JAEA-Conf 2011-002 - 日本原子力研究開発機構

Neutron Yield [#/MeV/sr/ion]
10 0
10 -1
10 -2
10 -3
10 -4
10 -5
10 0
Emission angle: 0 0
Experiment
PHITS
FLUKA
10 1
10 2
Neutron Energy [MeV]
Fig 1. Thick-target neutron yields at the emission angle of 0 0
Neutron Yield [#/MeV/sr/ion]
10 0
10 -1
10 -2
10 -3
10 -4
10 -5
10 0
10 1
10 2
Neutron Energy [MeV]
Emission angle: 60 0
Experiment
PHITS
FLUKA
10 3
10 3
Neutron Yield [#/MeV/sr/ion]
10 0
10 -1
10 -2
10 -3
10 -4
10 -5
10 0
10 1
10 2
Neutron Energy [MeV]
Emission angle: 30 0
Experiment
PHITS
FLUKA
Fig 2. Thick-target neutron yields at the emission angle of 30 0
Neutron Yield [#/MeV/sr/ion]
10 0
10 -1
10 -2
10 -3
10 -4
10 -5
10 0
10 1
10 2
Neutron Energy [MeV]
Emission angle: 90 0
Fig 3. Thick-target neutron yields at the emission angle of 60 0 Fig 4. Thick-target neutron yields at the emission angle of 90 0
The neutron dose rates behind the concrete shield were calculated using the neutron spectra calculated with
PHITS and FLUKA codes. The evaluated Neutron Dose distributions behind of the concrete shield were shown in
the Figure 5 to Figure 8.
For the neutron source at the angle of 0 0 and 90 0 , the dose rates were under a factor of 1.2 and showed a same
trend. For the neutron source at the angle of 30 0 and 60 0 , the dose rates were under a factor of 1.4 but the dose rate
calculated from PHITS was higher than those from FLUKA after passing the concrete shield of 10
0 ~ 150 cm thick . This is due to the differences of the production of the high energy neutrons. The shape of the
neutron spectrum calculated by PHITS changed more hardly than those by FLUKA.
III. Conclusion
JAEA-Conf 2011-002
The simulations for C-12 ion beam with the energy of 400 MeV/n impinging on the target were performed
by using PHITS and FLUKA codes. The angular distributions of the secondary neutrons from the thick target
were compared with the measurement and the differences of the dose rate behind of the shield materials, concrete,
due to the neutron spectrum was evaluated. The thick target yield from this study were evaluated in the differences
under 40 % compared with measurement and the dose rates behind of the concrete shield were under a factor of
1.4. It will be expected that the use of the PHITS and FLUKA codes is reasonable for the heavy ion reactions and
shielding calculations consider a margin with a factor of 1.4 for the radiation shielding design, for the n-TOF
experimental room using heavy ion beam in the accelerator facility in Korea.
Experiment
PHITS
FLUKA
10 3
10 3