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ladderUeda, Hiroshi*; Onoda, Shigeki*; Yamaguchi, Yasuhiro*; Kimura, Tsuyoshi*; Yoshizawa, Daichi*; Morioka, Toshiaki*; Hagiwara, Masayuki*; Hagihara, Masato*; Soda, Minoru*; Masuda, Takatsugu*; et al.
Physical Review B, 101(14), p.140408_1 - 140408_6, 2020/04
Times Cited Count：4 Percentile：26.53(Materials Science, Multidisciplinary)Itashiki, Yutaro*; Imabayashi, Yoichi*; Shigyo, Nobuhiro*; Uozumi, Yusuke*; Satoh, Daiki; Kajimoto, Tsuyoshi*; Sanami, Toshiya*; Koba, Yusuke*; Matsufuji, Naruhiro*
Journal of Radiation Protection and Research, 41(4), p.344 - 349, 2016/12
Carbon ion therapy has achieved satisfactory results because of high curability and minimally invasiveness. However, patients have a risk to get a secondary cancer. In order to estimate the risk, it is essential to understand particle transportation and nuclear reactions in the patient's body. The particle transport Monte Carlo simulation code is a useful tool to understand them. Since the code validation for heavy ion incident reactions is not enough, the experimental data of the elementary reaction processes is needed. We measured neutron production double-differential cross-sections (DDXs) on a carbon bombarded with 430 MeV/nucleon carbon beam which is a possible candidate of future therapy beam. The experiment was performed at PH2 beam line of the HIMAC of National Institute of Radiological Sciences. The 430 MeV/nucleon carbon beam was irradiated on a 5 cm 
5 cm 1 cm graphite target rotated 45
to the beam axis. The beam intensity was set to 10
particles / spill. A 0.5 mm thick NE102A plastic scintillator was placed to monitor the beam intensity. Neutrons produced in the target were measured with two sizes of NE213 liquid organic scintillators located at six angles of 15, 30, 45, 60, 75, and 90. The 5.08 cm long one was used to obtain the neutron spectra from 1 MeV to 10 MeV and the 12.7 cm long one was used above 5 MeV. The 2 mm thick NE102A plastic scintillators to discriminate charged particles were set in front of the neutron detectors. The kinetic energies of neutrons were determined by the time-of-flight (TOF) method. Background neutrons were estimated by a measurement with iron shadow bars between the target and each neutron detector. An electronic circuit for data acquisition consisted of NIM and CAMAC modules. The experimental data was compared with calculated results obtained by Monte Carlo simulation codes as PHITS. The PHITS code reproduced the experimental data well.
Satoh, Daiki; Kajimoto, Tsuyoshi*; Shigyo, Nobuhiro*; Itashiki, Yutaro*; Imabayashi, Yoichi*; Koba, Yusuke*; Matsufuji, Naruhiro*; Sanami, Toshiya*; Nakao, Noriaki*; Uozumi, Yusuke*
Nuclear Instruments and Methods in Physics Research B, 387, p.10 - 19, 2016/11
Times Cited Count：3 Percentile：28.28(Instruments & Instrumentation)Double-differential neutron yields from a water phantom bombarded with 290-MeV/nucleon and 430-MeV/nucleon carbon ions were measured at emission angles of 15, 30, 45, 60, 75, and 90 using the neutron-detection system constituting of liquid organic scintillators. The angular distributions of neutron yields and effective doses around the phantom were obtained by integrating the double-differential neutron yields and applying the fluence-to-effective dose conversion coefficients. The experimental data were compared with results of the Monte-Carlo simulation code PHITS. The PHITS results showed good agreement with the measured data. From the results, we concluded that the PHITS simulation is applicable to the dose estimation at carbon-therapy facilities.
Shigyo, Nobuhiro*; Uozumi, Yusuke*; Imabayashi, Yoichi*; Itashiki, Yutaro*; Satoh, Daiki; Kajimoto, Tsuyoshi*; Sanami, Toshiya*; Koba, Yusuke*; Takada, Masashi*; Matsufuji, Naruhiro*; et al.
