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A microbeam system was installed at Dynamitron laboratory at Tohoku University and is applicable to simultaneous in-air/in-vacuum PIXE, RBS, SE, and STIM analyses, and 3D µ-CT. Insufficient beam brightness of the source and field contamination of the microbeam line restricted spatial resolution. In order to improve the performance of Tohoku microbeam system, optimization and modification of the ion source and microbeam system were performed. By the modification of the system, the beam brightness of the system was increased to 1.0 pA·µm^-2·mrad^-2·MeV^-1 at the half divergence of 0.2 mrad. Considering the brightness and the magnification, obtainable target current will be 200 and 900 pA for beam spot sizes of 1.0 × 1.0 and 2.0 × 2.0 µm², respectively. The modification of the source meets both the lifetime and the performance. The parasitic field contamination of the system was reduced down to less than 0.5 % by replacing the beam scanner chamber and a part of beam duct. Both resolution and beam currents are sufficient for our applications of in-air/in-vacuum PIXE, RBS, SE, and STIM analyses and 3D PIXE-µ-CT.

The microbeam system at Tohoku University was upgraded to a triplet lens system aiming at applying to the analysis of sub-micron features. The triplet lens system has a higher demagnification than the existing doublet system. However, the introduction of the triplet system also resulted in larger chromatic and spherical aberration coefficients. To overcome these problems, the energy resolution of the accelerator was improved by developing a terminal voltage stabilization system. The energy resolution of the accelerator was improved to 1 × 10⁻⁵ ΔE/E, which resulted in an increase in the brightness of the beam. The beam brightness was 2.3 pA Δ μm⁻² Δ mrad⁻² Δ MeV⁻ and was higher in the central region. The effects of the increased chromatic and spherical aberration were mitigated by restricting the divergence angle without reducing the beam current. A beam spot size of 0.6 × 0.8 μm² was obtained with a beam current of 150 pA.

Previously, the generalized luminosity was defined and calculated for all incident channels based on an NLC e⁺e^- design. Alternatives were then considered to improve the differing beam-beam effects in the e^-e^-, eγ and γγ channels. Regardless of the channel, there was a large flux of outgoing, high energy photons that were produced from the beam-beam interaction e.g. beamstrahlung that needs to be disposed of and whose flux depended on . One approach to this problem is to consider it a resource and attempt to take advantage of it by disposing of these straight–ahead photons in more useful ways than simply dumping them. While there are many options for monitoring the luminosity, any method that allows feedback and optimization in real time and in a non-intercepting and non-interfering way during normal data taking is extremely important – especially if it provides other capabilities such as high resolution tuning of spot sizes and can be used for all incident channels without essential modifications to their setup. Our "pin-hole" camera appears to be such a device if it can be made to work with high energy photons in ways that are compatible with the many other constraints and demands on space around the interaction region. The basis for using this method is that it has, in principle, the inherent resolution and bandwidth to monitor the very small spot sizes and their stabilities that are required for very high, integrated luminosity. While there are many possible, simultaneous uses of these outgoing photon beams, we limit our discussion to a single, blind, proof-of-principle experiment that was done on the FFTB line at SLAC to certify the concept of a camera obscura for high energy photons.

Anodized aluminum (Al) and Al alloys have a wide range of applications. However, certain anodized finishings have relatively low hardness, dull appearance and/or poor corrosion resistance, which limited their applications. In this research, Al was first electropolished in a phosphoric acid-based solution, then anodized in a sulfuric acid-based solution under controlled processing parameters. The anodized specimen was then sealed by two-step sealing method. A systematic study including microstructure, surface morphology, hardness and corrosion resistance of these anodized films has been conducted. Results show that the hardness of this new anodized film was increased by a factor of 10 compared with the pure Al metal. Salt spray corrosion testing also demonstrated the greatly improved corrosion resistance. Unlike the traditional hard anodized Al which presents a dull-colored surface, this newly developed anodized Al alloy possesses a very bright and shiny surface with good hardness and corrosion resistance.

