http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Measurement of Unbound Excited States of ^(24)O
추경호,사토,T. Nakamura,N. Aoi,방형찬,S. CHOI,S. Deguchi,F. Delaunay,J. Gibelin,T. Honda,M. Ishihara,Y. Kawada,Y. Kondo,T. Kobayashi,N. Kobayashi,F. M. Marques,M. Matsushita,Y. Miyashita,T. Motobayashi,Y. Nak 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.23
The unbound excited states of the most neutron-rich oxygen isotope, ^(24)O (Z = 8, N = 16), have been investigated using the ^(24)O(p,p') ^(24)O^* → ^(23)O+n reaction at RIKEN, where a 63 MeV/neuclon secondary beam of ^(24)O was produced in a Be production target by the projectile-like fragmentation of a 95 MeV/u ^(40)Ar primary beam. The first excited 2^* state was observed in the invariant mass spectrum. This experiment will give us a deeper understanding of the new magic number at N=16 in the neutron-rich oxygen isotopes.
Invariant Mass Spectroscopy for the Neutron Rich Nuclei
사토,추경호,방형찬,S. H. Choi,T. Nakamura,Y. Kondo,Y. Nakayama,N. Kobayashi,K. N. Tanaka,S. Deguchi,Y. Kawada,N. Tanaka,T. Sugimoto,T. Motobayashi,H. Sakurai,H. Otsu,N. Aoi,Y. Yanagisawa,S. Takeuchi,N. Fukuda 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.23
The neutron-rich carbon isotopes ^(19,17)C and a boron isotope ^(14)B are investigated respectively via proton inelastic and charge-exchange reactions on a liquid hydrogen target at around 70 MeV/nucleon at RIKEN. The invariant mass method in inverse kinematics involving coincidence detection of a charged fragment and a neutron both emitted at forward angles is employed to map the energy spectrum above the neutron decay threshold. Several resonance structures are revealed in the invariant mass spectra, and the nature for some of them is discussed from comparisons of differential cross section data with predictions of microscopic DWBA calculations based on spsdpf shell model wave functions and a recent parametrization of semi-microscopic nucleon-nucleus optical model potential (JLMB). By extrapolating the (p,n) cross sections leading to the 1^+ state at 1.27 MeV in ^(141)B to zero momentum transfer the Gamow-Teller transition strength is deduced. The value is found to compare well with that reported in a β-delayed neutron emission study.
Tshoo, K.,Satou, Y.,Bertulani, C.A.,Bhang, H.,Choi, S.,Nakamura, T.,Kondo, Y.,Deguchi, S.,Kawada, Y.,Nakayama, Y.,Tanaka, K.N.,Tanaka, N.,Togano, Y.,Kobayashi, N.,Aoi, N.,Ishihara, M.,Motobayashi, T. Elsevier 2014 Physics letters: B Vol.739 No.-
<P><B>Abstract</B></P> <P>One-neutron knockout from <SUP>24</SUP>O leading to the first excited state in <SUP>23</SUP>O has been measured for a proton target at a beam energy of 62 MeV/nucleon. The decay energy spectrum of the neutron unbound state of <SUP>23</SUP>O was reconstructed from the measured four momenta of the <SUP>22</SUP>O fragment and emitted neutron. A sharp peak was found at <SUB> E decay </SUB> = 50 ± 3 keV , corresponding to an excited state in <SUP>23</SUP>O at 2.78 ± 0.11 MeV , as observed in previous measurements. The longitudinal momentum distribution for this state was consistent with <I>d</I>-wave neutron knockout, providing support for a <SUP> J π </SUP> assignment of 5 / <SUP> 2 + </SUP> . The associated spectroscopic factor was deduced to be <SUP> C 2 </SUP> S ( 0 <SUB> d 5 / 2 </SUB> ) = 4.1 ± 0.4 by comparing the measured cross section ( σ − 1 n exp = 61 ± 6 mb ) with a distorted wave impulse approximation calculation. Such a large occupancy for the neutron 0 <SUB> d 5 / 2 </SUB> orbital is in line with the N = 16 shell closure in <SUP>24</SUP>O.</P>
Kobayashi, T.,Ida, K.,Inagaki, S.,Tsuchiya, H.,Tamura, N.,Choe, G.H.,Yun, G.S.,Park, H.K.,Ko, W.H.,Evans, T.E.,Austin, M.E.,Shafer, M.W.,Ono, M.,Ló,pez-bruna, D.,Ochando, M.A.,Estrada, T.,Hidalg IOP 2017 Nuclear fusion. Fusion nucléaire. &n.Illiga Vol.57 No.7
