHC (Kehoe, Sekula, Stroynowski, Ye), D0 experiment at Tevatron (Kehoe) and NOvA experiment at Fermilab (Coan). Professor Sekula had a short-­‐term independent grant for which he is submitting a separate report. The theoretical physics program included work on non-­‐perturbative methods in the light cone representation (McCartor (deceased)), lattice calculations (Hornbostel), and determination of parton distribution functions (Olness). A summary of the accomplishments emphasizing results from the past three years is provided separately for each of the tasks.
Date: June 26, 2013
Creator: Strownowski, Ryszard
Partner: UNT Libraries Government Documents Department