日本大学生産工学部　研究報告A（理工系）第52巻第1号

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─ 1 ─１．序　　論ニュートリノ研究の進歩はめざましい。2015年ノーベル物理学賞で祝福されたスーパーカミオカンデによるニュートリノ振動の発見１）以来，多くのことがわかってきた。我々も参加したOPERA実験では，ミューニュートリノからタウニュートリノへの振動を，出現したタウニュートリノの検出により，確認することができた２）。今後は，物質優勢の宇宙創生の鍵を握ると言われるレプトンセクターにおけるCP対称性の破れなど，残されたニュートリノの謎に迫るため，精密実験の時代に入る。論　　文日本大学生産工学部研究報告Ａ2019年 ６ 月 第 52 巻 第 １ 号新型原子核乾板の大型現像処理環境の構築とその現像結果三角尚治＊，花岡佑哉＊＊，森元祐介＊＊＊，松尾友和＊＊＊，大島　仁＊＊＊＊，福田　努＊＊＊＊＊Construction of a Large-scale Facility to Process a New Type of Nuclear Emulsion Films and Its Results.Shoji MIKADO＊，Yuya HANAOKA＊＊，Yusuke MORIMOTO＊＊＊，Tomokazu MATSUO＊＊＊，Hitoshi OSHIMA＊＊＊＊，and Tsutomu FUKUDA＊＊＊＊＊Study of neutrino properties is one of the most important subjects in particle physics. Since the discovery of neutrino oscillation, much progress has been made in our understanding of neutrino properties in these two decades. More precise experiments by reducing the main source of systematic errors will be required to solve remaining mysteries. The J-PARC T60/NINJA experiment was designed to precisely measure the neutrino-nucleus cross sections in the 1 GeV energy region. The experiment utilizes a large amount of nuclear emulsion lms of a new type where the size and content of AgBr crystals can be chosen according to the aim of experiments. Hence we have newly constructed a large-scale facility to process the new type emulsion lms. By monitoring and controlling the temperature and humidity in the facility, we have succeeded in developing 318 large emulsion lms and later in swelling them. The thickness of the emulsion layers after the processing was controlled to be 70±3 μm. The detection efciency of penetrating particle tracks was found to be higher than 95%, for most of the lms. An important advantage of emulsion lms to detect and identify low-energy protons was conrmed. Furthermore some neutrino-nucleus interactions have already been found. Thus the facility have been veried to have sufcient capability to process such a large amount of new type emulsion lms properly.Keywords:Nuclear Emulsion, Development, Neutrino, Darkroom, Elementary Particle Physics　　　　＊日本大学生産工学部教養・基礎科学系准教授　　　＊＊日本大学生産工学部数理情報工学科４年　　＊＊＊東邦大学理学部科研費臨時職員　＊＊＊＊東邦大学大学院理学研究科博士後期課程３年＊＊＊＊＊名古屋大学高等研究院（理学研究科）YLC特任助教