Investigation of the electronic structure of the MgZnY alloy using X-ray photoelectron spectroscopy

Miyazaki, Hidetoshi*; Akatsuka, Tatsuyoshi*; Kimura, Koji*; Egusa, Daisuke*; Sato, Yohei*; Itakura, Mitsuhiro; Takagi, Yasumasa*; Yasui, Akira*; Ozawa, Kenichi*; Mase, Kazuhiko*; et al.

Materials Transactions, 64(6), p.1194 - 1198, 2023/06

https://doi.org/10.2320/matertrans.MT-MD2022019

We investigated the electronic structure of the MgZnY alloy using hard and soft X-ray photoemission spectroscopy and electronic band structure calculations to understand the mechanism of the phase stability of this material. Electronic structure of the MgZnY alloy showed a semi-metallic electronic structure with a pseudo-gap at the Fermi level. The observed electronic structure of the MgZnY alloy suggests that the presence of a pseudogap structure is responsible for phase stability.

Quasifree neutron knockout reaction reveals a small -Orbital component in the Borromean nucleus B

Yang, Z. H.*; Kubota, Yuki*; Corsi, A.*; Yoshida, Kazuki; Sun, X.-X.*; Li, J. G.*; Kimura, Masaaki*; Michel, N.*; Ogata, Kazuyuki*; Yuan, C. X.*; et al.

Physical Review Letters, 126(8), p.082501_1 - 082501_8, 2021/02

AA2020-0819.pdf:1.29MB

https://doi.org/10.1103/PhysRevLett.126.082501

A quasifree (,) experiment was performed to study the structure of the Borromean nucleus B, which had long been considered to have a neutron halo. By analyzing the momentum distributions and exclusive cross sections, we obtained the spectroscopic factors for and orbitals, and a surprisingly small percentage of 9(2)% was determined for . Our finding of such a small component and the halo features reported in prior experiments can be explained by the deformed relativistic Hartree-Bogoliubov theory in continuum, revealing a definite but not dominant neutron halo in B. The present work gives the smallest - or -orbital component among known nuclei exhibiting halo features and implies that the dominant occupation of or orbitals is not a prerequisite for the occurrence of a neutron halo.

Nuclear structure of Ni from the (,) reaction

Elekes, Z.*; Kripk, *; Sohler, D.*; Sieja, K.*; Ogata, Kazuyuki*; Yoshida, Kazuki; Doornenbal, P.*; Obertelli, A.*; Authelet, G.*; Baba, Hidetada*; et al.

Physical Review C, 99(1), p.014312_1 - 014312_7, 2019/01

https://doi.org/10.1103/PhysRevC.99.014312

The nuclear structure of the Ni nucleus was investigated by (,) reaction using a NaI(Tl) array to detect the deexciting prompt rays. A new transition with an energy of 2227 keV was identified by and coincidences. Our shell-model calculations using the Lenzi, Nowacki, Poves, and Sieja interaction produced good candidates for the experimental proton hole states in the observed energy region, and the theoretical cross sections showed good agreement with the experimental values. Although we could not assign all the experimental states to the theoretical ones unambiguously, the results are consistent with a reasonably large Z = 28 shell gap for nickel isotopes in accordance with previous studies.

The rationalization design of large equipment dismantling facility (LEDF); Demonstration test on extinguishing of the cell (II)

; ; Matsumoto, Yoshihiro; ; Kato, Noriyoshi; Miyazaki, Hitoshi; Tanimoto, Kenichi

