Present status of the laser charge exchange test using the 3-MeV linac in J-PARC

Takei, Hayanori; Chishiro, Etsuji; Hirano, Koichiro; Kondo, Yasuhiro; Meigo, Shinichiro; Miura, Akihiko; Morishita, Takatoshi; Oguri, Hidetomo; Tsutsumi, Kazuyoshi

Proceedings of 5th International Beam Instrumentation Conference (IBIC 2016) (Internet), p.736 - 739, 2017/03

http://doi.org/10.18429/JACoW-IBIC2016-WEPG45

The Accelerator-driven System (ADS) is one of the candidates for transmuting long-lived nuclides, such as minor actinide (MA), produced by nuclear reactors. For efficient transmutation of the MA, a precise pre-diction of neutronics of ADS is required. In order to obtain the neutronics data for the ADS, the Japan Pro-ton Accelerator Research Complex (J-PARC) has a plan to build the Transmutation Physics Experimental Facility (TEF-P), in which a 400-MeV negative proton (H) beam will be delivered from the J-PARC linac. Since the TEF-P requires a stable proton beam with a power of less than 10W, a stable and meticulous beam extraction method is required to extract a small amount of the proton beam from the high power beam using 250kW. To fulfil this requirement, the Laser Charge Exchange (LCE) method has been developed. The LCE strips the electron of the H beam and neutral protons will separate at the bending magnet in the proton beam transport. To demonstrate the charge exchange of the H, a preliminary LCE experiment was conducted using a linac with energy of 3MeV in J-PARC. As a result of the experiment, a charge-exchanged H beam with a power of about 5W equivalent was obtained under the J-PARC linac beam condition, and this value almost satisfied the power requirement of the proton beam for the TEF-P.

Preliminary results of the laser charge exchange test using the 3-MeV linac in J-PARC

Takei, Hayanori; Hirano, Koichiro; Tsutsumi, Kazuyoshi; Chishiro, Etsuji; Miura, Akihiko; Kondo, Yasuhiro; Morishita, Takatoshi; Oguri, Hidetomo; Meigo, Shinichiro

Proceedings of 13th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.987 - 991, 2016/11

http://www.pasj.jp/web_publish/pasj2016/proceedings/PDF/TUP0/TUP052.pdf

Accelerator-driven system (ADS) is one of candidates to transmute long-lived nuclides such as minor actinide (MA) produced at nuclear reactor. For efficient transmutation of the MA, precise prediction of neutronics of ADS is indispensable. In order to obtain the neutronics data for the ADS, J-PARC has a plan to build the Transmutation Physics Experimental Facility (TEF-P). Since the TEF-P requires stable power of the beam and will operate with thermal power less than 500 W and the proton beam power of 10 W so that a stable and meticulous beam extraction method is required to extract small amount of the beam from the high power LINAC beam with 250 kW. To fulfill requirement, Laser charge exchange method (LCE) has been developed for delivery of 400-MeV proton beam with 25Hz to the TEF-P. The LCE strips the electron of H beam and H will separate at the bending magnet at the proton beam transport. The LCE device consists of YAG-laser with high power as 1.6 J/shot and 25 Hz and transport control system with high accuracy of the beam position. For the demonstration of the charge exchange of the H, the further LCE tests is conducted using H beam with energy of 3-MeV at RFQ test stand in J-PARC. In this paper, present status of LCE tests is presented.

Study on the Alteration of Hydrogeological and Mechanical Properties of the Cementitious Material (III); Summary Report