JAEA-Conf 2014-002, p.81 - 87, 2015/02
Cancer therapy using heavy ion beam has been adopted as highly advanced medical treatment by reason of its clinical advantages. It has become more important to estimate the risk of secondary cancer from recent survey. During treatment, secondary particles such as neutrons and -rays are producedby heavy ion induced nuclear reactions in a patient body as well as beam delivery apparatuses. For the risk assessment of secondary cancer, it is essential to know contribution of secondary neutrons by extra dose to organs in the vicinity of the irradiated tumor because the secondary neutron has a long flight path length and gives undesired dose to normal tissues in a wide volume. The experimental data of neutron energy spectra are required for dose estimations with high accuracy. Especially, precise data around neutron energy of 1 MeV is required because neutron of the energy region has a large relative biological eectiveness. Estimation of the secondary neutron yield data is important for estimation of radiation safety on both of workers and public in treatment facilities.
Kajimoto, Tsuyoshi*; Hashiguchi, Taro*; Shigyo, Nobuhiro*; Satoh, Daiki; Uozumi, Yusuke*; Song, T. Y.*; Lee, C. W.*; Kim, J. W.*; Yang, S. C.*; Koba, Yusuke*; et al.
JAEA-Conf 2014-002, p.127 - 132, 2015/02
Particle transport Monte Carlo codes such as PHITS, FLUKA and so on are used for radiation safety design of high energy accelerators. The validity of code is confirmed by comparison with many experimental data. In this study, we report proton, deuteron, and triton production double differential cross sections (DDXs) from a graphite target by 290 MeV/nucleon Ar ions. The measured spectra are compared with those calculated by PHITS and FLUKA codes.
Kajimoto, Tsuyoshi*; Shigyo, Nobuhiro*; Sanami, Toshiya*; Iwamoto, Yosuke; Hagiwara, Masayuki*; Lee, H. S.*; Soha, A.*; Ramberg, E.*; Coleman, R.*; Jensen, D.*; et al.
Nuclear Instruments and Methods in Physics Research B, 337, p.68 - 77, 2014/10
Times Cited Count：5 Percentile：38.03(Instruments & Instrumentation)The energy spectra of neutrons were measured by a time-of-flight method for 120 GeV protons on thick graphite, aluminum, copper, and tungsten targets with an NE213 scintillator at the Fermilab Test Beam Facility. Neutron energy spectra were obtained between 25 and 3000 MeV at emission angles of 30, 45, 120, and 150. The spectra were parameterized as neutron emissions from three moving sources and then compared with theoretical spectra calculated by PHITS and FLUKA codes. The yields of the theoretical spectra were substantially underestimated compared with the yields of measured spectra. The integrated neutron yields from 25 to 3000 MeV calculated with PHITS code were 16-36% of the experimental yields and those calculated with FLUKA code were 26-57% of the experimental yields for all targets and emission angles.
Uozumi, Yusuke*; Shigyo, Nobuhiro*; Uehara, Haruhiko*; Nishizawa, Tomoya*; Mizuno, Takafumi*; Satoh, Daiki; Sanami, Toshiya*; Koba, Yusuke*; Takada, Masashi*; Matsufuji, Naruhiro*; et al.
HIMAC-140, p.234 - 235, 2013/08
In the heavy-ion radiotherapy, considerable discussion has been attracted regarding the potential for second cancer induction by secondary neutrons produced from the primary heavy-ion fragmentation. We have started new measurements at 100 MeV/u to investigate the neutron production by heavy ions decelerating in a patient body.
and 90 bombarded with 120-GeV protonsIwamoto, Yosuke; Sanami, Toshiya*; Kajimoto, Tsuyoshi*; Shigyo, Nobuhiro*; Hagiwara, Masayuki*; Lee, H. S.*; Soha, A.*; Ramberg, E.*; Coleman, R.*; Jensen, D.*; et al.