JNC TN9410 2002-010, 62 Pages, 2002/11

JNC-TN9410-2002-010.pdf:2.37MB

The vaporizer in extinguishing of Large Equipment Dismantling Facility (LEDF)that cost is considering as a plan to cut down as part of a rationalization design highly. When the vaporizer is deleted, it becomes here where liquefied carbon dioxide is emitted in the direct cell, it is necessary to grasp the action and extinguishing performance of the pressure change in the cell by rapid evaporation test of the emitted liquefied carbon dioxide. So pressure action inside the fire laboratory in liquefied carbon dioxide release and a putting out the fire tests due to the combustion time of the combustible were enforced by using the general fire laboratory with Demonstration Test on Extinguishing of the cell (I) in the llth year of Heisei. However, since these tests are after laboratory without airtightness, it needs to grasp the pressure action at the time of liquefied carbon dioxide discharge under the airtight high conditions of having assumed the still more nearly actual cell. The cell (II) Demonstration Test on Extinguishing using the vessel of Sodium Leak Fire and Aerosol test rig (SOLFA-2) container inside of OEC was carried out. The results were as follows. (1)In order to grasp the pressure action of the vessel, the internal pressure of SOLFA-2 was set as -50mmHO, and emitted liquefied carbon dioxide. Consequently, the tendency for the pressure in the vessel to descend rapidly immediately after liquefied carbon dioxide discharge, and to descend gently-sloping through the process which goes up gradually after that and goes abruptly up for a short time was seen. (2)The process which goes abruptly up in an above-mentioned short time is considered to be the factors with main what some liquefied carbon dioxide emitted in the vessel changed to dry ice, and was deposited taken and sublimating surrounding heat, and evaporating again. (3)It sets to total flooding system and the average minimum temperature in the vessel becomes about -48C, and at ...

The design of the hazardous substance sorting system applicability check of X-ray fluorescence spectrometer

; ; ; Kato, Noriyoshi; Miyazaki, Hitoshi; Tanimoto, Kenichi

JNC TN9410 2002-006, 49 Pages, 2002/07

JNC-TN9410-2002-006.pdf:1.84MB

Construction of LEDF (Large Equipment Dismantling Facility) is being planned by Waste Management Section. This purpose of LEDF is the melting treatment of the radioactive waste in OEC (O-arai Engineering Center) and the waste package in JAERI (O-arai Japan Atomic Energy Research Institute). It is also considered about the disposal plan of the future. Therefore LEDF has the sorting process of waste because of the removal of problematic substances. But that process is conducted using its human eyes. This process needs automatic operation because of high classification accuracy, high reliability, burden reduction of a worker. Then we select EXFS (Energy dispersive X-ray Fluorescence Spectrometer), and conducted the measurement of waste (a sample) with this device. That purpose is to confirm an application as the sorting device. A confirmation result is shown in the following. (1)Sorting performance Measurement is possible without pretreatment, if it is metal. However, sorting is difficult when paint, plating, impurities, etc. are shown in the surface. (2)Measurement position It is necessary to set a gap of the measurement thing from a measurement position to 4㎜ or less. (3)Radiation influence Because the background had risen by the influence of a radiant ray, the distinction of Fluorescence X-ray became difficult. Therefore the distinction of materials became impossible. Aluminum is influenced specially by it. As a conclusion, the application nature of EXFS thing Sorting System is high. But there is a bad influence by radiation. Therefore, difficult is installation into the cell. In order to apply EXFS to LEDF, it is necessary to place it outside the cell and to use as the help of the visual inspection.

The canister durability tests of the in-can type incineration-melting furnace

; Kato, Noriyoshi; Miyazaki, Hitoshi; Tanimoto, Kenichi

JNC TN9410 2001-018, 114 Pages, 2001/09

JNC-TN9410-2001-018.pdf:12.35MB

Construction of LEDF (Large equipment dismantling facility) which has the in-can type incineration-melting furnace is planned. The in-can type incineration-melting furnace performs incineration and melting solidification of radioactive waste within the canister made from ceramics, and is characterized by discarding the canister. On the other hand, as for this furnace, the amount of incineration is restrained to canister capacity, Therefore, how to repeat incineration and melting can be considered as a method of increasing the amount of incineration. However, we were anxious about the contact time of the melt and a canister extending, the amount of wear of canister base material increasing, or the heat load (heat cycle) to a canister increasing, and the material intensity of canister base material falling, in order that this method may repeat incineration and melting. then, the tests used imitation waste, are the conditions which repeat (1,3, 10 bathes) the incineration temperature of 1000 C, and the melt temperature of 1500 C, and investigated change of the amount of wear of canister base material and high temperature bend strength. The result is as follows. (1) The amount of wear of canister base material was 0.09 mm/h at the maximum. This result was a sufficiently few value, even if compared with the conventional result (1.0 mm/h). Moreover, the high temperature bend strength of canister base material is about 3 Mpa on an average, and change was seen before and after the examination to which heat load is applied. (2) These tests showed that the factor which spoils the soundness of a canister was oxidization degradation of the canister base material by peeling from the base material of Glaze (glass coating material). The portion embrittlement by oxidization degradation is locally worn down by contact of the melt. (3)Heat-resistant temperature of Glaze is about 1300 C. At the melting operation temperature of 1500 C, and ...

