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Our interests for years lay to investigate the reason why CR-39 polymer has such high sensitivity as plastic nuclear track detector(PNTD) on chemical structural aspects. We developed three PNTDs from three diacrylate compounds as monomers bearing different molecular length as well as different numbers of internal ether bonds. The polymer products obtained were colorless and transparent with 3-D molecular structures as CR-39 and different lattice each other. Our purpose of the current study was to investigate structural damages caused in newly prepared PNTD s and CR-39 by irradiation of Nitrogen ion (6 MeV/n, fluence of 5×10 11 cm-2). The structural damage by irradiation was analyzed by the magnitude of the relative absorbance of specific functional groups such as ester, C-O, ether and C-H bonds by means of FT-IR (ATR) method. The correlation between the relative absorbance and the molecular length of the monomers were discussed.

Chemical modification along ion tracks in Poly (allyl diglycol carbonate), PADC, films has been studied by means of Fourier transform infrared (FT-IR) spectrometry, which has exposed to protons and heavy ions in air. Chemical damage parameters, namely, radial size of the track core, in which the considered chemical groups are lost, damage density, which is the number of losses of considered functional groups per unit length of tracks, and radiation chemical yields, G values, for each group are evaluated as a function of the stopping power. The radiation chemical yields are higher at lower stopping powers for each ion and greater with increasing charge at the same stopping powers. Secondary electrons with higher energy should play a significant role to increase the yields by producing damage at a relatively distant place from the ion trajectories.

More than 15 years have been passed since the discovery of the sensitization effect by CO2 treatment on PADC detectors. The effect has strong relation with the dissolving process of CO2 into etching solution through the renewing surface of the detector during etching. In this study, releasing behavior of CO2 from the treated PADC is examined by means of FT-IR spectrometry and discussed based on the diffusion theory of Fick. We have succeeded to produce bending-etch pits, in which the pit walls have differed slope, depending on the applied etching conditions with the CO2 treatment or not.

Anomalous behavior has been observed on the contact angle of water droplets on PADC, poly (allyl diglycol carbonate), nuclear track detectors which is exposed to proton beams. The angel reaches to the maximum value of 89 degree from the original value of 70 degree without the exposure at a fluence of 1.0x1013 ions/cm2.In the case of heavy ion irradiations by He, C and Xe ions, the angle decreases with increasing the fluence. Similar results have been observed for gamma irradiations, UV irradiations and the exposure to corona discharge. In order to evaluate the surface structure, XPS observations were made for PADC, in which X ray irradiation are simultaneously conducted. The polyethylene like network is more radiation tolerance than the ether and carbonate ester bonds which are in the repeat units. The observed anomalous behavior of the track angle is discussed from the point of views of track core size and spatial distribution on the PADC.

Chemical modification along ion tracks in PADC, poly (allyl diglycol carbonate), films has been studied by means of FT-IR spectrometry, which were exposed to proton and heavy ions. The damage density for loss of carbonate ester bonds per unit length of tracks were assessed for each ion, as a function of stopping power. The G values and the corresponding effective track core radii were also evaluated. It is in the tendency that G value increases gradually with stopping power of heavy ions from C to Xe ion. On the contrary to this, a reverse tendency was found for proton, He, and high energy C ions.

Chemical modification along heavy ion tracks in bisphenol A polycarbonate has been studied by means of FT-IR spectrometry. The damage density for the loss of carbonyl bonds, phenyl rings and methyl bonds per unit length of tracks were assessed for He, C, Ne, Ar, Fe and Xe ions, as a function of stopping power. The G-values and the corresponding effective track core radii for each group were also evaluated. The tracks had three different zones. The center lost all three functional groups, which was surrounded by the second zone where the carbonyl and phenyl rings were damaged. The outer zone lost only the carbonyl bonds. Breaking of more than two neighbor carbonate ester bonds would produce the latent tracks, which are able to be developed by following chemical etching.

大気球シンポジウム 平成18年度（2007年1月15-16日. 宇宙航空研究開発機構宇宙科学研究本部 (JAXA)(ISAS)）, 相模原市, 神奈川県), Balloon Symposium 2006 (January 15-16, 2007. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 著者人数: 17名, 資料番号: SA6000090040

大気球シンポジウム 平成18年度（2007年1月15-16日. 宇宙航空研究開発機構宇宙科学研究本部 (JAXA)(ISAS)）, 相模原市, 神奈川県), Balloon Symposium 2006 (January 15-16, 2007. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 著者人数: 17名, 資料番号: SA6000090041

第62回応用物理学会春季学術講演会(2015年3月11日-14日. 東海大学湘南キャンパス), 平塚市, 神奈川県, 資料番号: AC1500090000, レポート番号: 11p-A19-2

Recently we have confirmed the scission of ether bonds occurred in the almost same efficiency to CO_2 gas formation along ion track in CR-39 detector. This means that part between two carbonate ester bonds in each repeat unit can be segmented into at least 4 gaseous molecules including CO_2. We think that this kind of segmentation should be a key phenomenon to produce latent tracks in CR-39. In order to construct the quantitative track formation model in CR-39, we have assessed G-value for the scission at carbonate ester bonds in bisphenol A polycarbonate films (Macrofol KG). PC films were exposed to C (28MeV), Ne (47MeV), Ar (103MeV) and Fe (137MeV) ions in air. The G-values for the destroy of carbonate ester bonds were found to be 2.2, 2.5, 3.0 and 2.8 (C=O destroy/100eV) for C, Ne, Ar and Fe ion, respectively.

The radial core size of tracks in CR-39 plastics has been determined for several heavy ions, O (8.6MeV), Ne (18.8MeV), Si (27MeV), Ar (35MeV), Fe (80MeV), I (200MeV), Xe (240MeV) and Au (250MeV) ions, through the surface observation using AFM. The core radii were assessed from the growth behavior of minute etch-pits within 1 min etchings. These were derived from each intersection of the extrapolated line, fitted to each growth curve of etch pit radius. Based on the radial dose distribution model, local dose around the core radii of each ion from AFM method were assessed. These calculations indicate that the track core is formed at region where the local dose is greater than a hundred kGy.

大気球シンポジウム 平成16年度（2004年12月2-3日. 宇宙航空研究開発機構宇宙科学研究本部 (JAXA)(ISAS)）, 相模原市, 神奈川県), Balloon Symposium 2004 (December 2-3, 2004. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 著者人数: 12名, 資料番号: SA6000091041

大気球シンポジウム 平成16年度（2004年12月2-3日. 宇宙航空研究開発機構宇宙科学研究本部 (JAXA)(ISAS)）, 相模原市, 神奈川県), Balloon Symposium 2004 (December 2-3, 2004. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 著者人数: 12名, 資料番号: SA6000091040

資料番号: AC1200011000

現在我々は, イメージングプレート(IP)を超重粒子検出器として応用すべく, IPの基礎実験を行っている。本文では, 放射線医学総合研究所での重粒子照射実験と山形大学でのアルファー線照射実験を基に, IPのフェーディング効果とIPによる重粒子のdE/dx決定方法を述べる。, We are investigating basic characteristics of an Imaging Plate to develop new type of ultra heavy particle detector. In this paper, we describe the fading characteristics of the Imaging Plate (IP) and the method of determination of dE/dx for heavy particles in use of the IP, based on the experiments of the irradiation with heavy particles by the accelerator (HIMAC) in NIRS and with α-rays in Yamagata University., 資料番号: SA0167161000

第4回太陽・地球・生態系と時間治療研究会 (2003年11月8日. サンケイプラザ), 東京都, 資料番号: AC1200035000