Fourth generation light sources based on high gain free electron lasers require production, acceleration and transport up to the undulator entrance of high brightness (low emittance, high peak current) electron bunches. Wake field effects in accelerating sections and in magnetic bunch compressors typically contribute to emittance degradation, and hence the design of the injector and its operation constitute the leading edge for high quality beam production and for the success of the future light sources. RF and DC guns, cathode materials, laser pulse shaping and sub-picosecond synchronization systems are evolving toward a mature technology to produce high quality and stable beams. Nevertheless, reduction of thermal emittance, damping of emittance oscillations and bunch compression are still the main issues and challenges for injector designs. With the advent of energy recovery linacs, superconducting RF guns have been also considered in many new projects as a possible electron source operating in CW mode. An overview of recent advancements and future perspectives of high performance electron injectors are presented in this article.

With the development of technology, more and more cities and highways are installing light reducing structures at the tunnel openings to improve traffic safety and reduce the “black hole effect” and low-angle sunlight glare effect. However, the existing scrims have poor road surface uniformity, bright and dark streaks and uneven road surface brightness, which can bring negative impact on driving. In order to balance the safety and comfort of tunnel light sheds, a new technique is proposed to reduce the negative effects of light sheds based on the multi-source effect of light diffusion panels. The results show that by arranging light diffusion panels on the top of the scrim, the daylight is fully diffused and then irradiated to the road surface under the scrim, avoiding the undesirable phenomenon caused by direct sunlight on the road surface. After the indoor test and numerical model analysis, the effectiveness of the technology is proved to be in compliance with the design specification, and the undesirable phenomena such as bright and dark streaks are avoided, thus ensuring the safety and comfort of traffic at the tunnel entrance. In addition, the average brightness of the road surface of the top arrangement of light diffusion panels is better than that of the two sides, and the light intensity distribution curve of No. 2 panel among the four light diffusion panels used in this paper is the best. The technology can also control the brightness level of the road surface under the shed through the area of light diffusion panels, thus reducing the carbon emission of the tunnel lighting system and achieving the unity of safety, comfort and low carbon environment protection.

The establishment of a Codebook background model in RGB color space results in high computational complexity, low segmentation quality and poor immunity power. We proposed the improved brightness range Codebook algorithm under YUV space to overcome the problem of irrational brightness range definition of the algorithm, as well as the background updating method which combined a two-layer Codebook model with a short-sliding window. Firstly, the Codebook background model was built under YUV color space based on the characteristics of luminance and chrominance separation. Secondly, the brightness range was redefined using the average of the Y component of the codeword to tackle the problem of the irrational brightness range definition of the background model. Lastly, a two-layer Codebook model and a short-sliding window were combined to update the background in the process of moving object detection in order to improve the antijamming capability. The experiments demonstrated that the improved brightness range can be updated gradually with background changes. Comparing with the original algorithm, this method can update the background effectively, and improve the detection accuracy.

Base on the growing technology of LED lighting which combined with intelligent control method in tunnel lighting. The performance of long working life, low consumption and good light stability will definitely become the future trend. Through reasonable lighting, not only to ensure the driver can obtain the quality of visual information, but also guarantee the comfortableness and safety during driving in the tunnel. This paper mainly focuses on the research about mathematical calculation model of highway tunnel lighting system. Base on the studies of lighting computational scheme, in order to determine the correct calculation method. The result can be applied to guidance for designing the tunnel lighting system.

Fourth generation light sources based on high gain free electron lasers require production, acceleration and transport up to the undulator entrance of high brightness (low emittance, high peak current) electron bunches. Wake field effects in accelerating sections and in magnetic bunch compressors typically contribute to emittance degradation, and hence the design of the injector and its operation constitute the leading edge for high quality beam production and for the success of the future light sources. RF and DC guns, cathode materials, laser pulse shaping and sub-picosecond synchronization systems are evolving toward a mature technology to produce high quality and stable beams. Nevertheless, reduction of thermal emittance, damping of emittance oscillations and bunch compression are still the main issues and challenges for injector designs. With the advent of energy recovery linacs, superconducting RF guns have been also considered in many new projects as a possible electron source operating in CW mode. An overview of recent advancements and future perspectives of high performance electron injectors are presented in this article.