A new image reconstruction method was developed for a Compton camera. A simulation to determine a γ-ray source position was performed by using the simulation tool, GEANT4. An image reconstruction was made in two step...A new image reconstruction method was developed for a Compton camera. A simulation to determine a γ-ray source position was performed by using the simulation tool, GEANT4. An image reconstruction was made in two steps. First, a three dimensional image was constructed and projected in one selected plane, then the points from each ellipse was picked up by taking the peak points of a density distribution of crossing points between the ellipse and the first step image. The second step procedure improved the accuracy and the spatial resolution of a position de- termination significantly, comparing with the image obtained by only the first step. The accuracy and the resolution for a point source were obtained to be about 0.02 mm and (1.35±0.15) mm, respectively. The same procedure was applied to an imaging of the distributed γ-ray source.展开更多
Proton resonant states in 22Mg have been investigated by the resonant elastic scattering of 21Na+p. The 21Na beam with a mean energy of 4.00 MeV/u was separated by the CNS radioactive ion beam separator(CRIB) and bomb...Proton resonant states in 22Mg have been investigated by the resonant elastic scattering of 21Na+p. The 21Na beam with a mean energy of 4.00 MeV/u was separated by the CNS radioactive ion beam separator(CRIB) and bombarded a thick(CH2)n target. The energy spectra of recoiled protons were measured at scattering angles of θcm ≈172° and 146°,respectively. A new state at 7.06 MeV has been observed clearly and another new one at 7.28 MeV is tentatively identified due to its low statistics. The proton resonant parameters were deduced from an R-matrix analysis of the differential cross section data. The astrophysical resonant reaction rate for the 18Ne(α,p)21Na reaction has been estimated,and it is about five times larger than that assumed before.展开更多
文摘A new image reconstruction method was developed for a Compton camera. A simulation to determine a γ-ray source position was performed by using the simulation tool, GEANT4. An image reconstruction was made in two steps. First, a three dimensional image was constructed and projected in one selected plane, then the points from each ellipse was picked up by taking the peak points of a density distribution of crossing points between the ellipse and the first step image. The second step procedure improved the accuracy and the spatial resolution of a position de- termination significantly, comparing with the image obtained by only the first step. The accuracy and the resolution for a point source were obtained to be about 0.02 mm and (1.35±0.15) mm, respectively. The same procedure was applied to an imaging of the distributed γ-ray source.
基金Japanese Ministry of Education, Culture,Sports,and Technology,Japan(13440071,14740156)Grants-in-Aids for JSPS,Japan(1604055)
文摘Proton resonant states in 22Mg have been investigated by the resonant elastic scattering of 21Na+p. The 21Na beam with a mean energy of 4.00 MeV/u was separated by the CNS radioactive ion beam separator(CRIB) and bombarded a thick(CH2)n target. The energy spectra of recoiled protons were measured at scattering angles of θcm ≈172° and 146°,respectively. A new state at 7.06 MeV has been observed clearly and another new one at 7.28 MeV is tentatively identified due to its low statistics. The proton resonant parameters were deduced from an R-matrix analysis of the differential cross section data. The astrophysical resonant reaction rate for the 18Ne(α,p)21Na reaction has been estimated,and it is about five times larger than that assumed before.
