To fabricate high performance Bi absorption gratings for use in X-ray differential phase-contrast imaging(DPCI),the micro-casting method was improved via surface modification.Bi_(2)O_(3)was used in place of SiO_(2)as ...To fabricate high performance Bi absorption gratings for use in X-ray differential phase-contrast imaging(DPCI),the micro-casting method was improved via surface modification.Bi_(2)O_(3)was used in place of SiO_(2)as an improved wetting layer.A scanning electron microscopy showed that a high filling-ratio analyzer grating with a period of3μm and a depth of 150μm was obtained.Furthermore,the superiority of the presented analyzer grating to the one fabricated using the traditional micro-casting method was revealed through a comparison of moirépatterns.These tests demonstrate an enhancement to the micro-casting method for the fabrication of absorption gratings.展开更多
Two algorithms for the phase retrieval of hard X-ray in-line phase contrast imaging are presented.One is referred to as Iterative Angular Spectrum Algorithm(IASA)and the other is a hybrid algorithm that combines IASA ...Two algorithms for the phase retrieval of hard X-ray in-line phase contrast imaging are presented.One is referred to as Iterative Angular Spectrum Algorithm(IASA)and the other is a hybrid algorithm that combines IASA with TIE(transport of intensity equation).The calculations of the algorithms are based on free space propagation of the angular spectrum.The new approaches are demonstrated with numerical simulations.Comparisons with other phase retrieval algorithms are also performed.It is shown that the phase retrieval method combining the IASA and TIE is a promising technique for the application of hard X-ray phase contrast imaging.展开更多
基金National Special Foundation of China for Major Science Instrument(61227802)National Natural Science Foundation of China(61405120)
文摘To fabricate high performance Bi absorption gratings for use in X-ray differential phase-contrast imaging(DPCI),the micro-casting method was improved via surface modification.Bi_(2)O_(3)was used in place of SiO_(2)as an improved wetting layer.A scanning electron microscopy showed that a high filling-ratio analyzer grating with a period of3μm and a depth of 150μm was obtained.Furthermore,the superiority of the presented analyzer grating to the one fabricated using the traditional micro-casting method was revealed through a comparison of moirépatterns.These tests demonstrate an enhancement to the micro-casting method for the fabrication of absorption gratings.
基金supported by the National Natural Science Foundation of China(Grant No.60472107)the Natural Science Foundation of Guangdong Province(Grant Nos.04300862 and 04300864)Shenzhen Bureau of Science,Technology&Information(Grant No.200426).
文摘Two algorithms for the phase retrieval of hard X-ray in-line phase contrast imaging are presented.One is referred to as Iterative Angular Spectrum Algorithm(IASA)and the other is a hybrid algorithm that combines IASA with TIE(transport of intensity equation).The calculations of the algorithms are based on free space propagation of the angular spectrum.The new approaches are demonstrated with numerical simulations.Comparisons with other phase retrieval algorithms are also performed.It is shown that the phase retrieval method combining the IASA and TIE is a promising technique for the application of hard X-ray phase contrast imaging.
