Play Video
1
Beryllium oxide - The Russian Hahn David
Beryllium oxide - The Russian Hahn David's channel
::2012/09/20::
Play Video
2
Perfect Neutron Reflector - Computer Simulation (for Susan)
Perfect Neutron Reflector - Computer Simulation (for Susan)
::2012/07/18::
Play Video
3
Feed the beast- Mindcrack: Ep. 118 -Neutron Reflectors Are Breaking Bad
Feed the beast- Mindcrack: Ep. 118 -Neutron Reflectors Are Breaking Bad
::2014/01/19::
Play Video
4
Idea: Complementary Transmutation Nuclear Reactor
Idea: Complementary Transmutation Nuclear Reactor
::2012/07/13::
Play Video
5
Minecraft 1.4.7 Industrialcraft 2 Modreview/Tutorial Deutsch/German Crafting/Erklärung AKW Teil 3
Minecraft 1.4.7 Industrialcraft 2 Modreview/Tutorial Deutsch/German Crafting/Erklärung AKW Teil 3
::2013/08/06::
Play Video
6
Mods per Negati: IndustrialCraft Parte 9B: Seconda Parte sull
Mods per Negati: IndustrialCraft Parte 9B: Seconda Parte sull'Energia Nucleare! [Tutorial ITA]
::2012/09/29::
Play Video
7
TekkitPedia Episodio 10 - IC2 - Giochicchiando con il Nuclear Reactor e i suoi Components
TekkitPedia Episodio 10 - IC2 - Giochicchiando con il Nuclear Reactor e i suoi Components
::2013/03/27::
Play Video
8
Response to iSuperiorReviews Questions
Response to iSuperiorReviews Questions
::2013/05/10::
Play Video
9
Minecraft Industrial Craft 2 Microcycle Nuclear Reactor Design(Generator, Breeder)
Minecraft Industrial Craft 2 Microcycle Nuclear Reactor Design(Generator, Breeder)
::2013/11/20::
Play Video
10
Программа для создавания скинов Майнкрафт
Программа для создавания скинов Майнкрафт
::2014/06/22::
Play Video
11
Скачать Майнкрафт с кубом по Русски
Скачать Майнкрафт с кубом по Русски
::2014/07/02::
Play Video
12
Программа для создавания скинов Майнкрафт
Программа для создавания скинов Майнкрафт
::2014/06/22::
Play Video
13
Fictionalized Criticality Accident
Fictionalized Criticality Accident
::2007/12/27::
Play Video
14
Скачать Майнкрафт 152 с 100 модами
Скачать Майнкрафт 152 с 100 модами
::2014/06/23::
Play Video
15
Stippling a flashlight reflector
Stippling a flashlight reflector
::2012/09/29::
Play Video
16
ThruNite Neutron 1A review - Short Version
ThruNite Neutron 1A review - Short Version
::2012/11/23::
Play Video
17
Minecraft Nuclear reactor Autoloader system for 1.4.5. Industrial Craft Nuclear Reactor Mark 1 EA*
Minecraft Nuclear reactor Autoloader system for 1.4.5. Industrial Craft Nuclear Reactor Mark 1 EA*
::2013/02/10::
Play Video
18
ThruNite Neutron 1C 2C XM-L Flashlight Review
ThruNite Neutron 1C 2C XM-L Flashlight Review
::2011/02/16::
Play Video
19
Neutrons_Cadmium.avi
Neutrons_Cadmium.avi
::2009/11/15::
Play Video
20
ThruNite Neutron 1A 1AA 2A 2AA XM-L Flashlight Review
ThruNite Neutron 1A 1AA 2A 2AA XM-L Flashlight Review
::2011/02/15::
Play Video
21
Review of the ThruNite Neutron 2C
Review of the ThruNite Neutron 2C
::2011/02/19::
Play Video
22
Porcelana "Reflector"
Porcelana "Reflector"
::2010/06/17::
Play Video
23
ThruNite Neutron 1A review, OH YEAH!!
ThruNite Neutron 1A review, OH YEAH!!
::2011/02/09::
Play Video
24
One-group thermal neutron method, rev 1.avi
One-group thermal neutron method, rev 1.avi
::2012/10/05::
Play Video
25
update on the neutron experiment
update on the neutron experiment
::2009/01/10::
Play Video
26
Thrunite Catapult V3 XML Led (Smooth Reflector)
Thrunite Catapult V3 XML Led (Smooth Reflector)
::2011/04/05::
Play Video
27
Five group delayed neutron calculation
Five group delayed neutron calculation
::2012/08/29::
Play Video
28
How To Make a DIY SteadyCam Tutorial By [ Neutron Studios]
How To Make a DIY SteadyCam Tutorial By [ Neutron Studios]
::2012/05/26::
Play Video
29
Flux in a reactor with a reflector
Flux in a reactor with a reflector
::2012/10/23::
Play Video
30
(1/2) Astronomers Discover Most Massive Neutron Star Yet Known - Part I: Discovery
(1/2) Astronomers Discover Most Massive Neutron Star Yet Known - Part I: Discovery
::2010/10/27::
Play Video
31
Fission cross section for epithemral neutrons inside JSI TRIGA Mark II reactor
Fission cross section for epithemral neutrons inside JSI TRIGA Mark II reactor
::2013/11/05::
Play Video
32
Cantor Dust Reflector (Scaling Test)
Cantor Dust Reflector (Scaling Test)
::2012/04/05::
Play Video
33
Mitrofanov I.G. Neutron survey of planets. Vernadsky Institute. Jan.31, 2013. Part 2 of 2
Mitrofanov I.G. Neutron survey of planets. Vernadsky Institute. Jan.31, 2013. Part 2 of 2
::2013/01/31::
Play Video
34
ThruNite Archer 1A (Video #18)
ThruNite Archer 1A (Video #18)
::2014/03/02::
Play Video
35
The Green Reflectors - Thanks To You
The Green Reflectors - Thanks To You
::2009/03/01::
Play Video
36
Vont, Text on Video - Tutorial en español - El Taller Audiovisual
Vont, Text on Video - Tutorial en español - El Taller Audiovisual
::2014/05/21::
Play Video
37
Silicon optics, windows, lenses, prisms, crystals, wafers sales@dmphotonics.com
Silicon optics, windows, lenses, prisms, crystals, wafers sales@dmphotonics.com
::2013/06/18::
Play Video
38
Lumapower Signature LX Video Review at night with both Tele-Force Head and standard reflector
Lumapower Signature LX Video Review at night with both Tele-Force Head and standard reflector
::2011/02/12::
Play Video
39
Supremacy - Muse - Drum Cover for Mobile Devices
Supremacy - Muse - Drum Cover for Mobile Devices
::2014/06/09::
Play Video
40
Lighting for your YouTube videos! CowboyStudio Triple Lighting Kit Overview
Lighting for your YouTube videos! CowboyStudio Triple Lighting Kit Overview
::2014/03/01::
Play Video
41
Professor Steven Jones cold fusion energy on Cancel The Cabal
Professor Steven Jones cold fusion energy on Cancel The Cabal
::2013/05/18::
Play Video
42
Teach Astronomy - Properties of Pulsars
Teach Astronomy - Properties of Pulsars
::2010/07/24::
Play Video
43
เลนส์น้ำแข็ง
เลนส์น้ำแข็ง
::2013/07/06::
Play Video
44
Critical mass of a reflected reactor, Part 3
Critical mass of a reflected reactor, Part 3
::2012/10/22::
Play Video
45
第29講 Multi-group Calculation (A)
第29講 Multi-group Calculation (A)
::2013/01/11::
Play Video
46
第28講 Homogenious Linear Equation (A)
第28講 Homogenious Linear Equation (A)
::2013/01/11::
Play Video
47
ILL - SANS instrument D11 - 2. Without collimator
ILL - SANS instrument D11 - 2. Without collimator
::2012/07/26::
Play Video
48
Zebralight SC600 flashlight review: Surefire Slayer?
Zebralight SC600 flashlight review: Surefire Slayer?
::2012/11/28::
Play Video
49
A look at the Balder HD1
A look at the Balder HD1
::2012/09/26::
Play Video
50
Mysterious Gamma-Ray Objects Baffle Astronomers | Video
Mysterious Gamma-Ray Objects Baffle Astronomers | Video
::2012/03/22::
NEXT >>
RESULTS [51 .. 101]
From Wikipedia, the free encyclopedia
Jump to: navigation, search

