Abstract

To recognize sub-micron-range low-energy tracks recorded in a super-fine-grained nuclear emulsion (Nano Imaging Tracker), an elliptical fitting method was devised to analyze anisotropic images taken by an optical microscope. We report on this newly developed method using a discrete Fourier transform and second-order moment analysis of the brightness distribution. We succeeded in lowering the ellipticity threshold, thereby improving the selection efficiency and angular resolution. Notably, the success of detecting carbon 30 keV tracks is the first such achievement in the world, where the incident direction of carbon 30 keV ions was determined with an accuracy of 41$^\circ$ and an efficiency of $1.7 \pm 0.1\%$.

Details

Title
Optical shape analysis based on discrete Fourier transform and second-order moment analysis of the brightness distribution for the detection of sub-micron range tracks in nuclear emulsion
Author
Umemoto, Atsuhiro 1 ; Naka, Tatsuhiro 2 ; Nakano, Toshiyuki 3 ; Kobayashi, Ryuta 1 ; Shiraishi, Takuya 4 ; Asada, Takashi 5 

 Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602, Japan 
 Toho University, 2-2-1 Miyama, Funabashi, Chiba, 274-8510, Japan; Kobayashi-Maskawa Institute, Nagoya University, Furo-cho, Nagoya, Aichi, 464-8601, Japan 
 Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602, Japan; Kobayashi-Maskawa Institute, Nagoya University, Furo-cho, Nagoya, Aichi, 464-8601, Japan 
 Toho University, 2-2-1 Miyama, Funabashi, Chiba, 274-8510, Japan 
 Laboratori Nazionali del Gran Sasso Via G. Acitelli, 22 67100 Assergi L’Aquila, Italy 
Publication year
2020
Publication date
Oct 2020
Publisher
Oxford University Press
e-ISSN
20503911
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
3171486753
Copyright
© The Author(s) 2020. Published by Oxford University Press on behalf of the Physical Society of Japan. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.