Tests on decisive proof for the incinerating and melting facility using the in-can type high frequency induction heating

; ; Kato, Noriyoshi; Miyazaki, Hitoshi; Tanimoto, Kenichi

JNC TN9410 2000-002, 149 Pages, 1999/12

JNC-TN9410-2000-002.pdf:23.51MB

LEDF (Large Equipment Dismantling Facility) is the solid waste processing technology development facility that carries out high-volume reduction and low dosage processing. The high-volume reduction processing of the high dose -waste configured with combustible waste, pvc & rubber, spent ion exchange resin, and noncombustible waste have been planned the incinerating and melting facility using the in-can type high frequency induction heating in LEDF. This test is intended to clarify the design data. It was confirmed that the incinerating and melting performance, molten solid properties and exhaust gas processing performance with pilot testing equipment and bench scale equipment. The result of this test are as follows. (1)Processing speed is 6.7kg/h for the combustible waste, 13.0kg/h for the ion exchange resin, and 30.0kg/h for the noncombustible waste. For above optimum processing conditions are as follows. (a)Operating temperature is 1000C for the combustible waste, 1300C for the ion exchange resin, 1500C for the noncombustible waste. (b)Air flow is 90Nm/h. Air temperature is 300C. Air velocity is 20m/s. (2)Incineration time per day is 5h. Warm-up time and incineration time from the stop of waste charging is 0.5h. Melting time per day is 5h inconsideration of heating hold time of incinerated ash and melting of quartz. Warm-up time is 0.5h. (3)The system decontamination factor in Co, Cs and Ce with pilot testing equipment is 10 or more. (4)Design data of the iron doped silica gel judged to be have a applicability as RuO gas absorber is as follows. (a)Its diameter distribute in the range of 0.8-1.7mm. (b)To have a decontamination factor of 10 can achieve for retention time of 3 seconds and its life time is about 1 year. (5)In terms of the distribution of the nuclear species in molten solid is evenly distributed. It was also confirmed that the distribution of main elements in ceramic layer is ...

None

; Miyazaki, Hitoshi; ; Tanimoto, Kenichi; Terunuma, Seiichi

PNC TN9420 94-010, 103 Pages, 1994/04

PNC-TN9420-94-010.pdf:2.89MB

None

On the turn determination of crush zone activity; A Lesson from granitic basement rock holding the fast breeder reactor "Monju"

Shimada, Koji; Tateishi, Ryo*; Ishimaru, Tsuneari; Sasaki, Akimichi; Tanaka, Yukumo; Miyazaki, Masashi; Yasue, Kenichi; Niwa, Masakazu; Sueoka, Shigeru; Umeda, Koji; et al.

no journal, , 

Activity evaluation of crush zones encountered in basement rock is an issue of the seismic safety assessment of nuclear plant and geological isolation of radioactive wastes. The selection of crush zone of which has been evaluated should be defined as the latest one by means of turn determination of crush zone activity based on stratigraphic or structural geological method. A lesson from granitic basement rock (Kojaku granite) holding the fast breeder reactor "Monju" is presented. The Kojaku Granite form the oval Tsuruga peninsula (ca. 8km in width) on the southeastern coast of the Sea of Japan and the age is 68.5 plus/minus 0.7Ma (Zircon U-Pb age).1. Stratigraphy-oriented turn determination of crush zone activity. (1.1) Turn determination using cover sediments. (1.2) Turn determination using dyke, mineral and clay vein. 2. Structural-oriented turn determination of crush zone activity.