Promotion of the project for directional dark matter search with high resolution nuclear emulsion

本研究的目的是利用该探测器对暗物质进行定向搜索，该探测器可以作为大质量探测器工作。为此，我们提出了非常高分辨率的核乳液，并开始了该技术的研发。在本课题中，本课题的研究代表以核心人物的身份推动了课题的发展，并推进了实际应用。在探测器本身的发展方面，我们成功地将构成核乳剂的卤化银晶体微细化到20 nm的尺寸，该技术使生产过程中各种条件下的生产更加稳定。构建了基于光学显微镜的自动读出系统，实现了对预期为暗物质信号的亚微米径迹的自动读出。用中子后坐力信号对该系统进行了验证。同时，我们开发了用于SPring-8候选信号最终确认的x射线显微镜系统，并将该系统投入实际应用。通过这些研发，我们构建了从探测器生产到数据分析的系统流程，并可以进入试运行阶段。

This research is for directional dark matter searchwith the detector which can work as large mass detector. To do that, we proposed the very high resolution nuclear emulsion, and started R&D of the technology. In this subject, representative of this research promoted the project by being central figure and advanced the practical application. In terms of development of detector itself, we succeeded the micronization to 20 nm sizes for silver halide crystals constituting the nuclear emulsion, and its technology enabled more stable production under various conditions in production processes. Also, automatic read-out system based on optical microscope was constructed, and the submicron tracks expected as dark matter signal could be read out automatically. This system demonstrated by neutron recoil signal. Simultaneously, we developedthe X-ray microscope system for final confirmation of candidate signals in SPring-8, and this system was turned into the practical use.By these R&D, we constructed the procession of system from detector production to data analysis, and we can go to the phase of test run.