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In order to expand applications of the Lanzhou microbeam the resent improvements were introduced in its slits, lens system and target chamber. In this study a beam optics of the new system was calculated for the 12C+6 ion beam of 966 MeV. To compensate a negative influence of a sector magnet dispersion on the beam dynamics an excitation of the magnetic quadrupole between two bending dipoles was determined. By varying parameters of the final triplet of magnetic quadrupole lenses a set of the microbeam systems with a stigmatic focusing were obtained. The best two of them were selected applying an optimization for a beam collimation by object and divergence slits. Simulation of the beam dynamics after the collimation allowed to determine the slit sizes that provide the highest current in the 1 µm probe on the target for these microbeam systems. Additionally, to improve the beam parameters at the microbeam entrance and then match the system parameters with this beam, the approach of an automatic probe-forming system is proposed. It is aimed at providing the highest possible resolution of the microbeam for the different beam varieties from a cyclotron. [ABSTRACT FROM AUTHOR]

To investigate the spatiotemporal dynamics of DNA damage and repair after the ion irradiation, an online live cell imaging system has been established based on the microbeam facility at Institute of Modern Physics (IMP). The system could provide a sterile and physiological environment by making use of heating plate and live cell imaging solution. The phototoxicity was investigated through the evaluation of DNA repair protein XRCC1 foci formed in HT1080-RFP cells during the imaging exposure. The intensity of the foci induced by phototoxicity was much lower compared with that of the foci induced by heavy ion hits. The results showed that although spontaneous foci were formed due to RFP exposure during live cell imaging, they had little impact on the analysis of the recruitment kinetics of XRCC1 in the foci induced by the ion irradiation. [ABSTRACT FROM AUTHOR]

The polyethylene terephthalate (PET) films were irradiated with single 6.9 MeV/u 58 Ni 19+ ions at the Lanzhou Interdisciplinary Heavy Ion Microbeam (LIHIM), and single conical nanopores were produced by asymmetric chemical etching of the latent ion tracks. Then, the current-voltage (I–V) characteristic was measured in LiCl, NaCl, KCl, MgCl 2 , and CaCl 2 solution at different concentrations to study the transport properties of different cations in the single conical nanopores respectively. The measured I–V data showed that the conical nanopores have rectified transportation of these cations at the applied voltage of between +2 V and −2 V. The rectification coefficient γ of the mono- and bivalent ions was determined in their solution of 0.0001–1 M measured at 1 V, the result showed that the rectification coefficient is dependent on the valence of the ions and the electrolyte solution. [ABSTRACT FROM AUTHOR]

Single-event-effects (SEEs) in integrated circuits (ICs) caused by galactic single ions are the major cause of anomalies for a spacecraft. The main strategies to decrease radiation failures for spacecraft are using SEEs less-sensitive devices and design radiation hardened ICs. High energy ion microbeam is one of the powerful tools to obtain spatial information of SEEs in ICs and to guide the radiation hardening design. The microbeam facility in the Institute of Modern Physics (IMP), Chinese Academy of Science (CAS) can meet both the liner energy transfer (LET) and ion range requirements for SEEs simulation experiments on ground. In order to study SEEs characteristics of ICs at this microbeam platform, a SEEs analysis system was developed. This system can target and irradiate ICs with single ions in micrometer-scale accuracy, meanwhile it acquires multi-channel SEE signals and maps the SEE sensitive regions online. A 4-Mbit NOR Flash memory was tested with this system using 2.2 GeV Kr ions, the radiation sensitive peripheral circuit regions for SEEs of 1 to 0 and 0 to 1 upset, multi-bit-upset and single event latchup have been obtained. [ABSTRACT FROM AUTHOR]