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= 8
two-quasineutron isomer in 
PuHota, S.*; Tandel, S.*; Chowdhury, P.*; Ahmad, I.*; Carpenter, M. P.*; Chiara, C. J.*; Greene, J. P.*; Hoffman, C. R.*; Jackson, E. G.*; Janssens, R. V. F.*; et al.
Physical Review C, 94(2), p.021303_1 - 021303_5, 2016/08
Times Cited Count：6 Percentile：44.35(Physics, Nuclear)The decay of a = 8 isomer in Pu and the collective band structure populating the isomer are studied using deep inelastic excitations with 
Ti and 
Pb beams, respectively. Precise measurements of 
branching ratios in the band confirm a clean 9/2
[734]
7/2
[624] for the isomer, validating the systematics of K
= 8 two-quasineutron isomers observed in even-
, 
= 150 isotones. These isomers around the deformed shell gap at = 152 provide critical benchmarks for theoretical predictions of single-particle energies in this gateway region to superheavy nuclei.
Kawano, Yasunori; Akiyama, Tsuyoshi*; Ishikawa, Masao; Isobe, Mitsutaka*; Itami, Kiyoshi; Ejiri, Akira*; Peterson, B.*
Purazuma, Kaku Yugo Gakkai-Shi, 92(2), P. 145, 2016/02
no abstracts in English
Kawano, Yasunori; Akiyama, Tsuyoshi*; Ishikawa, Masao; Isobe, Mitsutaka*; Itami, Kiyoshi; Ejiri, Akira*; Peterson, B.*
Purazuma, Kaku Yugo Gakkai-Shi, 91(8), P. 565, 2015/08
no abstracts in English
Kawano, Yasunori; Akiyama, Tsuyoshi*; Ishikawa, Masao; Isobe, Mitsutaka*; Itami, Kiyoshi; Ejiri, Akira*; Peterson, B. J.*
Purazuma, Kaku Yugo Gakkai-Shi, 91(1), P. 76, 2015/01
no abstracts in English
Kawano, Yasunori; Akiyama, Tsuyoshi*; Ishikawa, Masao; Isobe, Mitsutaka*; Itami, Kiyoshi; Ejiri, Akira*; Peterson, B.*
Purazuma, Kaku Yugo Gakkai-Shi, 90(7), P. 431, 2014/07
no abstracts in English
Kawano, Yasunori; Itami, Kiyoshi; Kawahata, Kazuo*; Kusama, Yoshinori; Sasao, Mamiko*; Peterson, B.*; Mase, Atsushi*
Purazuma, Kaku Yugo Gakkai-Shi, 90(2), P. 164, 2014/02
no abstracts in English
Itami, Kiyoshi; Kawano, Yasunori; Kawahata, Kazuo*; Kusama, Yoshinori; Sasao, Mamiko*; Peterson, B.*; Mase, Atsushi*
Purazuma, Kaku Yugo Gakkai-Shi, 89(9), P. 638, 2013/09
no abstracts in English
Asakura, Nobuyuki; Ashikawa, Naoko*; Ueda, Yoshio*; Ono, Noriyasu*; Tanabe, Tetsuo*; Nakano, Tomohide; Masuzaki, Suguru*; Itami, Kiyoshi; Kawano, Yasunori; Kawahata, Kazuo*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 87(7), p.485 - 486, 2011/07
no abstracts in English
isomer in 
RfRobinson, A. P.*; Khoo, T. L.*; Seweryniak, D.*; Ahmad, I.*; Asai, Masato; Back, B. B.*; Carpenter, M. P.*; Chowdhury, P.*; Davids, C. N.*; Greene, J.*; et al.
Physical Review C, 83(6), p.064311_1 - 064311_7, 2011/06
Times Cited Count：32 Percentile：84.78(Physics, Nuclear)We have identified an isomer with a half-life of 17 
s in Rf through a calorimetric conversion electron measurement tagged with implanted Rf nuclei using the fragment mass analyzer at Argonne National Laboratory. The low population yield for this isomer suggests that this isomer should not be a 2-quasiparticle high- isomer which is typically observed in the N = 152 isotones, but should be a 4-quasiparticle one. Possible reasons of the non-observation of a 2-quasiparticle isomer are this isomer decays by fission with a half-life similar to that of the ground state of Rf. Another possibility, that there is no 2-quasiparticle isomer at all, would imply an abrupt termination of axially symmetric deformed shape at Z=104.
Kawano, Yasunori; Sasao, Mamiko*; Mase, Atsushi*; Kawahata, Kazuo*; Kusama, Yoshinori; Peterson, B.*; Itami, Kiyoshi
Purazuma, Kaku Yugo Gakkai-Shi, 86(9), P. 552, 2010/09
no abstracts in English
Seweryniak, D.*; Khoo, T. L.*; Ahmad, I.*; Kondev, F. G.*; Robinson, A.*; Tandel, S. K.*; Asai, Masato; Back, B. B.*; Carpenter, M. P.*; Chowdhury, P.*; et al.
