Larry R. Johnson

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We report initial results of a feasibility study of Proton Computed Tomography and Proton Transmission Radiography for applications in proton therapy treatment planning and patient positioning. The aim of the study is to explore experimentally if PCT, which is based on the measurement of the specific energy loss of protons traversing tissues of different(More)
We report progress on a feasibility study of Proton Computed Tomography and Proton Transmission Radiography for applications in treatment planning and patient positioning for proton radiation therapy. We analyzed data from proton transmission studies through a hollow aluminum cylinder taken with a telescope of silicon detectors with very high spatial and(More)
were grown was revealed to be almost identical to the stoichiometry determined by EPMA of the obtained crystal, the mixing ratio of the anions in the solution was adopted in the chemical formula of the crystal. The results of EPMA of k-(BETS)2FexGa1±xBr1.0Cl3.0 are: for x = 0.50, Fe/Ga/Br/Cl = 0.51:0.49:1.13:2.85 (0.50:0.50:1.00:3.00); for x = 0.40,(More)
Monte Carlo computer programs such as the GEANT4 toolkit include precise models of particle interactions and can be an invaluable tool for studying the feasibility of new imaging techniques such as proton computed tomography (pCT). Presented in this paper is a comparison of laboratory data with GEANT4 predictions for the imaging characteristics of a simple(More)
A new technique for visualizing the steady flow of a new type of test fluid is presented that produces quality photographic results at Reynolds numbers typically found in arterial bypass grafts. Room air functions as the test fluid and smoke from burning incense sticks provides the tracer particles. As an example of this new technique, photographic results(More)
The travel times of compressional waves from quarry explosions of well-known origin times, measured at the University of California network of seismographic stations for the period 1961 to the present, have been examined for evidence of premonitory changes prior to earthquakes of moderate magnitudes in the region. Velocities to seven station sites are(More)
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