A neutron reflector is any material that reflects neutrons. This refers to elastic scattering rather than to a specular reflection. The material may be graphite, beryllium, steel, tungsten carbide, or other materials. A neutron reflector can make an otherwise subcritical mass of fissile material critical, or increase the amount of nuclear fission that a critical or supercritical mass will undergo. An example of this is the Demon Core, a subcritical plutonium pit that went critical in two separate fatal incidents when the pit's surface was momentarily surrounded by too much neutron reflective material.

Nuclear reactors[edit]

In a uranium graphite chain reacting pile, the critical size may be considerably reduced by surrounding the pile with a layer of graphite, since such an envelope reflects many neutrons back into the pile.

To obtain a 30 year life span, the SSTAR nuclear reactor design calls for a moveable neutron reflector to be placed over the column of fuel. The reflector's slow downward travel over the column would cause the fuel to be burned from the top of the column to the bottom.

A reflector made of a light material like graphite or beryllium will also serve as a neutron moderator reducing neutron kinetic energy, while a heavy material like lead or lead-bismuth eutectic will have less effect on neutron velocity.

Nuclear weapons[edit]

A similar envelope can be used to reduce the critical size of a nuclear weapon, but here the envelope has an additional role: its very inertia delays the expansion of the reacting material. For this reason such an envelope is often called a tamper. The weapon tends to fly to bits as the reaction proceeds and this tends to stop the reaction, so the use of a tamper makes for a longer lasting, more energetic, and more efficient explosion. The most effective tamper is the one having the highest density; high tensile strength is unimportant because no material remains intact under the extreme pressures of a nuclear weapon. Coincidentally, high density materials are excellent neutron reflectors. This makes them doubly suitable for nuclear weapons. The first nuclear weapons used heavy uranium or tungsten carbide tamper-reflectors.

On the other hand, a heavy tamper necessitates a larger high explosive implosion system. The primary stage of a modern thermonuclear weapon may use a lightweight beryllium reflector, which is also transparent to X-rays when ionized, allowing the primary's energy output to escape quickly to be used in compressing the secondary stage.

While the effect of a tamper is to increase efficiency, both by reflecting neutrons and by delaying the expansion of the bomb, the effect on the critical mass is not as great. The reason for this is that the process of reflection is time consuming.

See also[edit]

References[edit]

Wikipedia content is licensed under the GFDL License
Powered by YouTube
LEGAL
  • Mashpedia © 2014