Nuclear Physics A, 834(1-4), p.357c - 361c, 2010/03
Times Cited Count：7 Percentile：47.69(Physics, Nuclear)Experimental data on single-particle energies in nuclei around Z=100 and N=152 play an important role to test validity of theoretical predictions for shell structure of superheavy nuclei. We found high-K two-quasiparticle isomers in 
No and 
No, and evaluated energies of proton single-particle orbitals around Z=100. We also found a new high-K three quasiparticle isomer in 
Rf. Energies of neutron single-particle orbitals were also evaluated from experimental data of the 
decay of Rf. Comparisons between the present experimental data and various theoretical calculations for the proton single-particle orbitals indicate that the calculation by using the Woods-Saxon potential gives the best agreement with the data.
RfQian, J.*; Heinz, A.*; Khoo, T. L.*; Janssens, R. V. F.*; Peterson, D.*; Seweryniak, D.*; Ahmad, I.*; Asai, Masato; Back, B. B.*; Carpenter, M. P.*; et al.
Physical Review C, 79(6), p.064319_1 - 064319_13, 2009/06
Times Cited Count：31 Percentile：83.86(Physics, Nuclear)-, 
-, and conversion electron spectroscopy experiments for Rf have been performed using Fragment Mass Analyzer at Argonne National Laboratory. A new isomer with a half-life of 160 s has been discovered in Rf, and it is interpreted as a three-quasiparticle high- isomer. Neutron configurations of one-quasiparticle states in 
No, the -decay daughter of Rf, have been assigned on the basis of -decay hindrance factors. Excitation energies of the 1/2
[620] states in =151 isotones indicate that the deformed shell gap at =152 increases with the atomic number.
Kawano, Yasunori; Sasao, Mamiko*; Mase, Atsushi*; Kawahata, Kazuo*; Kusama, Yoshinori; Peterson, B.*; Itami, Kiyoshi
Purazuma, Kaku Yugo Gakkai-Shi, 85(5), P. 314, 2009/05
The 15th meeting of international tokamak physics activity (ITPA) topical group on diagnostics was held in Ahmadabad, India, 17-20 November 2008. Fifty-three scientists participated the meeting (JA:2, IN:24, EU:17, US:3, RF:3, ITER Organization (IO):4). In 2008, ITPA was restructured to be the activity under the "auspice of ITER". Accordingly, the chair and the co-chair persons were newly appointed. Since it was the first meeting after the restructuring, new guidelines of activities in this topical group were discussed together with the progress of high priority items defined by this group and status of development of ITER diagnostics in ITER participant parties and IO. In this report, the outline of the meeting is presented.
isomers and 
octupole vibrations in 
shell-stabilized isotonesRobinson, A. P.*; Khoo, T. L.*; Ahmad, I.*; Tandel, S. K.*; Kondev, F. G.*; Nakatsukasa, Takashi*; Seweryniak, D.*; Asai, Masato; Back, B. B.*; Carpenter, M. P.*; et al.
Physical Review C, 78(3), p.034308_1 - 034308_6, 2008/09
Times Cited Count：49 Percentile：90.79(Physics, Nuclear)Isomers have been identified in 
Cm and No with quantum number , which decay through rotational bands built on octupole vibrational states. For isotones with atomic number 
102, the and 2 states have remarkably stable energies, indicating neutron excitations. An exception is a singular minimum in the 2 energy at Cm, due to the additional role of proton configurations.
Peterson, B. J.*; Konoshima, Shigeru; Kostryukov, A. Y.*; Seo, D. C.*; Liu, Y.*; Miroshnikov, I. V.*; Ashikawa, Naoko*; Parchamy, H.*; Kawashima, Hisato; Iwama, Naofumi*; et al.
Plasma and Fusion Research (Internet), 2, p.S1018_1 - S1018_4, 2007/11
An overview of the research and development of imaging bolometers giving a perspective on the applicability of this diagnostic to a fusion reactor is presented. Traditionally the total power lost from a high temperature has been measured using one dimensional arrays of resistive bolometers. The large number of signal wires associated with these resistive bolometers poses hazards not only at the vacuum interface, but also in the loss of electrical contacts that has been observed in the presence of fusion reactor levels of neutron flux. Infrared imaging video bolometers (IRVB), on the other hand, use the infrared radiation from the absorbing metal foil to transfer the signal through the vacuum interface and out from behind a neutron shield. The IRVB can provide hundreds of channels of bolometric signal in an image of the plasma radiation. Recently a prototype IRVB has been deployed on the JT-60U tokamak which demonstrates the ability of this diagnostic to operate in a reactor environment.
