WordNet
- the rate of flow of neutrons; the number of neutrons passing through a unit area in unit time
- a state of uncertainty about what should be done (usually following some important event) preceding the establishment of a new direction of action; "the flux following the death of the emperor" (同)state of flux
- a substance added to molten metals to bond with impurities that can then be readily removed
- excessive discharge of liquid from a cavity or organ (as in watery diarrhea)
- the rate of flow of energy or particles across a given surface
- in constant change; "his opinions are in flux"; "the newness and flux of the computer industry"
- a flow or discharge (同)fluxion
- an elementary particle with 0 charge and mass about equal to a proton; enters into the structure of the atomic nucleus
PrepTutorEJDIC
- 流動,流れ;上げ潮 / 絶え間ない変化,流転(るてん) / 融剤,フラックス / (流体・粒子・エネルギーの)流量,流束,流動率 / (電気・磁気の)束(そく) / (体内の液体の)異常流出,異常排出
- 中性子,ニュートロン(原子核の構成要素の一つ)
- インフルエンザ,流感
Wikipedia preview
出典(authority):フリー百科事典『ウィキペディア(Wikipedia)』「2014/04/22 15:26:42」(JST)
[Wiki en表示]
|
This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (July 2008) |
The neutron flux is a quantity used in nuclear reactor physics corresponding to the total length travelled by all neutrons per unit time and volume,[1] or nearly equivalently number of neutrons travelling through unit area in unit time.[2] The neutron fluence is defined as the neutron flux integrated over a certain time period.
Contents
- 1 Natural neutron flux
- 2 Artificial neutron flux
- 3 References
- 4 See also
Natural neutron flux
Neutron flux in asymptotic giant branch stars and in supernova is responsible for most of the natural nucleosynthesis producing elements heavier than iron. In stars there is a relatively low neutron flux on the order of 105 to 1011 neutrons per cm2 per second, resulting in nucleosynthesis by the s-process (slow-neutron-capture-process). By contrast, after a core-collapse supernova, there is an extremely high neutron flux, on the order of 1022 neutrons per cm² per second, resulting in nucleosynthesis by the r-process (rapid-neutron-capture-process).
Atmospheric neutron flux, apparently from thunderstorms, can increase to 3-5•10-2 neutrons cm-2 sec-1.[3]
Artificial neutron flux
Further information: Neutron radiation
Artificial neutron flux refers to neutron flux which is man-made, either as byproducts from weapons or nuclear energy production or for specific application such as from a research reactor or by spallation. A flow of neutrons is often used to initiate the fission of unstable large nuclei. The additional neutron(s) may cause the nucleus to become unstable, causing it to decay (split) to form more stable products. This effect is essential in fission reactors and nuclear weapons.
Within a nuclear fission reactor the neutron flux is primarily the form of measurement used to control the reaction inside. The flux shape is the term applied to the density or relative strength of the flux as it moves around the reactor. Typically the strongest neutron flux occurs in the middle of the reactor core, becoming lower toward the edges. The higher the neutron flux the greater the chance of a nuclear reaction occurring as there are more neutrons going through an area.
A reactor vessel of a typical nuclear power plant (PWR) endures in 40 years (32 full reactor years) of operation approximately 3,5*1019 n/cm² (E>1MeV).[4] Neutron flux causes reactor vessels to suffer from embrittlement and the steel gets activated.
References
- ^ Rudi J. J. Stamm'ler, Máximo Julio Abbate, Methods of steady-state reactor physics in nuclear design
- ^ Neutron flux from the United States Nuclear Regulatory Commission, retrieved 30 May 2008
- ^ Gurevich, A. V.; Antonova, V. P. (2012). "Strong Flux of Low-Energy Neutrons Produced by Thunderstorms". Physical Review Letters (Americal Physical Society) 108 (12). doi:10.1103/PhysRevLett.108.125001.