Takei, Akihiko*; Fujita, Hideki*; Harasawa, Shuichi*

JNC TJ8400 2004-025, 79 Pages, 2004/02

JNC-TJ8400-2004-025.pdf:5.79MB

We experimentally investigated the influence of several phenomena at the disposal environment, to evaluate the long-term alteration of cementitious material. The results are shown below. (1)Hardened cement paste specimens were altered and characterized after artificial seawater permeation. The calcium dissolution was accelerated, and secondary minerals containing magnesium were deposited. The permeability became one to three orders of magnitude smaller than data from specimens altered by deionized water permeation. It was estimated that secondary mineral formations reduced the permeability. These results meant that seawater and pure water differ remarkably from each other in influence to alteration of cementitious material. (2)Two type mixture proportions concrete, two type mixture proportions mortar and a cement paste under same W/C ratio 55% were characterized, to apply the accumulated data of paste to concrete or mortar. Compressive strength of paste was lower than that of concrete and mortar. It was contrary to the previous report. The behavior of Young's modulus and Poisson's ratio could be explained well using amount of aggregate. The data of permeability meant that boundary between aggregate and cement paste didn't become path of water flow, and that aggregate disturbed permeation. (3)Self-sealing property of cracked specimen of cementitious material were investigated by the water permeation test using sodium bicarbonate solution. The permeability decreased in two orders of magnitude, and possibility of sealing was suggested. By the morphology, the deposits in the cracks might be portlandite and C-S-H, and be not calcium carbonate. (4)Alteration of characteristics of cementitious material in sodium-nitrate and ammonia solution was evaluated by the water permeation test. Alteration degree of the nitrate and ammonia solution case showed similar trend to that of the sodium nitrate solution case. This result meant that ammonia solution would not ...

Study on the Alteration of Hydrogeological and Mechanical Properties of the Cementitious Material II

Takei, Akihiko*; Owada, Hitoshi*; Fujita, Hideki*; Negishi, Kumi*; Hibiya, Keisuke*; Yokozeki, Kosuke*; Watanabe, Kenzo*

JNC TJ8400 2003-047, 120 Pages, 2003/02

JNC-TJ8400-2003-047.pdf:4.46MB

We acquired the water permeation properties and also mechanical characteristics of the altered specimen that produced by permeation or immersing as the fundamental data.

The Effect of Nitrates on the Alteration of the Cementitious Material II

Takei, Akihiko*; Owada, Hitoshi*; Fujita, Hideki*; Negishi, Kumi*

JNC TJ8400 2003-042, 67 Pages, 2003/02

JNC-TJ8400-2003-042.pdf:4.7MB

TRU waste includes various chemical compounds such as nitrates. The influence of the chemical compounds on the performance of the barrier system should be estimated. In this study, we estimated the influence of sodium nitrate and also that of the chemical compounds derived from the sodium nitrate to the degradation of the cementitious material. 1) Evaluation of the influence of nitrate ion on the alteration of the cementitious material Alteration of characteristics of cementitious material was evaluated by the water permeation test using sodium nitrate solution. The calcium concentration of sodium nitrate solution permeated sample was higher than that of blank. The result indicates that sodium nitrate solution will accelerate the alteration of cementitious material. the permeation test was continued by using the ion-exchanged water as the permeation-water. As the results, the chemical and physical characteristics of the samples approached to those of blanks.2) Evaluation of the influence of ammonia on the alteration of the cementitious material Alteration of characteristics of cementitious material in nitrate and ammonia solution was evaluated by the water permeation test using 1mol/liter-sodium-nitrate and 0.5mol/liter-ammonia solution (denoted as NH-solution in the following). The calcium concentration of NH-solution permeated sample was higher than that of blank and the value of the calcium concentration was almost the same as that of the sodium nitrate solution case. The alteration range by the calcium leaching of the solid phase of the NH-solution case shows similar trend to that of the sodium nitrate solution case. The acceleration of the calcium dissolution was considered from this result. And the change of the water-permeability indicated the same trend with sodium-nitrate-solution case. From these results we confirmed that ammonia solution would not influence the alteration of cementitious solution.

Analysis of toroidal rotation effects of the ion polarization current on the neoclassical tearing mode

Takei, Nahoko; Ozeki, Takahisa; Smolyakov, A. I.*; Isayama, Akihiko; Hayashi, Nobuhiko; Iio, Shunji*; Shimada, Ryuichi*

Journal of Plasma and Fusion Research SERIES, Vol.5, p.386 - 389, 2002/00

no abstracts in English