L 38 Present day Material science [4].


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Atomic responses can create alphas, betas, neutrons and gamma radiation (particles or ... Impacts of an atomic blast. The discharged neutrons deliver the fireball by warming ...
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Slide 1

L 38 Modern Physics [4] Nuclear material science  what\'s inside the core and what holds it together  what is radioactivity, halflife  cell based dating  Nuclear vitality atomic parting atomic combination atomic reactors atomic weapons

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Nuclear Reactions and E = mc 2 somewhat mass goes far Energy is discharged in the splitting (separation) of an overwhelming core by neutron siege mass = 240.06 units mass = 239.86 units The additional mass is changed over into motor vitality, which is for the most part in the neutrons.

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Biological impacts of atomic radiation Nuclear responses can create alphas, betas, neutrons and gamma radiation (particles or photons) Nuclear radiation is ionizing radiation, i.e., sufficiently lively to thump electrons out of iotas or atoms Ionizing radiation is conceivably destructive to people on the grounds that the ionization it produces can adjust fundamentally the structure of particles inside a living cell which can prompt modifications of the phone (make them dangerous) or to the passing of the phone

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Hazards of radiation The perils of radiation can be minimized by restricting general presentation The impacts of assimilated dosages or ionizing radiation is measured in a unit called the rem. The impacts of radiation presentation are Short term or intense impacts showing up inside a matter of minutes of introduction Long-term impacts that may show up in years, decades or even in future eras

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Average radiation measurements got by a US inhabitant Source of radiation dosage in mrem/yr* Natural Background radiation Cosmic rays 28 Earth and air 28 Internal radioactive nuclei 39 Inhaled radon 200 Man-made radiation Medical/dental x-yars 39 Nuclear medicine 14 *Current government benchmarks limit presentation to 500 mrem/yr

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Radiation disorder This is the general term connected to the intense impacts of radiation A measurement under 50 rem causes no fleeting sick impacts A measurements of 50 – 300 rem at one time brings on radiation ailment An entire body measurements of 400 – 500 rem is deadly for around half of individuals uncovered Whole body measurements more prominent than 600 rem result in death for all people

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Energy from the core Huge measures of vitality are emitted in two atomic procedures Nuclear parting : part a substantial core in two Nuclear combination : melding two light cores into one

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A ton of vitality from somewhat mass The energies discharged when a huge core experiences splitting or little cores experience combination are colossal contrasted with synthetic energies (e.g. smoldering fossil fuel) When Uranium parts separated around 0.1% of its mass is changed over into vitality Pound for pound, atomic responses discharge around 10 million times more vitality than synthetic responses 1 pound Uranium  1 million gallons of gas

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Fission To part a uranium core separated takes vitality A neutron hitting a uranium core can make it split A neutron can part U-235 into Cs-143 and Rd-90 in addition to a couple of additional neutrons

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The atomic chain response When U-235 parts, by and large 2.5 neutrons are discharged These neutrons can then go ahead to bring about other U-235\'s to part, this subsequent in a chain response This can bring about a cataclysmic procedure with tremendous vitality discharged.

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Reactor versus Bomb If the vitality discharged in an atomic chain response is permitted to continue controlledly, then this can be utilized as a vitality source  atomic reactor If the chain response happens in an uncontrolled way then you have  nuclear bomb Enrico Fermi delivered the principal atomic reactor under the west stands of Stagg Field at the University of Chicago in 1942

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Nuclear reactors The fuel components contain the fissile fuel as poles of 1 cm width. There might be a huge number of such bars stacked together in the reactor center The most widely recognized fuel is enhanced U-235 Some sort of arbitrator material is likewise used to back off the neutrons to make their catch more proficient

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Inside an atomic reactor Control bars

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Nuclear Power Plant Steel and Concrete Containment vessel

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Reactor operation The reactor is normally worked in the purported basic state in which every parting prompts stand out extra splitting. In the basic express the reactor delivers an unfaltering yield of electrical vitality The reactor is planned not to go into the supercritical state – in this express the reactor creates an uncontrolled and expanding measure of vitality which can precipitate it overheat and prompt emergency.

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Controlling the atomic reactor To keep the reactor in the basic express the administrators conform the control poles The control bars can be moved into or out of the reactor center. They contain a component, for example, cadmium or boron which assimilates neutrons. In the event that the reactor is getting excessively hot, the control poles are pushed into the center to back off the chain response The warmth produced inside the fuel poles is diverted by water encompassing the bars

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To begin the reactor the control poles are hauled out of the center To stop the reactor the control bars are pushed into the center Fuel poles

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Nuclear Power Generation France Japan USA

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Plentiful fuel no nursery gasses no harmful discharges non-dirtying proficient force creation must manage atomic waste probability of cataclysmic mischance costly to manufacture Pros and Cons of Nuclear vitality Advantage Disadvantage

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The nuclear (parting) bomb The key is to accomplish a minimum amount of fissionable material if a minimum amount can be accomplished than a self-maintained uncontrolled response jumps out at accomplish minimum amount (60 kg), 2 chunks of a non-minimum amount of U-235 are united rapidly utilizing a gun When the U-235 gets to be supercritical, a calamitous splitting will rapidly transform into a fireball

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Little Boy

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FAT MAN

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Nuclear Fusion Two light cores (like hydrogen) are joined into one, with a huge arrival of vitality If this is finished with an extensive number of cores the vitality is discharged disastrously as a Hydrogen Bomb

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The Hydrogen Bomb A combination bomb discharges vitality by intertwining deuterium with tritium cores to shape helium and neutrons To accomplish this, the hydrogen must be warmed to 100 million C utilizing a parting bomb  atomic Thermonuclear combination is the thing that powers the stars

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Effects of an atomic blast The discharged neutrons deliver the fireball by warming everything around them The ultra hot fireball delivers an extreme glimmer of light, x-beams and gamma beams The blast makes a tremendous weight surge  impact wave Long after the impact there is the aftermath  the creation and arrival of radioactive cores that are diverted noticeable all around

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The End Review on Friday

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Nuclear Physicists Enrico Fermi "Father of the Atomic bomb" Edward Teller "Father of the Hydrogen bomb" Otto Hahn and Lise Meitner Discovered splitting

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ITER-Demonstrate Fusion

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this is a drawing of a chain response http://www.nanopolis.net/subject.php?id=1335

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http://www.pbs.org/wgbh/amex/bomb/sfeature/videos.html In Andrei Sakharov\'s Layer Cake outline, a few layers of light and substantial components were exchanged. High explosives encompassing the Layer Cake would be utilized to implode and light the nuclear bomb at the focal point of the gadget. The nuclear blast would then set off a combination response in the deuterium. http://www.pbs.org/wgbh/amex/bomb/sfeature/effects.html

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