Measurement of the longitudinal bunch-shape distribution for a high-intensity negative hydrogen ion beam in the low-energy region

Kitamura, Ryo; Futatsukawa, Kenta*; Hayashi, Naoki; Hirano, Koichiro; Kondo, Yasuhiro; Kosaka, Satoshi*; Miyao, Tomoaki*; Morishita, Takatoshi; Nemoto, Yasuo*; Oguri, Hidetomo

Physical Review Accelerators and Beams (Internet), 26(3), p.032802_1 - 032802_12, 2023/03

https://doi.org/10.1103/PhysRevAccelBeams.26.032802

A bunch-shape monitor (BSM) is a useful device for performing longitudinal beam tuning using the pointwise longitudinal phase distribution measured at selected points in the beam transportation. To measure the longitudinal phase distribution of a low-energy negative hydrogen (H) ion beam, highly oriented pyrolytic graphite (HOPG) was adopted for the secondary-electron-emission target to mitigate the thermal damage due to the high-intensity beam loading. The HOPG target enabled the measurement of the longitudinal phase distribution at the center of a 3-MeV H ion beam with a high peak current of about 50 mA. The longitudinal bunch width was measured using HOPG-BSM at the test stand, which was consistent with the beam simulation. The correlation measurement between the beam transverse and longitudinal planes was demonstrated using HOPG-BSM. The longitudinal Twiss and emittance measurement with the longitudinal Q-scan method was conducted using HOPG-BSM.

Bunch-size measurement of the high-intensity H beam with 3 MeV by the bunch-shape monitor

Kitamura, Ryo; Futatsukawa, Kenta*; Hayashi, Naoki; Hirano, Koichiro; Kondo, Yasuhiro; Kosaka, Satoshi*; Miyao, Tomoaki*; Nemoto, Yasuo*; Morishita, Takatoshi; Oguri, Hidetomo

JPS Conference Proceedings (Internet), 33, p.011012_1 - 011012_6, 2021/03

https://doi.org/10.7566/JPSCP.33.011012

The new bunch shape monitor (BSM) is required to measure the bunch size of the high-intensity H beam with 3 MeV at the front-end section in the J-PARC linac. The carbon-nano tube wire and the graphene stick are good candidates for the target wire of the BSM, because these materials have the enough strength to detect the high-intensity beam. However, since the negative high voltage of more than a few kV should be applied to the wire in the BSM, the suppression of the discharge is the challenge to realize the new BSM. After the high-voltage test to investigate the effect of the discharge from the wire, the detection of the signal from the BSM was successful at the beam core with the peak current of 55 mA using the graphene stick. The preliminary result of the bunch-size measurement is reported in this presentation.

Bunch shape monitor for the high-intensity H beam with 3 MeV using the carbon material

Kitamura, Ryo; Futatsukawa, Kenta*; Hayashi, Naoki; Hirano, Koichiro; Kosaka, Satoshi*; Miyao, Tomoaki*; Moriya, Katsuhiro; Nemoto, Yasuo*; Oguri, Hidetomo

Proceedings of 16th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.51 - 54, 2019/07

https://www.pasj.jp/web_publish/pasj2019/proceedings/index.html

The longitudinal measurement and tuning at the beam transport after the RFQ are important to reduce the beam loss and the emittance growth in the J-PARC linac, when the high-intensity H beam of more than 60 mA is supplied. The new bunch shape monitor (BSM) using the carbon-nanotube (CNT) wire is necessary to measure the bunch shape of the high-intensity H beam with 3 MeV, because the CNT wire has a high-temperature tolerance and a small energy deposit. However, when the high voltage was applied to the CNT wire to extract the secondary electron derived, the discharge prevents the power supply from applying the voltage. Therefore, the discharge should be suppressed to measure the bunch shape with stability. Considering the characteristics of the CNT as the emitter, when the length of the CNT wire was short, the high voltage of -10 kV was applied to the CNT wire. The current status and future prospects of the BSM using the CNT wire are reported in this presentation.

Retreat from stress; Rattling in a planar coordination

Suekuni, Koichiro*; Lee, C. H.*; Tanaka, Hiromi*; Nishibori, Eiji*; Nakamura, Atsushi*; Kasai, Hidetaka*; Mori, Hitoshi*; Usui, Hidetomo*; Ochi, Masayuki*; Hasegawa, Takumi*; et al.

Advanced Materials, 30(13), p.1706230_1 - 1706230_6, 2018/03

https://doi.org/10.1002/adma.201706230

Thermoelectric materials for highly efficient devices must satisfy conflicting requirements of high electrical conductivity and low thermal conductivity. In this paper, we studied the crystal structure and phonon dynamics of tetrahedrites (Cu,Zn)(Sb,As)S. The results revealed that the Cu atoms in a planar coordination are rattling, which effectively scatter phonons. These findings provide a new strategy for the development of highly efficient thermoelectric materials with planar coordination.

Uniaxial-pressure control of magnetic phase transitions in a frustrated magnet CuFeGaO ( = 0, 0.018)

Nakajima, Taro*; Mitsuda, Setsuo*; Takahashi, Keiichiro*; Yoshitomi, Keisuke*; Masuda, Kazuya*; Kaneko, Chikafumi*; Homma, Yuki*; Kobayashi, Satoru*; Kitazawa, Hideaki*; Kosaka, Masashi*; et al.