- ^ Nuclear Power Plant Borssele Reactor Pressure Vessel Safety Assessment, p. 29, 5.6 Neutron Fluence Calculation
See also
- Neutron radiation
- Neutron transport
Fusion power
|
|
Core topics |
- Nuclear fusion
- Timeline
- List of experiments
- Nuclear power
- Nuclear reactor
- Atomic nucleus
- Fusion energy gain factor
- Lawson criterion
- Magnetohydrodynamics
- Neutron
- Plasma
|
|
Nuclear fusion processes and methods
|
|
By confinement |
Gravitational |
- Alpha process
- Triple-alpha process
- Proton-proton chain
- Helium flash
- CNO cycle
- Lithium burning
- Carbon-burning
- Neon-burning
- Oxygen-burning
- Silicon-burning
- S-process
- R-process
- Fusor
- Nova
|
|
Magnetic |
- Tokamak
- Spherical tokamak
- Stellarator
- Spheromak
- Reversed field pinch
- Field-reversed configuration
- Levitated dipole
- Z-pinch
- Dense plasma focus
|
|
Inertial |
- Laser-driven
- Fusor
- Polywell
- Bubble (acoustic)
- H-bomb
- Pure fusion weapon
- Electrostatic
- RF accelerator-driven heavy-ion
|
|
Magnetized inertial |
- Magnetized Liner Inertial Fusion
- Magnetized-target
|
|
Spatial |
- Big Bang nucleosynthesis (BBN)
- Big Crunch nucleosynthesis (BCN; hypothetical)
|
|
|
Other forms |
- Muon-catalyzed
- Pyroelectric
- Migma
|
|
Fusion experimental devices by confinement method
|
|
Magnetic |
Tokamak
|
International
|
|
|
Americas
|
- STOR-M
- Alcator C-Mod
- DIII-D
- UCLA ET
- LTX
- NSTX
- Pegasus
- PBX-M
- TEXT
- TFTR
- ETE
|
|
Asia and
Australia
|
- LT-1
- CT-6
- EAST
- HL-1(M)
- HL-2A
- HT-6(B, M)
- HT-7(U)
- KT-5
- SUNIST
- ADITYA
- SST-1
- IR-T1
- JT-60
- QUEST
- KTM
- GLAST
- KSTAR
|
|
Europe
|
- JET
- COMPASS
- GOLEM
- TJ-I
- Tore Supra
- TFR
- ASDEX Upgrade
- TEXTOR
- FTU
- IGNITOR
- RTP
- ISTTOK
- T-3
- T-4
- T-10
- T-15
- TCV
- START
- MAST
|
|
|
Stellarator
|
Americas
|
|
|
Asia and
Australia
|
- H-1NF
- Lingyun
- CHS
- Heliotron J
- LHD
- TU-Heliac
|
|
Europe
|
- UST-1
- UST-2
- TJ-IU
- TJ-II
- TJ-K
- WEGA
- W7-AS
- W7-X
- Uragan-1
- Uragan-2(M)
- Uragan-3(M)
|
|
|
RFP
|
- RFX
- TPE-RX
- EXTRAP T2R
- MST
|
|
Other
|
- LDX
- SSPX
- MFTF
- MCX
- Polywell
- Dense plasma focus
- MTF
- ZETA
|
|
|
Inertial |
Laser
|
Americas
|
- NIF
- OMEGA
- Nova
- Nike
- Shiva
- Argus
- Cyclops
- Janus
- Long path
|
|
Asia
|
- SG-I
- SG-II
- SG-III
- SG-IV
- GEKKO XII
|
|
Europe
|
- HiPER
- Asterix IV (PALS)
- LMJ
- LULI2000
- ISKRA
- Vulcan
|
|
|
Non-laser
|
|
|
|
International Fusion Materials Irradiation Facility
|
|
UpToDate Contents
全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.
English Journal
- Demonstration of the importance of a dedicated neutron beam monitoring system for BNCT facility.
- Chao DS1, Liu YH2, Jiang SH3.
- Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine.Appl Radiat Isot.2016 Jan;107:312-6. doi: 10.1016/j.apradiso.2015.11.015. Epub 2015 Nov 10.
- The neutron beam monitoring system is indispensable to BNCT facility in order to achieve an accurate patient dose delivery. The neutron beam monitoring of a reactor-based BNCT (RB-BNCT) facility can be implemented through the instrumentation and control system of a reactor provided that the reactor
- PMID 26595774
- Appropriate concrete for nuclear reactor shielding.
- Alhajali S1, Yousef S2, Naoum B3.
- Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine.Appl Radiat Isot.2016 Jan;107:29-32. doi: 10.1016/j.apradiso.2015.09.001. Epub 2015 Sep 7.
- A survey for the neutron activation significant trace-minerals in limestones from different sites in Syria has been carried out. The specific saturation activation radioactivity was calculated and compared to the clearance levels. The results show that the limestone composition varies significantly
- PMID 26408911
- Rare earth elements in core marine sediments of coastal East Malaysia by instrumental neutron activation analysis.
- Ashraf A1, Saion E2, Gharibshahi E2, Mohamed Kamari H2, Chee Kong Y3, Suhaimi Hamzah M4, Suhaimi Elias M4.
- Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine.Appl Radiat Isot.2016 Jan;107:17-23. doi: 10.1016/j.apradiso.2015.09.004. Epub 2015 Sep 12.
- A study was carried out on the concentration of REEs (Dy, Sm, Eu,Yb, Lu, La and Ce) that are present in the core marine sediments of East Malaysia from three locations at South China Sea and one location each at Sulu Sea and Sulawesi Sea. The sediment samples were collected at a depth of between 49
- PMID 26405840
Japanese Journal
- 日米プロジェクトの新しい展開 : PHENIX計画 (プロジェクトレビュー 日米科学技術協力事業TITANプロジェクト)
- 中性子イメージングに向けた外部のこぎり波入力による時間デジタル変換器の設計 (超伝導エレクトロニクス)
- 伊藤 圭介,于 国偉,喜多 祐真 [他]
- 電子情報通信学会技術研究報告 = IEICE technical report : 信学技報 113(232), 77-81, 2013-10-02
- NAID 40019868259
- 27aRF-2 J-PARC MLFにおける中性子ドップラーシフターのUCN出力増強(27aRF 素粒子実験領域,実験核物理領域,理論核物理領域,ビーム物理領域合同 J-PARCと原子核素粒子実験,素粒子実験領域)
- 今城 想平,岩下 芳久,清水 裕彦,吉岡 瑞樹,北口 雅暁,三島 賢二,猪野 隆,有本 靖,關義 親,NOP collaboration
- 日本物理学会講演概要集 68(1-1), 29, 2013-03-26
- NAID 110009642531
★リンクテーブル★
[★]
- 関
- flow、mobilization、solvent、stream、streaming
[★]
- 関
- grippe、influenza