Progress in Nuclear Science and Technology (Internet), 3, p.65 - 68, 2012/10
Neutron energy spectra at 15 and 90 produced from carbon, aluminum, copper and tungsten targets bombarded with 120-GeV protons were measured at Fermilab Test Beam Facility (FTBF) for the validation of simulation codes. The target thicknesses were 60 cm for graphite, 50 cm for aluminum, 20, 40, and 60 cm for copper and 10 cm for tungsten, respectively. The neutron time-of-flight measurements were performed using an NE213 organic liquid scintillator at 5.2 m for 90 and 8.0 m for 15 measuring from the center of the target to the surface of the detector. The raw signals (waveforms) obtained from photomultiplier tubes were recorded using the 10 bit digitizer (Agilent-acqiris DC282) with 0.5 ns sampling and 500 ns duration. To compare the experimental results, Monte Carlo calculations with the PHITS, MARS and FLUKA codes were performed. It was found that these calculated results underestimate the experimental results in the whole energy range.
Uozumi, Yusuke*; Shigyo, Nobuhiro*; Kajimoto, Tsuyoshi*; Hirabayashi, Keiichi*; Uehara, Haruhiko*; Nishizawa, Tomoya*; Satoh, Daiki; Sanami, Toshiya*; Koba, Yusuke*; Takada, Masashi*; et al.
HIMAC-138, p.237 - 238, 2012/08
In the heavy-ion radiotherapy, considerable discussion has been attracted regarding the potential for second cancer induction by secondary neutrons produced from the primary heavy-ion fragmentation. It is important to measure energy-angle double-differential cross sections (DDXs) of neutron- and photon-productions in heavy-ion nuclear reactions. Since it is notoriously hard to measure the spectral cross sections of neutrons in an energy range of around 1 MeV where the RBE value reaches at its maximum. In the project by last year, experiments were carried out at the synchrotron HIMAC of NIRS, Japan. The beams were 
C and 
O of 290 MeV/u and bombarded a carbon target. In measurements of neutrons and photons were used liquid scintillator detectors of 5" and 2". We have succeeded to lower the neutron energy threshold down to 0.6 MeV. The present results for neutron productions are in reasonable agreements with PHITS. Since our goal in technical aspects has been fulfilled, measurements will be continued for other reactions.
Uozumi, Yusuke*; Shigyo, Nobuhiro*; Kajimoto, Tsuyoshi*; Moriguchi, Daisuke*; Ueyama, Masahiko*; Yoshioka, Masakatsu*; Satoh, Daiki; Sanami, Toshiya*; Koba, Yusuke*; Takada, Masashi*; et al.
HIMAC-136, p.248 - 249, 2011/11
no abstracts in English
Satoh, Daiki; Moriguchi, Daisuke*; Kajimoto, Tsuyoshi*; Koba, Yusuke*; Nakamura, Yasuhiro*; Shigyo, Nobuhiro*; Ueyama, Masahiko*; Uozumi, Yusuke*; Yoshioka, Masakatsu*; Matsufuji, Naruhiro*; et al.
Journal of the Korean Physical Society, 59(2), p.1741 - 1744, 2011/08
Times Cited Count：3 Percentile：27.54(Physics, Multidisciplinary)The data of neutron production from heavy-ion interactions are of great importance for the dose assessment in heavy-ion therapy. We have already evaluated the data of neutron production for thick targets, in which the incident heavy ions completely stop, by the measurements and the reevaluation of the existing data reported by Kurosawa et al. As a next step of the research, we plan to evaluate the neutron-production cross-section data for thin targets. These data are useful to understand the mechanism of heavy-ion interaction, and improve the reaction model in particle transport codes. The previously reported cross-section data by Iwata et al. were revised by using a new set of neutron-detection efficiency values calculated with SCINFUL-QMD code. While the original data gave the larger values than the predictions of particle transport codes above 200 MeV due to the underestimation of the efficiencies, it was improved by this revision. In addition, we have started the new cross-section measurements at HIMAC. All the data of neutron-production cross sections were compared with the predictions of particle transport codes.