Journal of the Physical Society of Japan, 81(9), p.094710_1 - 094710_8, 2012/09

https://doi.org/10.1143/JPSJ.81.094710

Estimation of runoff volume by geomorphometry and statistics analysis using digital elevation model in Tono area

Takeuchi, Ryuji; Kosaka, Hiroshi; Sato, Atsuya*; Tomiyama, Shingo*; Kageyama, Soichiro*; Ikeda, Makoto*

JAEA-Research 2011-008, 77 Pages, 2011/06

JAEA-Research-2011-008.pdf:4.76MB

Subsurface water balance observation is a kind of methods in order to estimate a recharge rate. Results of the observation are affected by the various factors such as the scale, the topography, a geological feature, the climate. Therefore, the observation in the regional scale is necessary at many basins. The purpose of this study is to confirm the applicability of the method for the evaluation of runoff volume, which is one of parameters to evaluate the recharge rate by surface water balance observation, by geomorphometry and statistical analyses using digital elevation model (DEM). The runoff index which is the original indicator to evaluate the degree of flow rate on a catchment was calculated by the comparison between the result of geomorphometry and statistics analyses, and the observed data of river flow rate in the monitoring stations. Using this index, the flow rate of the Hiyoshi River was evaluated. The evaluated flow rate was about 60% against the observed flow rate.

Inventories of high burn up LWR UO spent fuel and ATR MOX spent fuel in Tokai Reprocessing Plant

Shirai, Nobutoshi; Inano, Masatoshi; Fukuda, Kazuhito; Kosaka, Ichiro; Yamanaka, Atsushi

JAEA-Research 2011-004, 60 Pages, 2011/03

JAEA-Research-2011-004.pdf:1.79MB

This report describes calculated results of inventory of radioactivity in the Tokai Reprocessing Plant with calculation code, based on initial conditions and nuclear data library. The inventories were compared with three types of spent fuels, High burn up U oxide for light water reactor, U-Pu mixed oxide for advanced thermal reactor and the design based fuel for Tokai Reprocessing Plant.

"Crystal lattice engineering", an approach to engineer protein crystal contacts by creating intermolecular symmetry; Crystallization and structure determination of a mutant human RNase 1 with a hydrophobic interface of leucines

Yamada, Hidenori*; Tamada, Taro; Kosaka, Megumi*; Miyata, Kohei*; Fujiki, Shinya*; Tano, Masaru*; Moriya, Masayuki*; Yamanishi, Mamoru*; Honjo, Eijiro; Tada, Horiko*; et al.

Protein Science, 16(7), p.1389 - 1397, 2007/07

https://doi.org/10.1110/ps.072851407

In an attempt to control protein incorporation in a crystal lattice, a leucine zipper-like hydrophobic interface (comprising four leucine residues) was introduced into a helical region (helix 2) of the human pancreatic ribonuclease 1 (RNase 1) that was predicted to form a suitable crystallization interface. Although crystallization of wild type RNase 1 has not yet been reported, the RNase 1 mutant having four leucines (4L-RNase 1) was successfully crystallized under several different conditions. The crystal structures were subsequently determined by X-ray crystallography by molecular replacement using the structure of bovine RNase A. The overall structure of 4L-RNase 1 is quite similar to that of the bovine RNase A, and the introduced leucine residues formed the designed crystal interface. To further characterize the role of the introduced leucine residues in crystallization of RNase 1, the number of leucines was reduced to three or two (3L- and 2L-RNase 1, respectively). Both mutants crystallized and a similar hydrophobic interface as in 4L-RNase 1 was observed. A related approach to engineer crystal contacts at helix 3 of RNase 1 (N4L-RNase 1) was also evaluated. N4L-RNase 1 also successfully crystallized, and formed the expected hydrophobic packing interface. These results suggest that appropriate introduction of a leucine zipper-like hydrophobic interface can promote intra molecular symmetry for more efficient protein crystallization in crystal lattice engineering efforts.

Evaluation of pressure transient of the facility by FIRAC code

Kosaka, Ichiro; Nojiri, Ichiro; Yamanouchi, Takamichi

JNC TN8410 99-017, 302 Pages, 1999/03

JNC-TN8410-99-017.pdf:13.87MB

For the purpuse of the analysis the loss of the containment of the gas, the pressure transients had been caluculated, using FIRAC Code, caused by the first fire incident in the Bitiminization filling cell, R152, and by the corst down of the cell exhaustion, limited operation of the ventilation system, begining at 1006, 11th, March, 1997. The FIRAC Code calculates the pressure and temperature of the cell and ventilation system at the fire incident. The all of the facility was modeled in the calculations. The heat generation rate and other unknown terms were taken into as the caluculational parameters, and the process of the incident were evaluated by attention to the different results by each parameter. In the results, the constraction of the ventilation system affected the process of the fire incident, and in the case taking account of exhausting to Z-facility, abnormal reverse flow occurred in the system.

Calculation of the reverse air flow rate to cells from the vessel ventilation system

Kosaka, Ichiro; Yamanouchi, Takamichi;

PNC TN8410 98-027, 114 Pages, 1998/02

PNC-TN8410-98-027.pdf:2.72MB

At 11th, March, 97, the fire incident happened, and after the fire incident, the explosion happened in the Bitiminization Demonstration Facility. It has been suspected that the reverse air flow to filling room(R152) from the vessel ventilation system made the explosive atmosphere after the fire incident. The calculation of the reverse flow rate to the cell was therfore carried out, using FIRAC computer code. The FIRAC is designed for the calculation of a fluid temperature, pressure and flow rate, using lumped-parameter method. In the FIRAC, the network system is modeled as nodes and branches. As the results of calculation, the reverse air flow rate to R152 from vessel ventilation system is about 94 m/h and the reverse air flow rate to the other cells are slight, assuming that the leak rate from R152 is 650 m/h and others are 1 vol%/h when the pressure difference is 40 mmAq. On the other hand, the reverse air flow rate to R152 is about 34m/h, the reverse air flow rate to the cells in the underground stairs is about 39 m/h and to the others are from 5 to 10 m/h, assuming that the leak rate from all cells are 1 vol%/h when the pressure difference is 40 mmAq.