Liu, Y.*; Tamura, Naoki*; Peterson, B. J.*; Iwama, Naofumi*; Konoshima, Shigeru; LHD Experimental Group*; JT-60 Team
Plasma and Fusion Research (Internet), 2, p.S1124_1 - S1124_4, 2007/11
Two improved tomographic algorithms, including a linear (Tikhonov-Phillips) and a nonlinear (maximum entropy) regularisation method, have been employed for multi-pixel bolometric measurements in order to get as much information as possible while keeping the assumptions to a minimum. The most important features of these improved methods are the capability of reconstructing radiation distributions without any symmetry assumptions, built-in smoothing, and useful reconstructions with relatively few detectors. Furthermore, the effects of finite detector size have been taken into account with a full three dimensional treatment of the detector geometry. The application of tomographic imaging was implemented to a two-array X-ray camera on the Large Helical Device (LHD) and a two-dimensional infrared imaging bolometric pinhole camera on JT-60U. Pertinent examples of the results are presented both to illustrate the analysis techniques and to demonstrate the wealth of physics which can be studied.
Araghy, H. P.*; Peterson, B. J.*; Hayashi, Hiromi*; Konoshima, Shigeru; Ashikawa, Naoko*; Seo, D. C.*; JT-60U Team
Plasma and Fusion Research (Internet), 2, p.S1116_1 - S1116_4, 2007/11
We obtain the local foil properties of the JT-60U imaging bolometer foil (a single graphite-coated gold foil with an effective area of 9 
7 cm
and a nominal thickness of 2.5 microns) such as the thermal diffusivity and the product of the thermal conductivity and the thickness of the foil by the foil calibration. Calibration of the foil was made in situ using a He-Ne laser (27 mW) as a known radiation source to heat the foil. The thermal images of the foil are provided by an IR camera (micro-bolometer type). The parameters are determined by finite element modeling of the foil temperature and comparing the solution to the experimental results. In this work we apply this calibration technique to investigate the spatial variation of the foil parameters. Significant variation in the local temperature rise of the foil due to local heating by the laser beam indicates a spatial variation of the foil parameters. This variation is possibly due to nonuniformity in the carbon coating and/or the thickness of the foil. In a separate work, the spatial calibration data will be used to produce the bolometer intensity data to be utilized in the tomographic analyses.
Peterson, B. J.*; Konoshima, Shigeru; Parchamy, H.*; Kaneko, Masashi*; Omori, Toshimichi*; Seo, D. C.*; Ashikawa, Naoko*; Sukegawa, Atsuhiko; JT-60 Team
Journal of Nuclear Materials, 363-365, p.412 - 415, 2007/06
Times Cited Count：13 Percentile：66.07(Materials Science, Multidisciplinary)Diagnosis of the radiation from both the divertor and core plasma regions is a key issue for the study of impurities resulting from plasma-surface interaction in existing magnetic plasma confinement experiments and future fusion reactors. An infrared imaging video bolometer has been designed, fabricated and installed on the JT-60U tokamak. This diagnostic utilizes an IR camera to image the temperature change of a thin foil which is exposed to plasma radiation through an aperture resulting in an image of the incident plasma radiation absorbed by the foil. In the 2004-2005 experimental campaign intitial data was taken which was limited to 8-bit analog video data from ohmic and hydrogen neutral beam discharges due to inadequate shielding. The semitangential, wide-angle view of the plasma covers the entire poloidal cross-section and the divertor extending over 90 degrees toroidally. This preliminary data showed a strong radiation zone from the divertor that moved up into the core plasma as the discharge terminated in agreement with the data from the resistive bolometer arrays. For the current campaign we have upgraded the system by improving the shielding against neutrons, and magnetic field. This has enabled operation of the camera during high magnetic field and some high power deuterium neutral beam discharges. We also improved the triggering and data transmission system to acquire 14-bit digital data. This will allow processing of the IR camera data to produce images of the radiation brightness at the foil which can be viewed as a movie with a frame rate of 30 fps. This data is used to study the toroidal uniformity of the radiation from the divertor in JT-60U.
Donn
, A. J. H.*; Costley, A. E.*; Barnsley, R.*; Bindslev, H.*; Boivin, R.*; Conway, G.*; Fisher, R.*; Giannella, R.*; Hartfuss, H.*; von Hellermann, M. G.*; et al.
Nuclear Fusion, 47(6), p.S337 - S384, 2007/06
Times Cited Count：335 Percentile：78.95(Physics, Fluids & Plasmas)no abstracts in English
Sasao, Mamiko*; Yamada, Hiroshi*; Baba, Mamoru*; Kondoh, Takashi; Peterson, B. J.*; Kawahata, Kazuo*; Mase, Atsushi*; Yoshikawa, Masayuki*; Azechi, Hiroshi*; Toi, Kazuo*; et al.
Fusion Science and Technology, 51(2T), p.40 - 45, 2007/02
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)Several unexplored physics issues will be studied in burning plasma experiments, planned on ITER in the near future. To carry out these studies, it is essential to develop novel diagnostic systems, such as fusion product measurement systems and high-resolution, high-reliability profile measurement of various plasma parameters. Scientific research on "Advanced Diagnostics for Burning Plasma Experiment" was assigned as a priority area by MEXT in 2004, and more than 20 studies are currently underway under this program. The feasibility of several new diagnostic concepts applicable to ITER is examined and diagnostic components for these systems are now under development.
