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Sanami, Toshiya*; Iwamoto, Yosuke; Shigyo, Nobuhiro*; Hagiwara, Masayuki*; Lee, H.-S.*; Leveling, A.*; Vaziri, K.*; Boehnlein, D.*; Mokhov, N.*; Sakamoto, Yukio; et al.
Progress in Nuclear Science and Technology (Internet), 1, p.44 - 47, 2011/02
Muons become important particle for radiation safety design of high energy and intense accelerator since muons penetrate a thick shielding wall. In this study, the dose rate distributions around high intensity muon beam were measured at the muon alcoves and the bypass tunnel of Neutrinos at the Main Injector (NuMI) facility in Fermi National Accelerator Laboratory (Fermilab). The dosimeters of Luxel budges (OSL, CR39) and TLD budges (UD813PQ) were placed in the second, third and forth alcoves to measure muons, photons, and, thermal and fast neutrons. Neutrons and photons were measured in the bypass tunnel using a Bonner sphere and an ionization chamber. The spatial distribution of muons is calculated using MARS code. The results of dosimeters show same spatial distribution including attenuation along the beam line in comparison with the calculation results.
Yashima, Hiroshi*; Kasugai, Yoshimi; Matsuda, Norihiro; Matsumura, Hiroshi*; Iwase, Hiroshi*; Kinoshita, Norikazu*; Mokhov, N.*; Leveling, A.*; Boehnlein, D.*; Vaziri, K.*; et al.
Progress in Nuclear Science and Technology (Internet), 1, p.48 - 51, 2011/02
The shielding experiment was performed at the anti-proton production target station in Fermi National Accelerator Laboratory. Aluminum, Bismath, Niobium, Copper and Indium samples were placed behind the shields. After irradiation, induced activities of samples were measured by using HPGe detector. The spatial distribution of reaction rate of samples which were placed behind the iron and concrete shields were obtained. The measured data shows that the reaction rates on the outer surfaces of the iron and concrete shields increases toward the downstream of the target. The obtained reaction rates were also fitted to Moyer's formula, and the attenuation lengths for iron and concrete shields were obtained.
Hagiwara, Masayuki*; Sanami, Toshiya*; Iwamoto, Yosuke; Arakawa, Hiroyuki*; Shigyo, Nobuhiro*; Mokhov, N.*; Leveling, A.*; Boehnlein, D.*; Vaziri, K.*; Nakamura, Takashi*; et al.
Progress in Nuclear Science and Technology (Internet), 1, p.52 - 56, 2011/02
In pbar target station, the pulsed proton beam with the power of around 75 kW and the time structure of 1.6 
s pulse width and 2.2 s cycle time bombards the pbar production target and produces high instantaneous intensity neutron (burst neutron) fields. The duration of the burst neutrons, which is less than s, is very severe condition to measure neutron spectra with a conventional Bonner sphere technique with pulse readout electronics because of signal pile-up problem. In this study, we have developed a current readout Bonner sphere technique to measure neutron spectra in a burst neutron field. We have measured the neutron spectra on the pbar target and graphite dump. The neutron spectra obtained with the present technique show generally good agreements with the calculation results using MARS code except difference of the thermal neutron flux due to the geometrical problem.
Matsuda, Norihiro; Kasugai, Yoshimi; Matsumura, Hiroshi*; Yashima, Hiroshi*; Iwase, Hiroshi*; Kinoshita, Norikazu*; Sanami, Toshiya*; Mokhov, N.*; Leveling, A.*; Boehnlein, D.*; et al.
Progress in Nuclear Science and Technology (Internet), 1, p.57 - 60, 2011/02
The anti-proton (pbar) production target in Fermi National Accelerator Laboratory can be produced a wide variety of secondary particles including of anti-protons, by bombarding with protons accelerated to 120 GeV. The shielding experimental data, which was obtained around the pbar target, make possible to validate the accuracies of the general-purpose Monte Carlo simulation codes. In this paper, spatial distribution of reaction rates were calculated with two-dimensional (r-z) geometry simplified the real pbar target station using the PHITS, MARS and MCNPX code. These experimental data in iron shield were compared with the calculated data. The comparison for attenuation length of iron were good agreement between the experiments and calculations.
