Hydrogen analysis for granite using proton-proton elastic recoil coincidence spectrometry.
In an effort to develop DS02, a new radiation dosimetry system for the atomic bomb survivors of Hiroshima and Nagasaki, measurements of neutron-induced activities have provided valuable information to reconstruct the radiation situation at the time of the bombings. In Hiroshima, the depth profile of (152)Eu activity measured in a granite pillar of the Motoyasu Bridge (128 m from the hypocenter) was compared with that calculated using the DS02 methodology. For calculation of the (152)Eu production due to the thermal-neutron activation reaction, (151)Eu(n,gamma)(152)Eu, information on the hydrogen content in granite is important because the transport and slowing-down process of neutrons penetrating into the pillar is strongly affected by collisions with the protons of hydrogen. In this study, proton-proton elastic recoil coincidence spectrometry has been used to deduce the proton density in the Motoyasu pillar granite. Slices of granite samples were irradiated by a 20 MeV proton beam, and the energies of scattered and recoil protons were measured with a coincidence method. The water concentration in the pillar granite was evaluated to be 0.30 +/- 0.07%wt. This result is consistent with earlier data on adsorptive water (II) and bound water obtained by the Karl Fisher method.
Komatsubara
T
T
Tandem Accelerator Complex, Research Facility Center for Science and Technology, University of Tsukuba, Tsukuba, Ibaraki, 305-8577, Japan. komatsubara@tac.tsukuba.ac.jp
Sasa
K
K
Ohshima
H
H
Kimura
H
H
Tajima
Y
Y
Takahashi
T
T
Ishii
S
S
Yamato
Y
Y
Kurosawa
M
M
D006859:Hydrogen / Q000032:analysis*; D007564:Japan; D009689:Nuclear Warfare; D012822:Silicon Dioxide / Q000032:analysis*; D013057:Spectrum Analysis / Q000379:methods*
C007886:granite; D012822:Silicon Dioxide; D006859:Hydrogen