The highest resolution of images of soft matter and biological materials is ultimately limited by modification of the structure,induced by the necessarily high energy of short-wavelength radiation.Imaging the inelasti...The highest resolution of images of soft matter and biological materials is ultimately limited by modification of the structure,induced by the necessarily high energy of short-wavelength radiation.Imaging the inelastically scattered X-rays at a photon energy of 60 keV(0.02 nm wavelength)offers greater signal per energy transferred to the sample than coherent-scattering techniques such as phase-contrast microscopy and projection holography.We present images of dried,unstained,and unfixed biological objects obtained by scanning Compton X-ray microscopy,at a resolution of about 70 nm.This microscope was realised using novel wedged multilayer Laue lenses that were fabricated to sub-ångström precision,a new wavefront measurement scheme for hard X rays,and efficient pixel-array detectors.The doses required to form these images were as little as 0.02%of the tolerable dose and 0.05%of that needed for phase-contrast imaging at similar resolution using 17 keV photon energy.The images obtained provide a quantitative map of the projected mass density in the sample,as confirmed by imaging a silicon wedge.Based on these results,we find that it should be possible to obtain radiation damage-free images of biological samples at a resolution below 10 nm.展开更多
After the end of data taking in 2007,the experiments H1 and ZEUS have entered into an intense phase of data analysis.Recent results of this effort on neutral （NC） and charged current （CC） cross sections at high Q ...After the end of data taking in 2007,the experiments H1 and ZEUS have entered into an intense phase of data analysis.Recent results of this effort on neutral （NC） and charged current （CC） cross sections at high Q 2,the longitudinal structure function F L,inclusive diffraction,heavy flavour production and on searches for glueballs are presented.Also shown are results of a combined analysis on inclusive NC and CC cross sections performed by H1 and ZEUS using HERA-I data.展开更多
基金We thank Martin Domaracky,Florian Laucks,Jerome Carnis(CFEL)for support with controls and data acquisition software,Sabrina Bolmer,Harumi Nakatsutsumi,Tjark Delmas(CFEL)for technical work,Christian Hamm(AWI,Bremerhaven,Germany)for the diatom sample,Klara Gregorič(Univ.of Ljubljana,Slovenia)and Iosifina Sarrou for preparing the spirulina sample,and Miriam Barthelmeß(CFEL)for the silicon sample.We also thank X-Spectrum(Hamburg,Germany)for support with CdTe detectors.We acknowledge support by DESY(Hamburg,Germany),a member of the Helmholtz Association HGF and by the Cluster of Excellence‘Advanced Imaging of Matter’of the Deutsche Forschungsgemeinschaft(DFG)-EXC 2056-project ID 390715994.
文摘The highest resolution of images of soft matter and biological materials is ultimately limited by modification of the structure,induced by the necessarily high energy of short-wavelength radiation.Imaging the inelastically scattered X-rays at a photon energy of 60 keV(0.02 nm wavelength)offers greater signal per energy transferred to the sample than coherent-scattering techniques such as phase-contrast microscopy and projection holography.We present images of dried,unstained,and unfixed biological objects obtained by scanning Compton X-ray microscopy,at a resolution of about 70 nm.This microscope was realised using novel wedged multilayer Laue lenses that were fabricated to sub-ångström precision,a new wavefront measurement scheme for hard X rays,and efficient pixel-array detectors.The doses required to form these images were as little as 0.02%of the tolerable dose and 0.05%of that needed for phase-contrast imaging at similar resolution using 17 keV photon energy.The images obtained provide a quantitative map of the projected mass density in the sample,as confirmed by imaging a silicon wedge.Based on these results,we find that it should be possible to obtain radiation damage-free images of biological samples at a resolution below 10 nm.
文摘After the end of data taking in 2007,the experiments H1 and ZEUS have entered into an intense phase of data analysis.Recent results of this effort on neutral （NC） and charged current （CC） cross sections at high Q 2,the longitudinal structure function F L,inclusive diffraction,heavy flavour production and on searches for glueballs are presented.Also shown are results of a combined analysis on inclusive NC and CC cross sections performed by H1 and ZEUS using HERA-I data.
