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Yamaki, Tetsuya*; Nuryanthi, N.*; Kitamura, Akane; Koshikawa, Hiroshi*; Sawada, Shinichi*; Voss, K.-O.*; Severin, D.*; Tautmann, C.*
Nuclear Instruments and Methods in Physics Research B, 435, p.162 - 168, 2018/11
Times Cited Count：8 Percentile：62.29(Instruments & Instrumentation)We used individual single-ion tracks in fluoropolymers with diameters of tens to hundreds of nanometers; chemical etching and ion-track grafting enabled us to develop ion-track and proton-conductive membranes, respectively. In the ion-track membranes of PVDF, strongly-LET-dependent etching was found, so the pore shape as well as the size was exclusively controlled by the track structures. We performed the ion-track grafting of styrene into ETFE to develop nanostructure-controlled proton exchange membranes (PEMs) for applications in PEM fuel cells. Our ion beam technology to develop fluoropolymer-based nanostructures has the potential to apply in the field of filtration processes and fuel cell devices. This would make it possible to provide new microfiltration technology for water treatment, sterilization, petroleum refining and dairy processing.
Yamaki, Tetsuya*; Goto, Mitsuaki*; Sawada, Shinichi*; Koshikawa, Hiroshi*; Kitamura, Akane; Higa, Mitsuru*
QST-M-8; QST Takasaki Annual Report 2016, P. 35, 2018/03
We prepared ion exchange membranes by a heavy-ion-track grafting method, and then used them for seawater concentration process. Both the water uptake and resistance were lower for our ion-track grafted membranes than for the conventional 
-ray-grafted membranes. The results would be because local and high-density energy deposition due to the ion beam enabled us to control the membrane structure in a nanometer scale. We demonstrate our membranes are suitable for this application.
Furuya, Kazuyuki; Wakai, Eiichi; Ando, Masami; Sawai, Tomotsugu; Nakamura, Kazuyuki; Takeuchi, Hiroshi; Iwabuchi, Akira*
Journal of Nuclear Materials, 307-311(Part1), p.289 - 292, 2002/12
Times Cited Count：7 Percentile：44.29(Materials Science, Multidisciplinary)no abstracts in English
Okayasu, Satoru; Hojo, Kiichi; Ishida, Takekazu*
JAERI-Review 2002-018, 118 Pages, 2002/09
JAERI-Review-2002-018.pdf:10.38MB
no abstracts in English
Hojo, Kiichi; Okayasu, Satoru; Sasase, Masato; Ishida, Takekazu*
JAERI-Review 2001-008, 150 Pages, 2001/03
JAERI-Review-2001-008.pdf:20.63MB
no abstracts in English
Tanaka, Ryuichi; Yotsumoto, Keiichi; Watanabe, Hiromasa
Radioisotopes, 45(3), p.213 - 220, 1996/03
no abstracts in English
Ge-Ga source with high production efficiency by an improved metal galium targetMaekawa, Masaki; Zhou, K.*; Fukaya, Yuki; Zhang, H.; Li, H.; Kawasuso, Atsuo
no journal, ,
no abstracts in English
Koshikawa, Hiroshi; Asano, Masaharu*; Yamaki, Tetsuya; Maekawa, Yasunari
no journal, ,
We investigated track etch rates (V
) of polyimide irradiated with different ions by a conductivity technique and their LET dependence. Both of 12 and 25 
m thick films were irradiated with 450 MeV 
Xe, 250 MeV 
Ar and 75 MeV 
Ne and then were etched with a sodium hypochlorite solution. The conductometric analysis involves recording electric conductance of the etchant across the film during the etching time. When the etched pores from both sides of the film made contact with each other, the conductance suddenly increased to find the breakthrough time (T
). A V value was obtained by dividing the half thickness of the films by T. The Xe ions with the highest LET of 12 MeV/m gave ca. 20 times higher V than the Ne ions. The change in V for the different beams is ascribed to an LET effect by considering that the bombardment with high-LET ions produces more severe molecular damage in each track.
Ueda, Daisuke*; Konishi, Suzuka*; Minagawa, Hideaki*; Hirade, Tetsuya; Tsuchida, Hidetsugu*
no journal, ,
Damaged conditions under irradiation such as ion beams irradiation are transient and unstable. Understanding of this transient damage state is important to clarify the process from damage generation to stabilization. We are developing Age-MOmentum Correlation (AMOC) measurement system by 
- coincident measurement to investigate the triplet positronium (o-Ps) reactions as a probe of reactive species. From the correlation between "positron annihilation time" and "momentum of electron / positron at pair annihilation" obtained by AMOC measurement, it is possible to investigate the process of o-Ps reactions. We report on AMOC measurement system newly constructed by digital method.
- based AMOC measurement systemKonishi, Suzuka*; Ueda, Daisuke*; Xu, Q.*; Hirade, Tetsuya; Tsuchida, Hidetsugu*
no journal, ,
In order to elucidate the transient damage state by ion beam etc., positron annihilation lifetime - momentum correlation (Age-MOmentum Correlation: AMOC) apparatus by - simultaneous measurement is newly constructed by the digital method. In this study, we investigated the effect of -irradiation of polystyrene using the AMOC apparatus. As a result, we obtained that the S parameter near 1 ns decreases corresponding to the increase of damage amount.
Konishi, Suzuka*; Minagawa, Hideaki*; Majima, Takuya*; Imai, Makoto*; Saito, Manabu*; Hirade, Tetsuya; Tsuchida, Hidetsugu*
no journal, ,
To clarify the damage behavior under ion irradiation in quartz glass, Age-Momentum Correlation measurement that is a coincidence measurement of positron annihilation lifetime and annihilation gamma ray Doppler broadening was performed under 2 MeV proton irradiation. From the change in momentum distribution of electrons involved in positron annihilation in voids of the quartz glass, flux dependence of damage behavior could be detected.