<P>In this contribution we analyze modulation electron cyclotron resonance heating (MECH) experiment and discuss higher harmonic frequency dependence of transport coefficients. We use the bidirectional heat pulse propagation method, in which both inward propagating heat pulse and outward propagating heat pulse are analyzed at a radial range, in order to distinguish frequency dependence of transport coefficients due to hysteresis from that due to other reasons, such as radially dependent transport coefficients, a finite damping term, or boundary effects. The method is applied to MECH experiments performed in various helical and tokamak devices, i.e. Large Helical Device (LHD), TJ-II, Korea Superconducting Tokamak Advanced Research (KSTAR), and Doublet III-D (DIII-D) with different plasma conditions. The frequency dependence of transport coefficients are clearly observed, showing a possibility of existence of transport hysteresis in flux-gradient relation.</P>
Search for sub-GeV dark matter by annual modulation using XMASS-I detector
Kobayashi, M.,Abe, K.,Hiraide, K.,Ichimura, K.,Kishimoto, Y.,Kobayashi, K.,Moriyama, S.,Nakahata, M.,Ogawa, H.,Sato, K.,Sekiya, H.,Suzuki, T.,Takeda, A.,Tasaka, S.,Yamashita, M.,Yang, B.S.,Kim, N.Y.,K North-Holland Pub. Co 2019 Physics letters. Section B Vol.795 No.-
<P><B>Abstract</B></P> <P>A search for dark matter (DM) with mass in the sub-GeV region (0.32–1 GeV) was conducted by looking for an annual modulation signal in XMASS, a single-phase liquid xenon detector. Inelastic nuclear scattering accompanied by bremsstrahlung emission was used to search down to an electron equivalent energy of 1 keV. The data used had a live time of 2.8 years (3.5 years in calendar time), resulting in a total exposure of 2.38 ton-years. No significant modulation signal was observed and 90% confidence level upper limits of 1.6 × <SUP> 10 − 33 </SUP> cm<SUP>2</SUP> at 0.5 GeV was set for the DM-nucleon cross section. This is the first experimental result of a search for DM mediated by the bremsstrahlung effect. In addition, a search for DM with mass in the multi-GeV region (4–20 GeV) was conducted with a lower energy threshold than previous analysis of XMASS. Elastic nuclear scattering was used to search down to a nuclear recoil equivalent energy of 2.3 keV, and upper limits of 2.9 × <SUP> 10 − 42 </SUP> cm<SUP>2</SUP> at 8 GeV was obtained.</P>
Yamashita, N.,Gasnault, O.,Forni, O.,d'Uston, C.,Reedy, R.C.,Karouji, Y.,Kobayashi, S.,Hareyama, M.,Nagaoka, H.,Hasebe, N.,Kim, K.J. Elsevier 2012 Earth and planetary science letters Vol.353 No.-
<P><B>Abstract</B></P> <P>The first unambiguous global distribution of Ca on the Moon has been revealed by the Kaguya Gamma-Ray Spectrometer. The observation of the 3737keV gamma rays from <SUP>40</SUP>Ca with a high energy resolution Ge detector, corrected for fast neutrons, improved greatly our confidence in these remote sensing data. While the derived Ca abundance generally confirms the mare-highland dichotomy, we found that the eastern mare regions such as Crisium, Nectaris, and Fecunditatis exhibit unexpected high Ca abundances. This may be explained by regional concentrations of high-Ca clinopyroxene. Our Ca map also shows that the lowest CaO abundance found in the returned samples (∼8wt%) may actually be common in Oceanus Procellarum, suggesting the possible sampling bias of Apollo and Luna missions. These observational results on Ca serve as a complementary criterion for better characterization of mare regions on the Moon.</P> <P><B>Highlights:</B></P> <P>► Global distribution of Ca on the Moon is derived from Kaguya GRS data. ► Observation by high precision Ge detector greatly improved confidence in measurement. ► Ca was found to be more abundant in the east mare region than in the west. ► Selective concentration of high-Ca pyroxene in the eastern mare region is implied. ► Ca provides a complementary criterion to characterize the lunar thermal history.</P>