Satoh, Daiki; Moriguchi, Daisuke*; Kajimoto, Tsuyoshi*; Uehara, Haruhiko*; Shigyo, Nobuhiro*; Ueyama, Masahiko*; Yoshioka, Masakatsu*; Uozumi, Yusuke*; Sanami, Toshiya*; Koba, Yusuke*; et al.
Nuclear Instruments and Methods in Physics Research A, 644(1), p.59 - 67, 2011/07
Times Cited Count：18 Percentile：77.43(Instruments & Instrumentation)Neutron-production double-differential cross sections on carbon-carbon and oxygen-carbon reactions with incident heavy-ion energy of 290 MeV/nucleon were measured by time-of-flight method using liquid organic scintillators. By use of a detection system specialized for low-energy neutrons, the cross sections were obtained in a wide energy region from several hundred MeV down to 0.6 MeV for the oxygen-ion incidences. The experimental data were compared with the calculation results using the Monte-Carlo simulation code, PHITS. The PHITS results gave an overall agreement with the measured data within a factor of two.
Watanabe, Takehito*; Arakawa, Hiroyuki*; Kajimoto, Tsuyoshi*; Iwamoto, Yosuke; Satoh, Daiki; Kunieda, Satoshi; Noda, Shusaku*; Shigyo, Nobuhiro*; Ishibashi, Kenji*; Nakamura, Takashi*; et al.
Nuclear Instruments and Methods in Physics Research A, 587(1), p.20 - 28, 2008/03
Times Cited Count：1 Percentile：13.75(Instruments & Instrumentation)We have developed a phoswich detector for neutron spectrometry, which adopts a reversed configuration of slow- and fast-decay-time scintillators in its inner and surrounding outer regions, respectively, in the detection of recoil protons from a hydrogenous radiator. The phoswich detector consists of an inner slow, NaI(Tl) scintillator, and an outer fast, plastic scintillator. The response functions of the phoswich detector were measured for neutron energies ranging from 100 to 350 MeV. The experiment used the recoil-proton method and pulse-shape discrimination with the two-gate integration technique using a spallation neutron source at the WNR facility of the LANSCE. To evaluate the effectiveness of the phoswich configuration, full energy deposition fraction was calculated. The calculation confirmed that the phoswich detector with a reversed configuration is useful for neutron measurements.
-dependence of spin exchange interactions in MnO
( = Rare-Earth Ions)Kajimoto, Ryoichi; Mochizuki, Hidenori*; Yoshizawa, Hideki*; Shintani, Hiroshi*; Kimura, Tsuyoshi*; Tokura, Yoshinori*
Journal of the Physical Society of Japan, 74(9), p.2430 - 2433, 2005/09
Times Cited Count：37 Percentile：79.58(Physics, Multidisciplinary)Magnon excitations have been investigated for PrMnO showing the 
-type antiferromagnetic ordering and TbMnO forming a long-period spin ordering by inelastic neutron scattering. Combined with a result of LaMnO [K.~Hirota 
], the systematic data revealed that the ferromagnetic exchange interaction between nearest-neighbor (NN) Mn sites within the 
plane drastically decreases in MnO as the ionic radius of is reduced. In addition, finite next-nearest-neighbor (NNN) coupling is evident in TbMnO. In contrast, the exchange interaction along the 
axis shows much weaker dependence consistent with the Mn-O-Mn bond angle. These observations confirm a scenario that explains the evolution of spin structures in MnO in terms of the competition between the NN and NNN interactions [T.Kimura ].
