The positron-electron annihilation process in(2,2)-difluoropropane molecule and the corresponding gammaray spectra are studied by quantum chemistry method.The positrophilic electrons in(2,2)-difluoropropane molecule a...The positron-electron annihilation process in(2,2)-difluoropropane molecule and the corresponding gammaray spectra are studied by quantum chemistry method.The positrophilic electrons in(2,2)-difluoropropane molecule are found for the first time.The theoretical predictions show that the outermost 2s electrons of fluoride atoms play an important role in positron-electron annihilation process of(2,2)-difluoropropane.In the present scheme,the correlation coefficient between the theoretical gamma-ray spectra and the experiments can be 99%.The present study gives an alternative annihilation model for positron-electron pair in larger molecules.展开更多
The Positron Emission Tomography (PET) applying the coincidence detection of the two 7-photons emitted by the annihilation of positron-electron pair can be used to image tumor with a high spatial resolution (<4 mm)...The Positron Emission Tomography (PET) applying the coincidence detection of the two 7-photons emitted by the annihilation of positron-electron pair can be used to image tumor with a high spatial resolution (<4 mm)[1]. But the cost of PET is proportional to its dimension. A compact PET detector camera was developed. Fig.1 shows the schematic diagram of the experimental measurement setup. Two detectors consist展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.11347011the Natural Science Foundation Project of Shandong Province under Grant No.ZR2011AM0102014 Technology Innovation Fund of Ludong University under Grant Nos.1d151007 and ld15l016
文摘The positron-electron annihilation process in(2,2)-difluoropropane molecule and the corresponding gammaray spectra are studied by quantum chemistry method.The positrophilic electrons in(2,2)-difluoropropane molecule are found for the first time.The theoretical predictions show that the outermost 2s electrons of fluoride atoms play an important role in positron-electron annihilation process of(2,2)-difluoropropane.In the present scheme,the correlation coefficient between the theoretical gamma-ray spectra and the experiments can be 99%.The present study gives an alternative annihilation model for positron-electron pair in larger molecules.
文摘The Positron Emission Tomography (PET) applying the coincidence detection of the two 7-photons emitted by the annihilation of positron-electron pair can be used to image tumor with a high spatial resolution (<4 mm)[1]. But the cost of PET is proportional to its dimension. A compact PET detector camera was developed. Fig.1 shows the schematic diagram of the experimental measurement setup. Two detectors consist
