Synchrotron-radiation-based Mssbauer spectroscopy

Seto, Makoto; Masuda, Ryo; Higashitaniguchi, Satoshi*; Kitao, Shinji*; Kobayashi, Yasuhiro*; Inaba, Chika*; Mitsui, Takaya; Yoda, Yoshitaka*

Physical Review Letters, 102(21), p.217602_1 - 217602_4, 2009/05

https://doi.org/10.1103/PhysRevLett.102.217602

We have developed a new method that yields Mssbauer absorption spectra using synchrotron radiation (SR); this method is applicable for almost all Mssbauer nuclides including those that cannot be measured by previous methods using radioisotope (RI) sources. The Mssbauer spectrum of the 68.752 keV excited state of Ge, which cannot be measured using a RI source, was measured using SR. Our results show that this method can be used to perform advanced Mssbauer spectroscopy measurements owing to the excellent features of SR.

Research on the Hydrogeological and Geochemical Conditions at the Coastal Area and Submarine Formations

Tokunaga, Tomochika*; Taniguchi, Makoto*; Shimada, Jun*; Zhang, J.*; Inaba, Kaoru; Saegusa, Hiromitsu; Iwatsuki, Teruki

JNC TY7400 2003-003, 142 Pages, 2003/05

JNC-TY7400-2003-003.pdf:6.85MB

One of the major concerns for the high-level radioactive waste disposal is the possibility of the radionuclides to reach biosphere by groundwater flow. Recent research results have shown that the fresh groundwater discharge from subsea formations are widespread phenomena, thus, it is necessary to evaluate the submarine groundwater discharge as possible pathways of contaminant discharge towards the biosphere. It is also important to unravel the groundwater flow and associated material transport at the coastal area and subsea formations. To better understand the groundwater flow processes and the submarine groundwater discharge, we have conducted the hydrological, hydrogeological, geochemical, and numerical modeling studies at the Kurobe alluvial fan and its offshore, Toyama Prefecture, Japan. In this report, the results of the following research activities are presented:1)Development and application of a method to detect the locations of the submarine groundwater discharge.2)Development and application of a method to collect uncontaminated groundwater samples from subesa formations.3)Measurements of submarine groundwater dischange fluxes by automated seepage meter.4)Hydrological and geochemical studies for groundwater flow at the coastal area.5)Geochemical studied to understand sources of fresh submarine groundwater discharge.6)Extamination of groundwater flow and submarine groundwater discharge using methane concentration and carbon isotope ratio.7)Numerical modeling studies for coastal groundwater flow system.