Kajimoto, Ryoichi; Mitsui, Yukari*; Yoshizawa, Hideki*; Aso, Naofumi*; Shintani, Hiroshi*; Kimura, Tsuyoshi*; Tokura, Yoshinori*
no journal, ,
no abstracts in English
studied with spherical neutron polarimetryKajimoto, Ryoichi; Matsuda, Masaaki; Takeda, Masayasu; Kakurai, Kazuhisa; Mitsui, Yukari*; Yoshizawa, Hideki*; Kimura, Tsuyoshi*; Tokura, Yoshinori*
no journal, ,
no abstracts in English
studied by spherical polarimetryKajimoto, Ryoichi; Matsuda, Masaaki; Takeda, Masayasu; Kakurai, Kazuhisa; Mitsui, Yukari*; Yoshizawa, Hideki*; Kimura, Tsuyoshi*; Tokura, Yoshinori*
no journal, ,
no abstracts in English
Satoh, Daiki; Moriguchi, Daisuke*; Nakamura, Yasuhiro*; Kajimoto, Tsuyoshi*; Ueyama, Masahiko*; Yoshioka, Masakatsu*; Koba, Yusuke*; Shigyo, Nobuhiro*; Uozumi, Yusuke*; Matsufuji, Naruhiro*; et al.
no journal, ,
Neutron production double differential cross sections have been measured at HIMAC in National Institute of Radiological Sciences. The cross sections were obtained in the energy region from a few MeV to several hundred MeV. In addition, we got the systematic cross section data by revising the detection efficiencies in the existing data. All the data were compared with the predictions of Monte Carlo simulation codes. While the codes show a good agreement in the backward angular region, they can not reproduce the peak structure observed in the forward angular region. This indicates that the nucleus-nucleus reaction model in the simulation codes must be revised.
Satoh, Daiki; Shigyo, Nobuhiro*; Uozumi, Yusuke*; Moriguchi, Daisuke*; Kajimoto, Tsuyoshi*; Yoshioka, Masakatsu*; Ueyama, Masahiko*; Sanami, Toshiya*; Koba, Yusuke*; Matsufuji, Naruhiro*; et al.
no journal, ,
Neutron-production double-differential cross sections from heavy-ion interactions have been measured at Heavy-Ion Medical Accelerator in Chiba (HIMAC) of National Institute of Radiological Sciences (NIRS), Japan. 290-MeV/u O ions were bombarded upon a carbon target. The outgoing neutrons from the target were measured by a detection system that consist of two sizes of liquid organic scintillators with Time-of-Flight (TOF) technique in order to obtain a wide range of neutron spectrum from sub MeV to several hundred MeV. We have successfully measured the cross sections with a good precision.
Shigyo, Nobuhiro*; Uozumi, Yusuke*; Kajimoto, Tsuyoshi*; Moriguchi, Daisuke*; Ueyama, Masahiko*; Yoshioka, Masakatsu*; Koba, Yusuke*; Nakamura, Yasuhiro*; Satoh, Daiki; Sanami, Toshiya*; et al.
no journal, ,
Radiation dose by neutrons produced by proton and heavy ion induced nuclear reactions around tumor is essential for dose assessment in proton and heavy ion radiotherapies. Double differential cross section (DDX) of neutron production is one of important physical quantities for dose estimation by radiation transport codes. Some experimental data of neutron production DDXs have been reported above 5 MeV of neutron energy for heavy ion incident reactions. Neutron production DDX for carbon ion incidence on carbon target was measured at the Heavy Ion Medical Accelerator in Chiba (HIMAC) including low neutron energy region for validation of radiation transport codes. Incident carbon energy was 290 MeV/u. NE213 liquid organic scintillators were deployed as neutron detectors and placed at 15, 30 45, 60, 75 and 90. Neutron energies were determined by the time-of-flight methods. Neutron detection efficiency was calculated by the SCINFUL-QMD code. The obtained minimum neutron energy was about 2.8 MeV. The experimental data of neutron production DDX was compared with that by one of radiation transport codes, PHITS.
