2024-03-29T07:07:42Z
https://nagoya.repo.nii.ac.jp/oai
oai:nagoya.repo.nii.ac.jp:00030460
2023-01-16T04:23:56Z
673:674:675
Nuclear emulsion with excellent long-term stability developed for cosmic-ray imaging
Nishio, Akira
101303
Morishima, Kunihiro
101304
Kuwabara, Ken-ichi
101305
Yoshida, Tetsuo
101306
Funakubo, Takeshi
101307
Kitagawa, Nobuko
101308
Kuno, Mitsuaki
101309
Manabe, Yuta
101310
Nakamura, Mitsuhiro
101311
Nuclear emulsion
Long-term stability
Latent image fading
Fog
Sensitivity degradation
Cosmic-ray imaging
Nuclear emulsion is a film-type charged particle track detector that uses the technology of silver halide photosensitive material. Because nuclear emulsion is compact and does not require an electric power source, it is suitable as a detector for cosmic-ray imaging (also called cosmic-ray muon radiography or muography) that requires outdoor observation. However, problems with the long-term stability and temperature tolerance of nuclear emulsion limit the observation periods, seasons and locations where it might be used. To enable long-term observation and outdoor use throughout the year, we investigated factors that affect the long-term characteristics of nuclear emulsion. The results of our experiments clearly showed that gelatin, additive chemicals, and packing material affect the long-term stability. Based on these results, we have developed a nuclear emulsion with excellent long-term stability. To confirm the properties of this newly developed nuclear emulsion, we examined the temperature dependence, and created an Arrhenius plot of the reaction rate. The prediction based on Arrhenius law showed that the Grain Density stayed at 25/100 μm or more for more than one year at 10 °C and 20 °C, and for 260 days at 30 °C; and the Fog Density stayed at 5/1000 μm^3 or less for more than one year at 10 °C and 20 °C, and for 270 days at 30 °C. This represents a new nuclear emulsion that is not limited by the observation period, season, and location. In fact, the developed stable nuclear emulsion is being used for cosmic-ray imaging observations in the pyramid of Khufu and is expected to be used for future cosmic-ray imaging observations and other elementary particle research.
ファイル公開日: 2022/06/21
journal article
Elsevier
2020-06-21
application/pdf
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
966
163850
0168-9002
https://nagoya.repo.nii.ac.jp/record/30460/files/revision20200305.pdf
eng
https://doi.org/10.1016/j.nima.2020.163850
© 2020. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/