Digital Archives for Nuclear Emulsion Data

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K03885
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 15020:Experimental studies related to particle-, nuclear-, cosmic ray and astro-physics
• Research Institution: Aichi University of Education
• Principal Investigator: Kodama Koichi 愛知教育大学, 教育学部, 教授 (70211901)
• Co-Investigator(Kenkyū-buntansha): 市村 雅一 弘前大学, 理工学研究科, 教授 (20232415)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: エマルション / 原子核乾板 / アーカイブス / 宇宙線 / 気球実験 / 加速器実験 / ニュートリノ

Outline of Final Research Achievements

Digital archives for nuclear emulsion data of past physics experiments were studied. Nuclear emulsion is a tracking device with excellent spatial resolution of sub-micron and have been playing an important role in physics. We are succeeding to develop fast read-out system for tracks in emulsion and its latest version (HTS) is achieving a speed of 2000m2/year. In past experiments, a quite limited fraction of emulsion volume ( probably <1% ) had been analyzed due to lack of analysis power and the rest was left un-analyzed. HTS could provide us enough power to analyze all tracks recorded in them. DONUT is an experiment that had been succeeded to observe tau neutrino charged current interactions for the first time in the world. Module #1 of DONUT was successfully read out and it will be a part of our archives. A part of JACEE-13’s emulsion plates, exposed in Antarctic circumpolar flight, was also read out. Those archived data could be used for educational purposes for students.

Free Research Field

素粒子物理学実験

Academic Significance and Societal Importance of the Research Achievements

原子核乾板はサブミクロンの３次元位置分解能を持つ素粒子検出器であり、タウニュートリノの研究などにおいて大きな役割を果たしてきたが、その解析は、顕微鏡を使う時間と手間のかかるものであった。我々はこの解析の自動化を進め、現行の装置ＨＴＳは、過去の加速器・気球実験での総乾板面積にほぼ匹敵する、年間読出し面積２０００㎡に到達しつつある。これら過去の実験では、実際に読み出した乾板面積は全体の１％に満たず、記録された膨大な飛跡情報のごく一部を活用したに過ぎない。本研究は、これら過去の実験の乾板に記録された全飛跡をＨＴＳで読み出して共有し、原子核乾板のミニマムバイアス解析を行おうとする世界初の試みである。